water for energy: addressing the nexus between electricity generation … · 2019. 5. 10. ·...

APRIL | 2019

Water for Energy: Addressing the Nexus between Electricity Generation and Water Resources

ENERGY

iii NATIONAL CONFERENCE OF STATE LEGISLATURES

NATIONAL CONFERENCE OF STATE LEGISLATURES © 2019

The National Conference of State Legislatures is the bipartisan organization dedicated to serving the lawmakers and staffs of the nation’s 50 states, its commonwealths and territories.

NCSL provides research, technical assistance and opportunities for policymakers to exchange ideas on the most pressing state issues, and is an effective and respected advocate for the interests of the states in the American federal system. Its objectives are:

• Improve the quality and effectiveness of state legislatures

• Promote policy innovation and communication among state legislatures

• Ensure state legislatures a strong, cohesive voice in the federal system

The conference operates from offices in Denver, Colorado and Washington, D.C.

Water for Energy: Addressing the Nexus between

Electricity Generation and Water ResourcesGLEN ANDERSEN, MEGAN CLEVELAND, DANIEL SHEA

NATIONAL CONFERENCE OF STATE LEGISLATURES

NATIONAL CONFERENCE OF STATE LEGISLATURES iv

Glossaryn Closed-loop cooling – A method of thermoelectric cooling in which a cooling tower or pond is used to recirculate water and remove excess heat. Cooling towers or ponds allow a portion of the water to evaporate, cooling the remaining water, which is then recirculated back through the system. While these systems require significantly less water to be withdrawn, they consume more water than once-through systems.

n Dry cooling – A method of thermoelectric cooling which relies on ambient air and large fans to condense steam. These systems withdraw and consume negligible amounts of water, but tend to be more expensive than available wet-cooling options while reducing efficiency and output.

n Gigawatt-hour (GWh) – The continuous delivery of one gigawatt of electricity (equal to 1,000 megawatts) over the course of one hour.

n Groundwater – Water existing underneath the Earth’s surface in aquifers and other underground reservoirs.

n Integrated resource plan – A plan designed by an electric utility that outlines how it plans to meet forecasted annual peak demand with supply- or demand-side resources.

n Megawatt-hour (MWh) – The continuous delivery of one megawatt of electricity (equal to 1,000 kilowatts) over the course of one hour.

n Once-through cooling – A method of thermoelectric cooling in which water directly absorbs heat as it flows through a condenser, requiring large volumes of water to be continuously pumped through the system prior to being discharged at or near the source of withdrawal.

n Pumped storage – A system of energy storage in which power is used to pump water to a higher-elevation reservoir or water source when electricity demand is low. Electric power is recovered when water is allowed to flow through a hydro-turbine down to a lower-elevation reservoir or water body when electricity demand is high.

n Renewable portfolio standard (RPS) – Also known as a Renewable Energy Standard (RES), requires utility companies and other electricity suppliers to source a certain amount of energy they sell from designated renewable and clean energy sources.

n Surface water – Fresh, brackish or salt water on the Earth’s surface in the form of lakes, rivers, ponds, streams, oceans and other water bodies as either water sources or receiving bodies for effluents. This can include all forms of both potable and nonpotable waters, including drinking water, recycled water and wastewater.

n Thermoelectric generation – Electric power generated from a heat source, such as burning fossil fuels or through nuclear fission, which produces steam that drives turbines. These generators also require significant amounts of water in their cooling systems, which maintain power plant equipment at manageable temperatures.

n Treated municipal wastewater – Municipal wastewater, or effluent, that undergoes treatment prior to beneficial reuse, such as for power plant cooling operations. This is sometimes known as recycled or reclaimed wastewater.

n Water consumption – Measured as the total amount of water removed from a source that is not directly returned to the source. In terms of power plants, consumed water is the water withdrawn from a source that is lost to evaporation.

n Water intensity – How much water is required to operate certain electric generation resources in relation to the amount of electricity generated.

n Water withdrawals – Measured as the total amount of water removed from a source, even if most of it is returned in a short time to the same or nearby location.

v NATIONAL CONFERENCE OF STATE LEGISLATURES

Contents

Executive Summary ................................................................................................................. 1

Water Use for Electricity Generation ..................................................................................... 3 The Changing Generation Mix ......................................................................................... 4 Water Intensity of Electric Generation Resources.......................................................... 5 Power Plant Cooling Technologies .......................................................................... 6 Hydroelectric Power ................................................................................................ 7 Factors Affecting Water Supply and Demand................................................................. 8 Population Growth and Electricity Demand ........................................................... 8 Water Rights ............................................................................................................. 9 Groundwater ....................................................................................................... 10 Regionality ............................................................................................................... 10 Increased Temperatures and Extreme Weather 12 Technologies for Meeting Energy Water Needs ............................................................. 14 Cooling Technology Retrofits .................................................................................. 14 Energy Efficiency, Emissions and Water Efficiency ................................................ 14 Alternative Water Resources ................................................................................... 15

Key Stakeholders ..................................................................................................................... 17 State Agencies .................................................................................................................. 17 Electric Utilities and Power Plant Owners ...................................................................... 17 State Legislatures ............................................................................................................. 17 Special Purpose Entities ................................................................................................... 17 State Courts ...................................................................................................................... 18 Tribal Governments .......................................................................................................... 18 Public Utility Commissions .............................................................................................. 18 Data Warehouses ............................................................................................................. 18

Federal Laws and Action ......................................................................................................... 19 The Clean Water Act ........................................................................................................ 19 National Pollutant Discharge Elimination System Permitting ............................... 19 Cooling Water Intake Rule ....................................................................................... 20 The Endangered Species Act ........................................................................................... 20 The Federal Power Act .................................................................................................... 21 Renewable Energy Tax Credits ......................................................................................... 21 Reports ............................................................................................................................. 21

State Actions and Policy Options ........................................................................................... 22 Commission Research and Form Working Groups ......................................................... 22 Include Water in Integrated Resource Plans ................................................................... 23 Reduce Water Use Through Renewable Energy and Efficiency Mandates ................... 24 Establish Cooling System Requirements ......................................................................... 26 Include Energy in State Water Planning .......................................................................... 27 Create Environmental Permitting Requirements for Power Plants .............................. 28

Conclusion ............................................................................................................................... 29

Resources ................................................................................................................................. 30

Notes ........................................................................................................................................ 31

1 NATIONAL CONFERENCE OF STATE LEGISLATURES

Executive SummaryWater and electricity generation are inextricably linked—much of the nation’s power generation is dependent on water to op-erate while water systems require a stable supply of electricity for treatment and delivery. Since electricity generation accounts for approximately 45 percent of water withdrawals in the U.S., identifying ways to decrease water use while making sure it is available during shortages, can help create a resilient electric grid while freeing up water for other important societal uses. Popula-tion shifts, a rapidly changing electricity mix, as well as drought and other risks to freshwater availability, are critical factors af-fecting state planners and policymakers as they work to ensure water can sustainably meet electricity generation and other needs for decades to come. This document explores these issues and provides state lawmakers, energy officials and other stake-holders with an array of options they can consider when crafting policies to address energy-water nexus issues.

As state policymakers work to ensure that freshwater supplies can meet the needs of a growing population and a changing electric generation mix, more are considering how policies and plans can be coordinated to reflect the interdependent nature of water and energy systems.

The U.S. Constitution, federal and state legislation, judicial de-cisions and common law allocate authority over water resourc-es between federal, tribal, state and local governments. Water management is primarily a state and local responsibility, and states take a variety of approaches regarding water rights. Al-though much of the authority for water rights allocation and permitting lies with states, federal laws also influence water management.

While the nexus between water and energy is clear, deci-sion-making in the energy-water nexus landscape is fragment-ed and complex. The numerous state entities involved in plan-ning the electric grid seldom coordinate their plans with those responsible for water resource planning and development. The many stakeholders, laws and policies involved in energy and wa-ter systems make crafting effective approaches challenging. The disjointed nature of energy-water nexus decision-making raises a number of concerns for state policymakers, such as how the process can be better coordinated, streamlined and integrated into state planning processes. This document seeks to help an-swer these questions.

Water use for electricity generation should be considered in relation to increasing demands for water from other sectors, shifts in population and the increasing threat of drought. As the population grows, water needs for agriculture and other uses are forecast to grow as well. Temperatures are predicted to continue increasing through the end of the century and are likely to intensify the strain on freshwater resources by increas-

ing evaporation, drought risk and air conditioning needs. Rapid population growth in the arid West, combined with extended drought, has highlighted just how important energy-water nex-us issues can be.

The concerns vary by region, shifting with water use patterns and the energy resource mix. In the West, agricultural irrigation is the largest water user while in the East, a combination of mu-nicipal, industrial and thermoelectric uses account for most with-drawals.1 Challenges to freshwater availability are increasing in some regions and several states have already confronted con-strained water supplies, where drought has led to power plant curtailments or reductions in hydropower electricity production.

While the rapid growth of natural gas, solar photovoltaic and wind generation—driven by state policies as well as econom-ics—is increasing the water efficiency of our generation fleet, water-saving cooling technologies can further decrease the pow-er sector’s water needs.

The focused missions and compartmentalized nature of the state agencies that influence water and energy policy can produce dis-jointed decision-making, inefficiency and additional compliance costs. Recognizing this, states are investigating ways to integrate water and energy into comprehensive planning processes. In Ar-izona, the state Department of Water Resources has committed to educate water and wastewater facility owners and operators about energy- and water-saving opportunities.2 In New Mexico, the comprehensive state energy plan recommended including energy-water nexus issues as part of its Office of State Engineers regional water planning discussions.3

Diverse state approaches have led to a range of water-conserv-ing energy policies across the country. Cooling system require-ments imposed by a number of states have decreased the vol-ume of water withdrawn. In addition, state renewable portfolio standards, efficiency standards and a variety of federal tax in-centives are among the numerous actions that have promot-ed the growth of water-efficient generation technologies while transforming the U.S. power sector.

This document discusses state actions and presents a variety of options that states may wish to consider when crafting poli-cies that address energy-water nexus issues. These include: in-corporating energy-water issues into state planning approach-es; promoting water-efficient cooling technologies for electricity generation; exploring alternative water resources; considering electricity generation sources that use little or no water, such as solar, wind and natural gas technologies; and many others. This report is designed to help decision-makers understand the inter-connections between energy and water, and explore potential solutions as states plan for their future.

NATIONAL CONFERENCE OF STATE LEGISLATURES 2

once-through cooling

recirculating cooling

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Figure 1. How Power Plants Use WaterMost U.S. power plants create steam to drive the turbines that gener-ate electricity. After the steam passes through a turbine, it is cooled, condensed and reused. Steam cooling accounts for virtually all the water that most power plants use, which they often draw from rivers, lakes or aquifers. How much water a power plant uses depends on which cooling technology it uses. Once-through cooling systems (A) withdraw large amounts of water, but return most of it—at a higher temperature—to the source. Recirculating systems (B) take in much less water, but can consume twice as much of it or more, because they evaporate much of the water to condense the steam.

Union of Concerned Scientists, 2011


Water Use for Electricity GenerationSince many power plants require large amounts of water to operate, water access is a critical component of electricity generation. As the nation and the economy have grown, so too have power and water needs. Rising energy demand over the past 70 years has made electricity generation one of the largest water users.

Growing energy demands resulted in steady increases in water withdrawals for thermoelectric plants be-tween 1950 and 1980.4 In more recent decades, energy demand growth has slowed and the amount of water withdrawn for thermoelectric power has actually decreased, in part due to the transition from once-through cooling to recirculating cooling technologies since the 1980s.5 In the coming decades, population growth and increased energy demand—along with a changing generation mix, forecasted regional climat-ic changes, and competing uses for water from agriculture and other sectors—remain the major variables that are likely to affect water availability for electric generation.

According to the U.S. Geological Survey (USGS), in 2010, thermoelectric power accounted for 45 percent of total water withdrawals while irrigation accounted for 38 percent.6 By 2015, thermoelectric power ac-counted for just 41 percent of total withdrawals—an average of 133 billion gallons per day. The last time the U.S. withdrew that little water for electricity generation was in 1965.7

Figure 2 below illustrates changes in water withdrawals for different sectors. Despite population growth, total public water withdrawal and use are decreasing due to demand management, new plumbing codes, water-efficient appliances, efficiency improvement programs and pricing strategies.8

Figure 2. Trends in Water WithdrawalsTotal water withdrawals by water-use category, 1950-2010.

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Source: U.S. Geological Survey, 2018

The Changing Generation MixThe makeup of our electricity supply is shifting rap-idly, with strong implications for water use. Even while electricity demand is expected to rise, the current market favors generators that are relatively less water-intensive.

In 2015, thermoelectric power was responsible for withdrawing around 95 billion gallons of freshwa-ter per day.9

Although coal power plants, which are typical-ly very water-intensive, provided more than half of the nation’s electricity in 2005, coal’s share of the electric mix dropped to approximately 30 per-cent in 2017.10 Much of that capacity has been re-placed by more water-efficient natural gas pow-er plants, which met 31 percent of U.S. electricity needs in 2017. Figure 4 illustrates how dramatical-ly the nation’s generation mix has shifted in the last few decades, and these trends are expected to continue. Amid these changes, nuclear power and hydropower have remained steady, around 20 percent and 7 percent, respectively. Non-hy-dro renewable power—such as solar photovolta-ics (PV) and wind, which use little or no water—has risen from 4 percent of generation in 2010 to nearly 8 percent in 2017.11

Between 2005 and 2010, thermoelectric wa-ter withdrawals declined by around 20 percent.12 They declined another 18 percent between 2010 and 2015. On average, 15 gallons of water was used per megawatt-hour (MWh) of electricity gen-erated in 2015, while 19 gallons per MWh was used in 2010.13

Water Consumption vs. WithdrawalWater use can be divided into two general categories: with-drawal and consumption. Water withdrawal is measured as the total amount of water removed from a source, even if some of it is returned in a short time to the same or nearby loca-tion. Water consumption, when referring to power plant use, is the total amount of water removed that evaporates during the cooling process and is not directly returned to the source. For electric genera-tion, water intensity is designated as the amount of water withdrawn or consumed per MWh of electrici-ty generated. The figure above demonstrates how much water energy generation withdraws relative to other sectors. While thermoelectric power accounted for around 41 percent of total daily withdrawals in 2015, its share of consumption was far lower—in the single digits. The U.S. Geological Survey reported thermoelectric consumptive use for the first time in two decades in its release of 2015 data. According to the USGS report, around 3 percent of thermo-electric withdrawals were consumptive. Despite withdrawing more water, thermoelectric power only consumed around one-twentieth the amount of water as agriculture.

Source: U.S. Geological Survey, 2018

Figure 3. 2015 Withdrawals by CategoryIn billion gallons per day.

Thermoelectric power

Irrigation

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Self-supplied industrial

Aquaculture

Mining

Self-supplied domestic

Livestock

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Total thermoelectric power water withdrawals

132,900 Mgal/day

3.2 %


Figure 4. Electricity Generation from Selected Fuels

U.S. Energy Information Administration www.eia.gov/aeo#AEO2018U.S. Energy Information Administration

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• Fuel prices in the near term drive the share of natural gas-fired and coal-fired generation. In the longer term, the relatively low cost of coal moderates the decline in coal-fired generation in the Reference case.

• Federal tax credits drive near-term growth in renewables generation, moderating growth in natural gas-fired electricity generation except with in the High Oil and Gas Resource and Technologycase, which projects very low natural gas prices.

• Lower natural gas prices in the High Oil and Gas Resource and Technologycase support significantly higher natural gas-fired generation, with less growth in renewables generation than in the Reference case and declining coal-fired generation from 2017 through 2050.

• Higher natural gas prices in the Low Oil and Gas Resource and Technologycase lead to higher levels of coal-fired generation compared with the Reference case, with 460 billion kilowatthours more renewables generation in 2050 than in the Reference case.

—as differences in fuel prices result in significant substitution

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The USGS, which tracks this data, attributes this reduction largely to the increasing number of power plants that have been built or converted to use more efficient cooling systems, as will be discussed later in this re-port. This trend has been furthered in recent years with the retirement of many water-intensive coal units, which have been replaced by more water-efficient natural gas combined cycle plants.14

State policies that promote certain resources can affect water demand. Since natural gas combined cycle plants generate much of their power with combustion turbines, which require no cooling, they use less water. They withdraw approximately one-third as much water as nuclear or coal plants for each mega-watt-hour of electricity generated, while wind and solar PV use little or no water.

In all, six states accounted for two-thirds of the water reductions seen between 2010 and 2015—a combi-nation of policy and market developments. Those states are California, Illinois, North Carolina, Ohio, Penn-sylvania and Texas.15

Water Intensity of Electric Generation ResourcesThe water intensity of electric generators depends on several factors, including the type of fuel, the age of the plant and the cooling system design. While other factors affect water intensity—such as the design and operational efficiency, along with ambient air and water temperatures—fuel and cooling systems are the most influential.

Of the widely deployed resources, nuclear and coal plants have the highest average water intensity.16 Bio-mass power, though less common, can be just as water-intensive. Natural gas combined cycle systems have greater thermal-to-electric efficiencies and generally use anywhere from half (simple cycle plants) to one-third (combined cycle plants) the amount of water that coal and nuclear plants do. Non-thermo-electric technologies, such as solar PV and wind, have water intensities that are near zero. Figure 5 below graphically compares the water intensities of these and other energy resources.

Figure 5. Water Intensities of Electric Generation Sources17

Source: National Renewable Energy Laboratory, 2011

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Due to growing concerns about water intensity, along with requirements imposed by the U.S. Environmen-tal Protection Agency (EPA) to limit withdrawal rates, there has been a recent transition to more water-ef-ficient cooling systems. In 2010, there were 763 units with once-through cooling—systems that require the largest withdrawals of water. By 2016, there were only 463 such units, reflecting a retirement of once-through cooled units and a shift to less water-intensive generation and cooling technologies.18 As a result, the volume of water withdrawn declined by more than 10 percent between 2014 and 2016, while the vol-


ume of water discharged declined by more than 17 percent.19

While a once-through nuclear plant may consume around 300 gallons per MWh, a closed-loop system will consume twice that while also substantially reducing withdrawals. For context, consumption is considered in the hundreds of gallons per MWh while withdrawals are considered in the tens of thousands of gallons per MWh. And while thermoelectric power may have accounted for 41 percent of total water withdrawals, it only accounted for 3 percent of total water consumption in 2015.20

Dry cooling technologies have the potential to eliminate water from the cooling process almost entire-ly and are viewed as a potential solution to further reducing water requirements, particularly helpful for some arid regions.

POWER PLANT COOLING TECHNOLOGIES

There are two basic types of thermoelectric cooling systems: systems that use water for cooling and those that use air. Wet systems can be subdivided into two primary categories: once-through systems and closed-loop (also known as “recirculating”) systems.

Once-through cooling systems are the most water intensive, withdrawing anywhere from 10 to 100 times more than other types of cooling systems. In once-through sys-tems, the water directly absorbs heat as it flows through a condenser, and large vol-umes of water are essential to keeping the water temperature to a manageable lev-el to protect aquatic organisms. However, very little of this withdrawal is consumed and more than 99 percent is returned to the source.21 The temperature at which the wa-ter is returned is higher than when the wa-ter was withdrawn, and federal regulations have been established and implemented within state permitting requirements to en-sure the discharge temperature does not harm wildlife. Regulators have forced power plants to curtail operations on numerous occasions in recent years when discharge temperatures were too high, and at least one nuclear plant had to curtail opera-tions because intake water temperatures were higher than its design permitted.

Since 2010, the number of once-through cooling systems operating in the U.S. has dropped by around 40 percent and the remaining plants currently account for less than a third of U.S. thermoelectric capacity. 22

Closed-loop systems rely on a cooling tower or pond to recirculate water and remove excess heat. Cool-ing towers or ponds allow a portion of the water to evaporate, cooling the remaining water, which is re-circulated back through the system. While these systems require significantly less water to be withdrawn, they consume more water than once-through systems. Closed-loop systems typically withdraw around 2 percent as much water as once-through systems but consume around 2.5 times more.23 In addition, closed-loop systems are more energy-intensive and can require 1 percent of a plant’s output to run them.

Closed-loop systems account for nearly two-thirds of U.S. thermoelectric capacity—around 800 units have cooling towers and over 150 have cooling ponds. Most power plants built today are designed with closed-loop systems.

Dry cooling systems withdraw and consume negligible amounts of water, relying on ambient air and large fans to condense the steam. However, the benefits come at a cost, as the systems tend to be more expen-sive than available wet-cooling options while reducing efficiency and output.24 They can be three to four times the cost of a recirculating wet cooling system and can reduce operating efficiency from 1 percent in a natural gas combined cycle plant to around 7 percent in nuclear, coal and natural gas simple cycle plants.25


The reliance on ambient air is especially limiting in warmer regions. Not only is air less efficient at remov-ing heat than water, but warm air is less efficient than cold air. This means that summer months can lead to a 10 to 15 percent efficiency drop in certain regions.26 However, efficiency losses can be reduced by us-ing hybrid systems that employ towers with both wet and dry components, allowing a power plant to use dry cooling during most of the lower temperature days and wet cooling to compensate for efficiency loss-es as temperatures rise.

The technology has been more widely deployed over the past decade, especially in arid regions, like Texas and the western U.S., in addition to the Northeast. Close to 70 units were outfitted with dry cooling sys-tems, while another four plants had hybrid systems in operation in 2015.

In most cases, wet cooling systems are the least expensive and result in the highest plant output and effi-ciency. Developers must consider the benefits of increased water conservation attained through dry cool-ing systems against the added costs, loss of plant efficiency and output, as well as the long-term costs against long-term water savings.27 Choosing dry cooling for a 500-megawatt (MW) coal steam plant could eliminate the need for around 2.4 billion gallons of water each year, saving the plant up to $10 million each year, depending on the site.28

With an annual cost of between $11 million and $18 million—when factoring in the capital costs, perfor-mance penalties and other operational costs—dry cooling systems may only make sense in certain situa-tions. A hybrid system’s annual costs range from $9.8 million to $13.5 million, while a wet system would cost around $3.5 million each year.29

While it may be a similar story for most nuclear plants, gas-fired plants present a different dynamic. Not only are the capital costs significantly less—anywhere from half to one-third the costs for a coal steam plant—but the performance penalties are less severe. Annual costs for natural gas plant dry cooling sys-tem range from $6.4 million to $9 million, and $4.9 million to $6.9 million for hybrid systems. A closed-loop wet-cooled system has annual costs of a little over $1.5 million.30

HYDROELECTRIC POWER

While operators of thermoelectric power plants can reduce water use through some of the previously discussed methods, continued access to water is vital to the nation’s hydroelectric power plants, which account for approximately 6 percent of U.S. net electricity generation. The U.S. has nearly 80 gigawatts (GW) of hydroelectric generation capacity installed, equivalent to about 7 percent of total installed gener-ation capacity in the U.S.31 At least 15 states have more than 1 GW of installed hydropower capacity, and all but two states—Delaware and Mississippi—use hydropower to fulfill a portion of electricity needs.32

Due to hydrology and, in part, to federal efforts, such as the construction of the Grand Coulee Dam across the Columbia River in the 1930s, the Northwest hosts the greatest hydroelectric generating capacity—ac-counting for more than 40 percent of the nation’s hydropower. Washington leads in hydropower capacity with more than 21 GW of capacity installed, followed by California and Oregon. In three states—Wash-ington, Idaho and Oregon—hydropower accounts for more than 50 percent of in-state generation.33

Most dams were not built for hydroelectric needs and instead serve other functions, including flood man-agement, irrigation, recreation, navigation, fish and wildlife needs, and drinking water supply.34 Those that do generate electricity must meet both power and non-power needs, creating a complex interplay and requiring coordination in planning and facility design.

Extreme weather can result in additional challenges for hydropower production. Due to increased droughts and flooding, as well as the resulting effects on stream flow, hydropower production may fluc-tuate significantly in the coming years.35 The California drought, which began in 2011, caused significant declines in hydropower generation, dropping from 20 percent of state generation before 2011, to ap-proximately 6 percent in 2014.36 By contrast, increased rainfall in California during the winter of 2017 led to bountiful hydroelectric conditions. That year, California’s hydroelectric generation significantly exceed-ed 2016 levels, generating more than 45,000 gigawatt-hours (GWh) of electricity, compared to 31,000 GWh in 2016.37


Factors Affecting Water Supply and DemandPopulation shifts, coupled with climate trends, changes in demand for other water uses, and changes in electricity consumption, are likely to affect how the nation uses water for electric generation in the coming decades. Water use for electricity generation should be considered in the context of potentially increasing demand for water from other sectors, such as agriculture.

While the U.S. has diversified its energy resources in recent years, most electricity is still generated by pow-er plants that use water as a coolant. According to the U.S. Energy Information Administration (EIA), two-thirds of electricity in the U.S. comes from sources that require water for cooling.38

Figure 6. Water Supply and Sustainability Risk Index

Extreme: 29 counties

High: 271 counties

Moderate : 821 counties

Low: 2020 counties

Extreme: 412 counties

High: 608 counties

Moderate : 1,192 counties

Low: 929 counties

[a] No climate change effects

Water supply sustainability risk index (2050) Water supply sustainability risk index (2050)

[b] Climate change effects

Source: Roy, S.B.; Chen, L.; et al, 2012, Projecting Water Withdrawal and Supply for Future Decades in the U.S. Under Climate Change Scenarios

POPULATION GROWTH AND ELECTRICITY DEMAND

According to the U.S. Census Bureau, the U.S. population is expected to grow nearly 20 percent by 2050—a significant increase in the amount of people who will require access to electricity and water. 39

In some areas, like the western U.S., where water resources are already scarce, the population is expect-ed to increase significantly. Utah has projected large population increases for the state and lawmakers and government officials are trying to reconcile how to provide the necessary services for this region.40

The water risk posed by these demographic shifts and changes in weather patterns is illustrated in Fig-ure 6 for the year 2050. These risks are based on local precipitation, water development, susceptibility to drought, projected increases in water use, groundwater dependence and other factors. Image (b) of Figure 6 illustrates the potential effects of climate change on water supply, while image (a) does not consider cli-matic changes.

The demand for electricity is also expected to increase, as data centers, desalination plants, and other en-ergy-intensive technologies proliferate. However, demand is expected to rise slowly as efficiency increases to appliances and other electricity-using equipment, as well as the growth of distributed energy resources, are projected to partially offset growth in demand.41


WATER RIGHTS

The cost and difficulty of appropriating water can influence utility decisions regarding the type of genera-tion, location of the plant and the choice of cooling technology, particularly for prior appropriation states, as explained below. The way states approach regulation can determine how power plants use water, and states with more restrictive surface water rights may see higher groundwater withdrawals. In western states, a higher percentage of groundwater and recycled water is used for power plant cooling systems, likely due to the relative scarcity of surface water.42

States in the eastern U.S., which traditionally have had more abundant water supply, have developed wa-ter law based on riparian rights, which reflects this abundance. Western states have implemented a differ-ent approach, called prior appropriation, due to the scarcity of water resources in this region.

• Riparian rights are common in the eastern half of the U.S. and allow persons owning property adja-cent to a body of water to use as much water as they need, as long as the need is considered “reason-able” and does not interfere with another owner’s needs. Power plants in water-rich riparian areas have less difficulty finding water and tend to use lower-cost cooling approaches that withdraw more water, such as once-through cooling, which improves power generation efficiency.43

• Prior appropriation. Most western states, as well as Texas, follow the prior appropriation doctrine, which is based on a first-come, first-serve approach rather than land ownership or being adjacent to a water source. Water rights are transferred through a variety of mechanisms and markets. The details of prior appropriation systems vary from state to state, and, as with the riparian doctrine, have been modified by state legislatures. Water rights sales and leasing markets have arisen in western states as a way to efficiently value and transfer rights.

Figure 7. Water Governance Policies

Source: U.S. Department of Energy44

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TX

WA

OR NE

OK

CA

ID

MT

WY

NM

AK

NV

UT

CO

AZ

IA

WI

IL

AR

KY

MS

IN

MI

AL

NC

FL

GA

SC

MA

CT

MN

VA

PA

NY

NJ

MD

DE

RI

MO

LA

TN

OH

NHVT

WV

ME

Pure riparian

Regulated riparian

Mixed riparian – prior appropriation

Pure prior appropriation

Prior appropriation, formerly riparian

Other doctrine

While most states base their water law on one of these two approaches, they have implemented them in different ways, with a variety of approaches and enforcement mechanisms, as demonstrated by the water governance policy map in Figure 7. Below are a few examples of how a state’s water code can affect pow-er generation.


Water rights availability was a major concern when Xcel Energy, a large investor-owned utility operating in eight states,45 planned its new Comanche Station Unit 3 near Pueblo, Colo. The Comanche Station, which is coal-fired, is the largest power plant in Colorado. The utility decided to include a more expensive water-ef-ficient hybrid water- and air-cooled condensing system, which consumes about half as much water as tradi-tional closed-loop cooling, rather than undertake the effort and cost of buying local farmers’ agricultural wa-ter rights. The transfer of water rights in Colorado, which follows the prior appropriation doctrine, can only take place if there will be no adverse effects on other senior or junior water rights holders, meaning that only the amount of water used historically can be transferred.46 While the specifics of trading markets and transfer of rights vary from state to state, the effort and cost required to obtain water rights in prior appro-priation states make water reduction strategies and alternative sources more attractive.

Depending on state legal code, water rights may be suspended in certain cases, such as extreme water shortages. The Texas Legislature passed HB 2694 in 2011, which changed the state’s water code to allow the temporary suspension or adjustment of water rights during a drought or other emergency. During the Texas drought in that same year, the Texas Commission on Environmental Quality chose to suspend or cur-tail over 1,200 water rights. They did not suspend junior water rights for power generation needs due to electric reliability concerns.47 California has also curtailed water rights during droughts in 1976, 1987 and 2016.48

GROUNDWATER

Groundwater accounts for less than 1 percent of total thermoelectric power plant withdrawals.49

Just under 600 million gallons of groundwater was withdrawn each day by thermoelectric power plants in 2015, a reduction of more than 100 million gallons each day from 2010.50 And while most states used some amount of groundwater for thermoelectric power, only four states—Arizona, California, Florida and Nevada—withdrew more than 50 million gallons per day.

States have varied approaches when it comes to groundwater rights—some have no limit on the amount a landowner can withdraw, regardless of environmental impacts or effects on other uses. Cal-ifornia, for instance, traditionally has allowed landowners to drill water wells as often and as deeply as they wish and not be required to report how much they withdraw.51 Due to the growing problem of overdrawn and declining aquifers, the state passed the Sustainable Groundwater Management Act in 2014, which, starting in 2020, will require groundwater planning and regulate withdrawals more closely.

Changes in climate, precipitation and evaporation are expected to affect groundwater recharge rates in certain regions.52 Extended droughts can drain groundwater resources, which take many years to recharge. The resulting increase in groundwater withdrawals caused by the California drought depleted aquifers and caused land subsidence, reducing aquifers’ ability to recharge to their previous levels.53 Furthermore, salt-water intrusion presents a growing threat to groundwater, and can affect the quantity and quality of fresh-water in coastal aquifers. As sea levels are projected to rise, areas including the Southeast and Hawaiian Islands are expected to face increasing concerns with saltwater intrusion, which could create increasing desalination needs.54

REGIONALITY

Along with water rights, regional differences in water resources and climate, as well as natural variations in weather patterns and seasonal changes, affect the water resources available. These conditions dictate which water sources can be drawn from to meet water needs. Regions of the country that are rich in fresh-water supplies—including most of the nation east of the Rocky Mountains and the Pacific Northwest—are able to rely on rivers, lakes and reservoirs for much of their water needs. However, arid parts of the country rely more heavily on groundwater and treated municipal wastewater.

Power plants on the coasts may be less concerned with access to sufficient amounts of water, given that they may have easy access to the ocean for cooling purposes, although increased environmental regula-tions can make it difficult to site new plants. Thermoelectric facilities accounted for 97 percent of total


saltwater surface withdrawals in 2015.55 While saltwater can be used for cooling, it can decrease cooling efficiency and requires plants to use corrosion-resistant materials.56 The larger cooling tower and special materials necessary for a power plant using saltwater can increase cooling tower costs by 35 percent to 50 percent.57

The map in Figure 8 indicates the variation in water withdrawals for thermal electricity generation by re-gion, demonstrating that water withdrawal for coal, natural gas and nuclear generation can vary signifi-cantly based on the region.

Figure 8. Water Withdrawal and Generation by Region in 2015

Source: U.S. Department of Energy, 201717

Figure 3. Water Withdrawal and Generation by Region in 2015 The largest water withdrawal regions are dominated by coal and/or nuclear generation. The area of each pie chart corresponds to total power generation in that region. “Other” includes petroleum, other fossil fuel gases, pumped storage, non-biogenic municipal solid waste, batteries, and hydrogen. The eight regions shown in the figure are notional, based upon contiguous groupings of states and their generation mixes, resources, and market structures. Data Source: EIA Form 923 (2015 data, published in 2016).

Coal

Natural gas

Nuclear

Hydroelectric conventional

Non-hydro renewables

Other

<1.0

1.0-10

10-20

20-35

>35

Total thermoelectric water withdrawlBillion gallons per day

Although much of the country does not rely on groundwater for thermoelectric uses—it makes up just 1 percent of total thermoelectric withdrawals—a number of western states do.58 Groundwater accounted for around 67 percent of thermoelectric water withdrawals in Utah, 69 percent in Arizona and nearly 98 percent in Nevada in 2015.59 And while those figures appear high, all represent volumetric decreases from 2010.

One reason for this may be that USGS doesn’t factor treated municipal wastewater into its total withdraw-als, because this water has already been withdrawn for public supply. Factoring in treated municipal waste-water does shift the math when considering total thermoelectric withdrawals for cooling water, especially in western states. However, states are not required to report that data, and in 2015, only half of states did so—although this is a large improvement over 2010, when only Arizona and California did so. 60

When factoring in this data, Arizona’s thermoelectric withdrawals were: 38 percent groundwater, 45 per-cent treated municipal wastewater and 17 percent surface water.61 California, Florida and Texas all use sig-nificant amounts of treated municipal wastewater as well, although this accounts for a small fraction of 1 percent of total withdrawals. However, it is now state policy in California to use municipal wastewater where feasible and to prioritize the use of freshwater for other public uses.


INCREASED TEMPERATURES AND EXTREME WEATHER

Over the past century, the U.S. has experienced changes in the water cycle, which have affected water sup-ply and availability. Observed changes vary by region and include increased amounts of rain falling during heavy precipitation events, increased rain in place of snow during the winter due to warming tempera-tures, earlier snow melt, reduced rainfall, increased temperatures, and increased severity and length of droughts.62

Extreme weather events, such as flooding, droughts and severe storms, are expected to increase in various regions of the country, affecting water quality and quantity. Decreased precipitation may reduce surface and groundwater supplies, while heavy rains can lead to flooding and diminished water quality due to high sediment and contaminant concentrations.63 Extended droughts can affect groundwater recharge rates and saltwater intrusion can affect the quantity and quality of freshwater in coastal aquifers. These extreme changes in water supply have varying consequences for thermoelectric generation. For example, in 2007, droughts in the Southeast caused thermal generators, including Brown’s Ferry nuclear plant in Alabama, to experience shutdowns and curtailments due to water shortages that caused high discharge temperatures. In contrast, record flooding of the Mississippi River basin in 2011 caused substations in Nebraska to shut down.64 More examples are included in the “Water Scarcity Strains Generation in the Southeast” textbox.

Some areas in Oklahoma and Texas are projected to see longer dry spells and several states, including Ar-izona, California, Colorado, Nevada and Utah, are expected to experience more frequent, severe and lon-ger-lasting droughts. Western states are likely to see reduced winter precipitation, decreased snowpack and earlier snowmelt, which are expected to affect water availability.65 In 2015, California saw the lowest April snowpack in the last 65 years, holding only 5 percent of the water it typically holds at that time of year.66 Similarly, in 2015, Washington experienced decreased snowpack and early snow melt. In April, the U.S. Department of Agriculture’s Natural Resources Conservation Service reported that nearly 75 percent of its long-term monitoring sites in Washington had set new record-low snowpack.67 Like other states, Cal-ifornia and Washington rely on mountain snowpack to store water for spring and summer use, and lower snowpack levels generally require the state to build additional reservoirs to capture and store rainwater.

Increasing air temperatures will also affect many aspects of the energy-water equation. Higher tempera-tures can drive energy consumption, reduce the efficiency of power plant cooling technologies and lessen the amount of surface water available by lowering snowpack and increasing evaporation rates.68

The number of cooling degree days69 is expected to increase significantly, depending on the region, which is likely to increase the summer strain on the electric grid.70 An increase in temperatures of 1.8 degrees Fahrenheit, for example, raises electricity demand for air conditioning between 5 percent to 20 percent, potentially increasing water demand for electricity generation.71 The National Academy of Sciences fore-casts that rising temperatures will increase average electricity demand and average peak electricity de-mand in nearly every region of the U.S. through the end of the century.72

Certain regions are likely to see larger temperature variations, which may have varying effects on electric-ity demand, and several regions have already encountered challenges related to temperature increases. The Pacific Northwest experienced record-breaking heat waves in August 2017, leading several electricity balancing authorities to report record-high summer electricity demand on their systems.73 Similarly, in the summer of 2013, the Northeast experienced a severe heat wave, leading to strains on the electric systems in New England, New York and across the mid-Atlantic. Due to the heat and increased air conditioning use, in July, the New York Independent System Operator (NYISO) reported record-breaking electricity demand, which reached an hourly average peak load of 33,955 MW.74 Texas’ grid (ERCOT) has also experienced sev-eral peak records associated with heat waves in recent years, and the state had 80 days above 100 degrees during the 2011 drought. The combination of increased air temperatures and higher air conditioning loads threatened the reliability of Texas’ electricity grid. Water resources were severely strained and the grid operator warned that extended drought conditions could force power plants offline, resulting in a loss of several thousand megawatts of generating capacity.75 During this drought, only one small, 24-MW power plant had to curtail production due to a lack of sufficient water.76 However, a handful of other plants had to import water from new sources and one coal plant was required to add additional pumps to accommo-date lower reservoir levels and reach new water supplies to keep the plant running.77


Hotter temperatures also affect the efficiency of thermoelectric power plants. The colder the water, the more effective the cooling system and the more efficient the plant operations. Higher ambient air tem-peratures raise the temperature of surface water, which means that it takes more water to remove the same amount of waste heat.

High air temperatures can force power plants to run at reduced capacities, lowering the electricity output. A 2003 heat wave in France, which caused record-high temperatures in rivers due to warm discharged wa-ter used to cool the country’s nuclear plants, resulted in curtailed electric generation, making 4,000 mega-watts of electricity unavailable—the equivalent loss of four nuclear plants.78 Higher summer temperatures can cause a confluence of power system challenges by increasing electricity demand for cooling while con-currently reducing output and lowering the carrying capacity of power lines.79 Similarly, in the late 2000s, several states in the southeast experienced droughts that affected power plant operations, as discussed in more detail in the box below.

Water Scarcity Strains Generation in the Southeast

From 2007 through 2009, the southeastern states experienced a drought that caused water shortages, threatened drinking water supply and affected power plant operations. The G.G. Allen and Riverbend coal plants in North Carolina were forced to cut output due to water scarcity while Duke Energy struggled to keep the McGuire nuclear plant water intake system submerged. The Browns Ferry nuclear plant in Alabama was forced to decrease its output to keep the temperature of discharge water within the permitted limit.80 Several power plants in the region rely on the lakes for water resources, including the Joseph M. Farley nuclear plant in Alabama. Due to reduced water flow past the plant, one of the plant’s two generators was taken offline for maintenance in late 2007.81 It is important to note that fewer plants in the East were designed with cooling technologies to ac-commodate low water levels and tend to withdraw more water than those in the West, potentially mak-ing them more susceptible to drought. In Virginia, North Carolina, Michigan and Missouri, freshwater withdrawal intensity was 41 to 55 times greater compared to that in Utah, Nevada and California.82 Georgia, North Carolina, South Carolina and Virginia withdraw a total of 22.5 billion gallons of freshwater daily, 39 percent of which is used in thermoelectric generation.83 Despite the water supply concerns that stemmed from the 2007-2009 drought, the drought event was no more severe than other recent droughts in the region, and the water crisis that occurred during those years has been attributed to population growth and increases in water demand.84 Continuing population growth and drier conditions are expected to decrease future fresh-water availability. Furthermore, saltwater intrusion resulting from rising seas may affect the quantity and quality of freshwater in coastal aquifers, particularly in the Southeast.85

Several plants in the southeastern region have taken steps to address drought by develop-ing contingency plans and modifying intake systems. During the 2007 drought, Georgia’s McIntosh Plant employed its contingency plan because of low water levels.86 The plant later installed a permanent auxiliary pump at a lower depth in the Savannah River, after the river’s water level during the drought nearly fell below the plant’s intake pipes.87 Other strategies being considered include more efficient cooling technologies, using diverse water sources and developing more robust, long-term water conservation plans.

SAVANNAH ELECTRIC AND POWER COMPANY

Georgia’s McIntosh power plant.


Technologies for Meeting Energy Water NeedsTo address the growing water demand of energy generation and the decreases in fresh water availability, power plants can consider several technologies, including cooling technology retrofits and alternative wa-ter resources. These approaches and the associated trade-offs are detailed in this section.

COOLING TECHNOLOGY RETROFITS

Retrofitting a once-through to a closed-loop plant can reduce its water withdrawals by 98 percent, greatly decreasing the water required for a plant to operate, even if water consumption increases. However, these retrofits can be very costly, and are often pursued in order to meet regulatory requirements. The Oyster Creek nuclear plant in New Jersey decided to shut down early, in part due to the higher operating costs that it would have experienced had it complied with requirements to convert its once-through system to a closed-loop system. The economics become even more difficult when retrofitting from a once-through system to a dry cooling system because, depending on the location, it often cannot satisfy cost-benefit analyses. For this reason, full conversion to dry cooling is rarely done, and hybrid wet-dry systems are more commonly considered.

A study that focused on coal- and natural gas-fired power plants in Texas found that conversions of coal plants with once-through systems to closed-loop systems resulted in the best savings—reducing water withdrawal by 98 percent while costing around 0.12 cents for every gallon of water not withdrawn. This is due, in part, to the fact that natural gas-fired plants are already more water-efficient than coal plants. To eliminate 100 percent of cooling withdrawals with a dry cooling system for those same coal plants, it would cost around 0.67 cents per gallon on average—five times more than it cost to eliminate 98 percent of the withdrawals.88

While it may not be technically feasible for some plants to convert to dry cooling, water scarcity can be a significant selling point. The developer of the Ivanpah concentrating solar power (CSP) facility in California’s Mojave Desert has eliminated 90 percent of the water consumption of the typical CSP facility using dry cooling, while two developers of small modular nuclear reactors (SMRs) have proposed systems that can use dry cooling technologies.89

ENERGY EFFICIENCY, EMISSIONS AND WATER EFFICIENCY

The choice of cooling technologies involves a trade-off between water efficiency, pollutant emissions and energy efficiency. While the difference in generating efficiency is minimal between once-through and closed-loop systems, dry cooling can significantly reduce plant efficiency. This results in a higher amount of pollution generated per megawatt-hour for fossil fuel-fired power plants, because less electricity is gen-


erated from burning the same amount of fuel. Not only can this increase a plant’s carbon emissions, but it also affects the power plant’s bottom line by requiring it to purchase more fuel to create the same amount of electricity.

For the typical pulverized coal plant, carbon emissions increase or decrease 2.7 percent for every 1 percent of efficiency lost or gained, respectively.90

ALTERNATIVE WATER RESOURCES

With all the competing interest in water resources, some areas of the country have sought alternative wa-ter supplies. Especially in regions with less abundant water supplies, scarce freshwater resources must be allocated to supply agriculture, municipal systems, energy generation and other competing uses. Many power plant operators in these areas have reduced their reliance on freshwater by using alternative water resources. These sources include treated municipal wastewater, mine pool water, stormwater, water from oil and gas operations, and low-quality groundwater.

Due in part to its availability and consistent supply, treated municipal wastewater is the most common alternative water resource used by power plants in the U.S.91 Sixty-four of the 8,080 power plants in the U.S.—just under 1 percent—use recycled water, generally in recirculating cooling systems, while research suggests that around 50 percent of the coal-fired capacity was located within 10 miles of suf-ficient quantities of recycled water.92 Recycled water is regulated to ensure quality by state and region-al entities. This provides it with an advantage over other alternative water sources, which may be acid-ic or contain high concentrations of dissolved solids and can often require further treatment to satisfy discharge limitations. In some states, like California, recycled water used in power plants with cooling towers must undergo additional treatment, and Florida and Texas have also developed standards for its use by power plants.93

Half of U.S. states reported the use of treated wastewater to USGS in 2015, while only two had reported that information five years earlier. While the use of this alternative water appears to be increasing, it still accounts for a small fraction of all water used in thermoelectric power plants—just over 200 million gal-lons per day, or around 0.1 percent of all water use. Only four states—Arizona, California, Florida and Tex-as—used over 15 million gallons per day of treated wastewater in 2015. And in only three states—Arizona, Colorado and Oklahoma—did treated wastewater account for over 10 percent of total water use by pow-er plants.

In both cases, Arizona was the clear leader, with an average withdrawal of nearly 70 million gallons of treated wastewater daily, accounting for 45 percent of total power plant withdrawals. Much of this is used by the Palo Verde nuclear plant.


The use of recycled water or other alternative water sources brings with it additional challenges that can cause delays and increase costs. Arizona Public Service, the state’s largest utility, commented on this issue in its most recent integrated resource plan (IRP), stating, “The use of alternative water supplies, such as ef-fluent and alternative cooling technologies to reduce potable water usage comes with an additional cost in terms of capital investment and O&M costs, and may have an impact on unit efficiency.”94

Regardless of the challenges it poses, California has moved to make recycled water the cooling water of choice for the state’s new thermoelectric plants. In 2003, the California Energy Commission established a new policy to minimize the use of freshwater in thermoelectric power plants in order to make the sys-tem and the state more resilient to future droughts.95 The policy encourages new plants to either reduce freshwater use through dry cooling technologies or by sourcing recycled water. As illustrated in Figure 9, the policy has been highly successful in transitioning the state away from using freshwater resources for power plant cooling. For the plants that do rely on freshwater, a number provide offsets by funding local water conservation efforts.

Figure 9. Cooling Process for Operating Power Plants in California That Have a Steam Cycle

Wet-cooled: fresh water

Wet-cooled: recycled water

Dry-cooled

25,000

20,000

15,000

10,000

5,0008,400

11,100

4,300

2014

18%

47%

35%8,400

4,000

2003

1,0007%

30%

63%INST

ALLE

D CA

PACI

TY (M

EGAW

ATTS

)

Source: California Energy Commission, 2017

Case Study: Palo Verde Nuclear Generating Station

The Palo Verde nuclear plant in Arizona is the largest power plant of any kind in the country, with three nuclear reactors and a capacity of nearly 4,000 MW.96 Yet it sits in the middle of the desert, without access to a major body of water.

At peak operations, the plant withdraws approximately 80 million gallons of water per day—close to 850 gallons per MWh.97 It uses nine cooling towers and has a retention pond in its closed-loop system. While other Arizona electric generators draw heavily from its groundwater supplies, the Palo Verde plant has entered into an agreement with five cities to use treated wastewater for its cooling systems. The 40-year agreement allows the plant access up to 26 billion gallons of treat-ed municipal wastewater each year while providing these cities with up to $1 billion in revenue.98

Two power plants near Amarillo, Texas, have engaged in a similar approach. The Harrington Sta-tion coal plant and the nearby Nichols Station natural gas plant use around 15 million gallons of Amarillo wastewater per day.99


Key StakeholdersA variety of stakeholders are involved in state-level decision-making on water and electricity. Water law and the interactions between these stakeholders guide water use within a state and region. The following section details the functions of these stakeholders and how they influence policy decisions around water use.

State AgenciesState agencies responsible for water policy decisions can include state departments of natural resources, public health, environment, consumer affairs and licensing, or state geological surveys. For those that wish to acquire water rights for energy generation, the most important agency is the one that issues water use permits and water rights. Often these decisions are made by the state’s division of water, which issues per-mits to water consumers, including power plants.

Water commissions and water boards are bodies whose members are appointed by the governor and who advise in formulating water policy, conduct drought planning, and may also identify priority water rights holders in water scarcity situations. Such priority holders could include those who play a role in operating critical infrastructure, such as power plants. State water departments can also provide financial or tech-nical assistance for stakeholders, as well as provide visibility for related causes and/or successful projects.

Electric Utilities and Power Plant OwnersThe relationship that investor-owned utilities, electric cooperatives and municipally owned utilities have with state agencies can influence how they approach water use and power generation choices. The ap-proach that utilities take in designing their integrated resource plans, and the energy mix that results from these plans, play a significant role in determining how much of a state’s water is consumed for electricity generation.

State LegislaturesState legislators are responsible for setting the budgets for state agency operations, setting the direction of agencies, and directing research on energy and water. They also set energy policies that influence the growth of renewable energy, natural gas, coal and energy efficiency, which can play a pivotal role in deter-mining the water intensity of a state’s energy portfolio. In addition, the legislature creates the framework that shapes the administration, function and sale of water rights.

Legislatures often play a central role in water planning efforts, setting guidelines and direction for state wa-ter commissions in developing water resource plans. North Dakota enacted legislation in 2017 directing the state water commission to develop a biennial comprehensive water development plan. It also designates who shall sit on the water commission and what the commission’s aims will be. Tasks of the commission in-clude, “to provide water for the generation of electric power and for mining and manufacturing purposes.”

Special Purpose EntitiesState and locally created entities may also play a role in water-based decisions. State environmental infra-structure banks, funded through EPA’s Clean Water State Revolving Fund (CWSRF), provide low-interest loans for water infrastructure projects, so their decisions may affect water scarcity and availability of water rights for power plants.100 Also, water brokers, both public and private, facilitate transfers of water and/or water rights, which can affect availability of water rights and water infrastructure development patterns.

Grid operators can also affect the role of water availability in power plant planning. In 2013, the Electric Re-liability Council of Texas, which operates most of the state’s electric grid, began requiring new generators to provide proof of water rights before being included in grid planning models. The council also requires existing plants to submit estimates on the amount of electricity they can generate during the year—the amount of available water during droughts is important to this assessment.101


State CourtsThe state judiciary system can affect the use of water and energy through the decisions made with regard to water rights disputes and other case decisions. For example, in 2016 the Utah Court of Appeals affirmed an earlier court ruling allowing planning for the Green River nuclear plant to continue. The decision upheld a district court’s 2013 ruling that the plant’s diversion of river water to cool the nuclear reactors would not compromise the river.

In another case, a Texas court’s 2013 ruling found that the Texas Commission on Environmental Quality could not give cities or power generators special treatment over more “senior” water rights holders—even if the state finds it necessary to protect the “public health, safety and welfare.” During an unsuccessful ap-peal, the court recognized the commission’s authority to regulate water resources but stated its authority cannot exceed its explicit legislative mandate.

Tribal GovernmentsTribal governments are responsible for making energy and water decisions on tribal lands. Although tribes have inherent sovereign authority and jurisdiction over their lands, the federal government exercises a sig-nificant degree of control and jurisdiction, and tribes are still subject to federal laws and authority. Tribes may also have interests, treaty rights and other authorities that may apply beyond tribal lands. In addition, tribal rights are generally recognized as being senior rights, which adds complexity to the decision-making landscape of the energy-water nexus.

The Supreme Court determined, in Winters v. United States, that the federal government, in establishing reservation lands for tribes, also reserved access to water to fulfill the purpose of the reservation.102 Tribes can rely on the federal government to represent their interests, intervene in water adjudication proceed-ings or negotiate their water rights outside of these proceedings.103 Tribal governments oversee water sys-tem utilities or utility boards and play a role in ensuring that their public water systems comply with federal laws, such as the Safe Drinking Water Act and the Clean Water Act.104

Public Utility CommissionsPublic utility commissions (PUCs), also called public service commissions, regulate utilities, including elec-tric and water utilities. PUCs ensure that utility operations are safe and reliable, determine rates, issue permits for constructing energy infrastructure and facilities, and more. Public utility commissioners are nominated by a state governor, confirmed by the state legislature or in some states are elected. State leg-islatures can assign responsibilities to PUCs, such as soliciting bids for long-term energy contracts, conduct-ing studies or implementing renewable energy programs.

With regulatory authority over investor-owned water and electric utilities, PUCs can shape how utilities address the energy-water nexus. For example, PUCs can require electric utilities to report annual water withdrawal and consumption data, adopt water and electricity rates that encourage conservation, facili-tate partnerships between energy and water utilities, and conduct studies of alternative, less-water inten-sive energy sources.

Data WarehousesData on energy and water generation, transportation and consumption patterns is essential to effective state policy and planning in both sectors; organizations that collect and analyze energy and water use data inform state policy decision-making. The USGS provides real-time and historical surface and groundwater quality and use data, as well as analysis of said data, for states and individual projects.105 State PUCs may also keep track of energy and water data through their collection of utility reports and commissioned re-search and studies. Electric utilities report data on electricity sales and generation mix to PUCs through rate cases and compliance reports for renewable and efficiency standards. Water utilities report water consumption statistics in their rate cases for those PUCs that regulate them. Data.gov provides aggregated data from government agencies on both energy and water as well as a host of other sectors.106


Federal Laws and ActionThe decision-making landscape for energy and water issues is somewhat fragmented and complex, with the U.S. Constitution, federal and state legislation, judicial decisions and common law allocating authority over water resources between federal, tribal, state and local governments. Although much of the authori-ty for water rights allocation and permitting lies with states, several federal laws influence water manage-ment, including the Clean Water Act (CWA), the Safe Drinking Water Act, the Federal Power Act and the Endangered Species Act.

Federal energy law only considers water use in a few specific instances, including the permitting of hydro-power facilities under the Federal Energy Regulatory Commission (FERC) and the permitting of nuclear power plants under the Nuclear Regulatory Commission (NRC).

While several federal laws govern aspects of water, in many cases, federal entities lack authority over wa-ter use decisions. Instead, states have most of the water allocation authority and usually have full admin-istrative rights over the water flowing within their borders. The federal government is authorized to de-velop and manage waters for commercial navigation and flood control, however, and there are several federal laws that guide national water management in ways that affect energy development. These laws include the Clean Water Act, the Endangered Species Act and the Federal Power Act.

In addition to the laws discussed below, the Clean Air Act also has a significant impact on electricity gen-eration and water use for generation. For example, the EPA’s Mercury and Air Toxics Standards (MATS) fi-nalized standards to reduce air pollution from coal and oil-fired power plants under sections 111 and 112 of the 1990 Clean Air Act Amendments.107 Issuing MATS caused a number of older coal-fired plants to shut down and be replaced by generation plants with a lower water-use intensity.

The Clean Water ActPower plants that discharge water into rivers, lakes or streams during once-through cooling cycles, where less than 3 percent of water is consumed, are subject to CWA, which governs the temperature of dis-charged water.108 The act establishes the basic structure for regulating discharges of pollutants into the waters of the U.S. and regulating quality standards for surface water (rivers, lakes, streams, ponds and tributaries). It determines ambient water quality standards, provides financial support for municipal waste-water treatment facilities and manages polluted waters.

The term “waters of the U.S.” currently means any navigable waterways or interstate waters. The EPA has refined this definition to account for recent decisions by the U.S. Supreme Court as to what constitutes “waters of the U.S.”, but this definition is on hold while facing challenges in the courts.

The EPA publishes guidelines around wastewater and runs voluntary programs like Energy Star109 and Wa-terSense,110 which all affect state energy and water use. These policies are discussed in more detail in the Federal Law section below.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM PERMITTING

The National Pollutant Discharge Elimination System (NPDES) permitting system enforces effluent dis-charge111 and temperature limits for thermoelectric plants. “Point” sources of pollution—such as pipes, fa-cilities or man-made ditches—must receive a permit before releasing pollution into surface water. The NP-DES permit defines the amount and type of pollutants that may be discharged with the goal of maintaining water quality at a level that is safe for humans and wildlife.

Permits are usually issued by the state where the facility is located. Under the law, EPA has authorized 46 states to administer the NPDES permitting program through state agencies. In reference to power plant NPDES permits, four states do not currently have EPA-authorized programs: Idaho, Massachusetts, New Hampshire and New Mexico.


COOLING WATER INTAKE RULE

In 2014, the EPA issued a final rule under the CWA which established requirements for existing power plants.112 The rule addresses water withdrawals and the intake systems employed by many power plants to minimize the potential harmful effects of cooling water withdrawals on the aquatic environment—in particular the harmful effects from once-through cooling systems. These systems remove billions of aquat-ic organisms from U.S. waters every year, according to the rule, which requires power plants with once-through systems to deploy more protective cooling water intake technologies.

Existing power plants are required to reduce the amount of aquatic life affected by their systems through a variety of methods and to conduct studies to help determine site-specific controls. New units that add ca-pacity to existing facilities are required to include technologies that reduce potential impacts to a level that is equal to closed-loop systems.

Earlier versions of the rule were issued in 2002 and 2004, which is around the time that recirculating sys-tems saw a dramatic spike in deployment. Several power plants initiated retrofits to follow the regulations, transitioning from once-through systems to recirculating systems. The regulation has made recirculating systems the preferred technology for new power plants going forward.

The final 2014 rule applied to around 544 power plants that each withdraw at least 2 million gallons per day for cooling purposes.

The retrofits required under the rule can be expensive, however. A project to install cooling towers at the Brayton Point Power Station, a four-unit coal plant in Massachusetts, cost more than $600 million.113 For the Oyster Creek nuclear plant in New Jersey, cost estimates were higher and the plant’s owner, Exelon Corp., decided to close the plant in part due to the estimated compliance costs.114

The Endangered Species ActThe Endangered Species Act (ESA) was enacted in 1973 to ensure the conservation of threatened and en-dangered plants and animals and the habitats in which they are found.115 Federal agencies are required to


consult with the U.S. Fish and Wildlife Service (FWS) and the U.S. National Oceanic and Atmospheric Ad-ministration Fisheries Service to ensure that any actions they authorize, fund or carry out are not likely to jeopardize the existence of any ESA-listed species. Additionally, the act makes it illegal to take—defined as harming, wounding or harassing—an endangered species of fish or wildlife. With regard to thermoelectric generation, the ESA may apply to the permitting process for certain facilities. For example, the issuance and maintenance of a federal license for nuclear generating facilities by the Nuclear Regulatory Commis-sion, such as a construction permit or operating license, is subject to the provisions of the ESA.116 The pro-visions of the new CWA 316(b) regulations also require an ESA consult with the services.

The Federal Power Act First enacted in 1920, the Federal Power Act (FPA) established regulations for non-federal hydropower projects to support comprehensive development of rivers for energy generation while preserving them for water supply, flood control, recreation and fish and wildlife.117 Subsequent amendments added require-ments that incorporated fish and wildlife concerns into licensing, relicensing and exemption procedures. The act also granted FERC legal authority to regulate hydroelectric dam licensing and safety.

The Federal Power Act also includes emergency authority—in section 202(c)—that allows the energy secretary to order temporary connections of facilities, and generation, delivery, interchange or transmis-sion of electricity as the secretary determines will best meet the emergency and serve the public interest. Emergency conditions include U.S. engagement in wars and sudden increases in electricity demand and electricity shortages, among other conditions. Most notably, water shortages for generating facilities are also considered an emergency under the FPA. Since December 2000, the U.S. Department of Energy has used emergency authority eight times; however, none of these usages was attributed to water shortages for electricity generation.118

Renewable Energy Tax CreditsIn contrast to some of the other federal laws that regulate various aspects of water use by the electricity sector, the federal tax credits for wind and solar generation have a more indirect effect on water use. The federal government offers two significant tax credits that provide incentives for increasing low-water con-sumption wind and solar power resources: the Investment Tax Credit (ITC) and the Renewable Electricity Production Tax Credit (PTC). These tax incentives have been instrumental to the growth of renewable en-ergy technologies, with solar installations growing more than 1,600 percent since the ITC’s implementa-tion in 2006.119 The PTC has helped wind experience a 140 percent growth rate over the past five years.120

Reports The federal government has taken several actions related to the energy-water nexus, including producing reports and creating incentives for renewable energy. Congress has also introduced several bills with pro-visions related to the energy-water nexus; however, no substantial legislation has been enacted as of April 2019.

Several government agencies have completed studies or produced reports on the energy-water nexus, in-cluding the U.S. Government Accountability Office, the Congressional Research Service and the U.S. De-partment of Energy (DOE). Other agencies, such as the EPA, provide resources on this topic.

The U.S. Government Accountability Office has issued six reports discussing the energy-water nexus since 2009, covering the need for improved federal water use data, key energy-water nexus issues that Congress and federal agencies should consider when developing and implementing national policies for energy and water resources, and other issues.121

The Congressional Research Service, several national laboratories and DOE have also issued reports, which are listed in the Resources section. Among them is DOE’s 2014 energy-water nexus report that provides background on the topic, identifies current trends, and summarizes available energy-water data, data gaps and energy-water nexus policies.122


State Actions and Policy OptionsState governments have an assortment of options available to address energy-water nexus issues, includ-ing commissioning in-depth studies to develop a greater understanding of state needs and appropriate management actions. These options are considered against the backdrop of federal energy and water pol-icy, which can have a major influence on state options and actions.

Commission Research and Form Working GroupsOften, the state agencies that oversee energy issues do not work in coordination with state agencies that oversee water use, resulting in lack of information on energy-water nexus issues in general. However, some states are working to increase coordination and develop a better knowledge base as demonstrated by the case studies that follow.

ARIZONA

Former Arizona Governor Jan Brewer established a Blue-Ribbon Panel on Water Sustainability in 2009. The panel was formed to improve the long-term sustainability of Arizona’s water supplies and was tasked with identifying obstacles to increasing water sustainability and potential strategies to overcome these obsta-cles.123 The panel is divided into five working groups, one of which is the Conservation/Recycling/Efficien-cy/Energy Nexus group.124 This group was directed to make recommendations on statutes, rules, policies and strategies for reducing the water cost of energy and the energy cost of water.

A primary goal identified by the panel was to reduce the amount of water required by Arizona power gen-erators to provide energy. In November 2010, the panel released its final report, which included 18 sets of recommendations to improve water sustainability in Arizona, several of which were designed to address the energy-water nexus.125 These recommendations encompassed five broad categories—education and outreach, standards, information development and research agenda, regulatory improvements and incen-tives—and included improvements to the state’s existing “toolbox” of water management, education and research capabilities.

Of the 18 recommendations made by the panel, roughly half made some degree of progress toward com-pletion by December 2016. These include several recommendations related to matching alternative water supplies to appropriate end uses, developing comprehensive reclaimed water infrastructure standards, fa-cilitating indirect potable water reuse, and encouraging the use of alternative water supplies. The remain-ing half of the recommendations, including those to develop incentives for using alternative water sup-plies, had not been started or had an unknown status.126, 127

Governor Doug Ducey created a Water Augmentation Council in 2015. The Council includes energy and water state agencies, agricultural stakeholders and municipal utilities. It was originally tasked with inves-tigating opportunities to increase water conservation and reduce the energy-intensive impact of water treatment.128 Upon request, the Water Augmentation Council provides direction to the director of the Ari-zona Department of Water Resources (ADWR) on any issues determined to affect water management. The council focuses on implementing water conservation measures in all water use sectors and makes recom-mendations to the ADWR on water conservation.

The Arizona Corporation Commission (ACC), known as a public utility commission in other states, has also conducted research and adopted policy related to the energy-water nexus. In May 2017, ACC Com-missioner Andy Tobin requested an investigation into how to improve ACC’s water loss policy.129 The ACC held two workshops on the topic of water conservation and Tobin drafted a policy statement to address the need for an updated and more collaborative approach to water loss methodology by the commission. The statement includes a section related to addressing the energy-water nexus. The ACC adopted the policy on Sept. 12, 2017.130 A subsequent decision was issued on Sept. 19, 2017, that directed ACC staff to establish the Water Reform Working Group (WRWG). The group was charged with overseeing the ACC’s efforts to coordinate data collection and reporting processes. It also required ACC staff to file a progress report on the establishment, roster and meeting schedule of the WRWG within 60 days of the order’s ef-fective date.131


CALIFORNIA

Former Governor Arnold Schwarzenegger addressed the energy-water nexus issue in 2005 through Execu-tive Order S-3-05, creating a Climate Action Team (CAT) to coordinate statewide greenhouse gas emission reduction efforts and the state’s Climate Adaption Strategy.132 The original mandate for the team was to develop proposed measures to meet the emission reduction targets set forth in the executive order. Since then, CAT has expanded to encompass 11 working groups that coordinate policies among the state agen-cies and departments involved.

One of these working groups is the Water Energy Team (WET-CAT), which works to identify opportunities for large energy and water efficiencies.133 The team, which includes members from 11 state agencies, has over-arching goals to achieve large water and energy savings and efficiencies, reduce greenhouse gas emissions, and reduce or eliminate risks from changing hydrological and ocean conditions. WET-CAT integrates regula-tion with state and federal agency support for planning, research, data analysis, technical tools and funding to leverage regional projects and programs.134 The team also works to strengthen interagency coordination through information sharing to inform actions that can reduce the energy intensity of water use.

TEXAS

After the 2011 drought, the Electric Reliability Council of Texas (ERCOT) performed a study, using a legal-ly required biennial study of transmission and generation capacity, to research how the electric system re-sponded under extreme drought.135 The study concluded that “most generators were prepared for or had contingency plans for a single-year severe drought such as experienced in 2011. The more complex issue for generators in Texas appears to be a multi-year drought when water storage is further diminished.”

Include Water in Integrated Resource PlansOn a regular basis, electric utilities in most states must submit integrated resource plans (IRPs) to state regulators, which outline how they plan to meet forecasted annual peak demand with supply- or de-mand-side resources. The basic components of an IRP—including what data needs to be provided, how often they need to be prepared, and what timeframe they need to cover—are usually outlined in state law or regulation, as is the requirement that the state public utilities commission review and approve the plan.

The rules and requirements of IRPs often reflect the concerns of policymakers, and they have developed and changed substantially over time to touch on issues like fuel prices and price volatility, greenhouse gas emissions and market conditions. “Water in particular is a resource that has not been given much consid-eration in utility integrated resource planning in past decades,” notes a report from the Regulatory Assis-tance Project.136 However, that has started to change.


ARIZONA

Every two years, the ACC requires utilities to submit IRPs that cover the next 15 years and can require util-ities to provide information on past practices and future plans. The ACC has constitutional and statutory authority to engage in rulemaking, including rules that pertain to IRP requirements. In 2010, the ACC re-vised its IRP requirements touching on water use in a way it previously had not, requiring that IRPs include data on air emissions and water consumption. As a result, Arizona Public Service (APS), the state’s largest utility, now tracks water costs and usage as a metric for consideration in its IRPs. While the ACC does not prohibit water-intensive generation, it does require utilities to consider alternatives.137

In its most recent IRP, APS’s plan for reducing water consumption includes: considering alternative cooling technologies and alternative water resources for new power plants; improving the efficiency of water use; retiring existing power plants that consume large amounts of water; reducing the amount of non-renew-able groundwater consumed; and increasing the utility’s reliance on energy efficiency and renewable en-ergy resources.138 APS states that the goal is to reduce groundwater’s share of total water usage from 13 percent to 6.5 percent between 2016 and 2026. The utility expects the portion of total water usage sup-plied by reclaimed water to increase by 3 percentage points in the next 10 years. In addition, while the util-ity anticipates significant growth in electricity demand due to population increases, the combination of re-newable generation and energy efficiency will help reduce the utility’s “water intensity,” which it measures based on gallons per MWh. By 2032, the utility expects to reduce its water intensity from 444 gallons per MWh to 314 gallons per MWh. The greatest reductions in water consumption will come from transitioning from wet-cooling to dry-cooling systems.

Another of Arizona’s largest utilities, the Salt River Project (SRP), also considers water in its electric plan-ning. SRP provides water and electricity to Phoenix and its surrounding areas. When evaluating its re-source portfolios, SRP includes water use as a key planning metric. In its IRP, the utility prioritizes resource portfolios that reduce water intensity and states that changes to SRP’s current generation resource mix are required to lower the utility’s water intensity.139 During 2016, SRP reported avoiding using more than 1.9 billion gallons of water as a result of sustainable resources—including energy efficiency, renewables and hydropower—in its portfolio.140 This year, 3 percent of the utility’s energy generation came from renew-able energy sources and 2 percent from hydropower.141

COLORADO

Other water-constrained states have also started to implement water-inclusive IRPs. In Colorado, the Pub-lic Utilities Commission made changes to IRP requirements in 2010 after the state legislature passed HB 1365, known as the Clean Air-Clean Jobs Act.142 The legislation required utilities to file an emissions-re-duction plan that would reduce emissions from coal-fired power plants, either through emissions control technologies, conversion to natural gas or retirement. Due to the changes in statute, the PUC modified its IRP process to include annual water withdrawal and consumption data for new generators, along with the overall water intensity of each generating system.

In addition, many municipal water utilities engage in a similar process for water resource planning. Inte-grated water resource plans (IWRPs) evaluate the issue from another perspective—largely ensuring mu-nicipal access to quality water supplies. Requirements for statewide or regional plans that integrate the water and energy components into the same process could be considered.

Reduce Water Use Through Renewable Energy and Efficiency MandatesTwenty-nine states, the District of Columbia and three territories have adopted renewable portfolio stan-dards, which require utilities to sell a specified percentage or amount of renewable electricity. An addition-al eight states and one territory have set renewable energy goals.143 Since most solar and wind installations use very small amounts of water to generate electricity, state actions that provide incentives for, or man-date, the adoption of renewable resources, in effect mandate the adoption of low-water energy genera-tion. The Lawrence Berkeley National Lab (LBNL) and the National Renewable Energy Laboratory (NREL) reported that renewable generation used to meet 2013 renewable portfolio standard compliance obli-


gations reduced national water withdrawals by approximately 830 billion gallons and consumption by an estimated 27 billion gallons.144 These reductions are equivalent to approximately 2 percent of total 2013 power-sector water withdrawals and consumption.145 Wind power capacity has increased by more than a third while solar has tripled since that time, making current water savings much higher.

Figure 10. Renewable Portfolio Standards (RPS)

Source: NCSL, 2019

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California offers an example of how RPS policies can decrease water use for energy generation. California’s RPS policy requires that 60 percent of energy must come from renewable sources, such as wind and solar, by 2030.146 This mandate has led to decreases in water consumption, and wind energy alone reduced the state’s water withdrawals for energy production by 2.5 billion gallons in 2014.147

Energy efficiency policies can also conserve water by reducing power plant fuel consumption and cool-ing needs while helping states avoid the construction of costly new generation resources that could draw from a state’s water supply. Twenty-seven states have implemented energy efficiency resource standards (EERS), which require a percentage of energy demand to be met with efficiency. 148

Figure 11. Energy Efficiency Resource Standards (EERS)

Source: American Council for an Energy-Efficient Economy (ACEEE), 2018

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While reducing water intensity of energy generation is a byproduct, and not the specific goal of these pol-icies, some states do consider their water saving benefits. A Colorado statute to promote utility-scale solar mentions “minimizing water use for electric generation” as a benefit of the law.149 The statute instructs the PUC to consider whether acquisition of utility-scale solar resources is in the public interest and to consider whether solar projects “could reduce the consumption of water for electric generation.”

Colorado’s Water Plan highlights the smaller quantity of water required by renewable energy when com-pared to thermal generation as well as the policy goal outlined in the state’s Renewable Electricity Stan-dard to minimize water use for electricity generation.

In several western states, including Arizona, Colorado and Texas, river authorities are given powers to re-strict and manage access to water in certain cases. In Texas, the Legislature granted river authorities the power to initiate or participate in programs intended to encourage more efficient use of water and elec-tricity or reduce overall use of water and electricity.150

In addition to these policies, states can encourage deployment of less water-intensive renewable ener-gy sources through financial incentives, including tax credits and direct cash incentives. Tax incentives are the most common type of financial incentive, and include personal and corporate investment tax incentives, property tax incentives and sales tax incentives. Personal and corporate investment tax in-centives provide a direct reduction in a taxpayer’s liability for a portion of the cost of purchasing and installing a renewable energy system. More than a dozen states offer personal and/or corporate invest-ment tax credits. States have created other incentives, including grants, performance-based standards and feed-in tariffs.

Establish Cooling System RequirementsOther policy options include power plant cooling system requirements. In California, the state has em-barked on a “Once-Through Cooling Phase-Out” in response to EPA’s cooling water intake ruling under the Clean Water Act.151 The policy authorized the state’s water boards—including the State Water Resources Control Board and Regional Water Quality Control Boards—to regulate power plants with once-through cooling systems. The approach offered two compliance options: One, a power plant could reduce its water withdrawals to a level consistent with closed-loop systems—which would require the power plant to ret-rofit its cooling system to be closed-loop or dry cooled. Or two, it could reduce fish impingement mortality and entrapment by 90 percent using operational or structural controls.152 While the regulation’s intended focus was primarily temperature and entrapment of aquatic life, it also addressed water quantity issues by mandating cooling systems that significantly reduce water withdrawals.

When it was approved in 2010, this policy applied to 49 generation units at 19 power plants, which were required to submit their compliance plans in 2011. Based on the submitted plans, around two-thirds of those units will be retired by 2020 and 16 will continue long-term operations. Half of those units will be re-placed with new units using dry cooling technologies, while another six will be repowered. Two units will achieve flow-reduction and impingement compliance through operational controls and the installation of technological controls. In all, water withdrawals from the fleet will have been cut in half by around 2020.153

While cooling system requirements may have played a role in some plant decisions to shut down, opera-tors faced other pressures—including low-cost natural gas and renewable energy as well as other environ-mental regulations.

In addition, a 2003 California Energy Commission policy established significant restrictions on the use of freshwater for thermoelectric power plant cooling.154 The policy directs new power plant developers to propose plants that either use dry cooling technologies or rely on recycled wastewater for cooling. The Cal-ifornia Energy Commission is working with power plant developers to make these alternatives work.

Since 2004, the state has seen close to 9,000 MW of combined-cycle projects built, with nearly 85 percent of that operating capacity relying on dry cooling systems or recycled water, significantly reducing freshwa-ter demand.155 Combined with the once-through cooling system phase-out, these policies have significant-ly reduced the amount of freshwater used in California’s electricity sector.


Include Energy in State Water PlanningState water planning efforts involve a collaborative planning process to develop short- and long-range plans for managing water resources and ensuring adequate supplies. Plans vary depending on the state’s endowment of water, experiences with shortages, and the ways in which water is used in a state. Some may emphasize conservation and management, while others focus on water rights and specific uses, such as agriculture or hydropower. Some, such as New Mexico’s, concentrate on drought management, while others, such as Utah’s, focus on water resource development. Many water plans consider federal require-ments of the Endangered Species Act and Wild and Scenic Rivers Act, including stream flow and habitat preservation.156

KENTUCKY

Kentucky’s water plan recommends assessing drought risks and developing a process to assess vulnerabili-ties related to water needs for electricity production. The plan also recommends establishing the Kentucky Drought Mitigation Team, which includes a representative from the Kentucky Department of Energy, to create a coordinated approach for drought response.

COLORADO

In addition to considering water use in inte-grated resource planning, Colorado also in-corporates energy into state water planning. Former Governor John Hickenlooper direct-ed the Colorado Water Conservation Board (CWCB) to develop Colorado’s Water Plan in 2013. The plan was created to be a road map to guide the state to a more collaborative and cooperative path to manage its water. In creating the plan, the CWCB was directed to work with other agencies and stakeholders, including the Colorado Energy Office. The re-sulting 2016 Colorado Water Plan was com-pleted in November 2015 and included sec-tions discussing the energy-water nexus and water use in energy production.157 Addition-ally, the Colorado Climate Plan discusses the energy-water nexus and summarizes actions the state is taking to address it, such as the state’s Renewable Energy Standard and its potential to reduce water use for electricity generation, and conservation measures that water utilities are implementing.158

CONNECTICUT

The final draft of Connecticut’s State Water Plan, released in early 2018, incorporates several energy consid-erations. The plan is designed to help planners, regulators and lawmakers make informed decisions about managing the state’s water resources in a consistent manner. It encompasses scientific information, policy rec-ommendations and forward-looking steps that create a framework for future water management laws and regulations. The plan includes several provisions related to the energy-water nexus, including a requirement to establish guidelines or incentives for water conservation that include energy efficiency. The plan recommends several near-term steps to take toward its implementation, one of which is to consider topics including the en-ergy-water nexus and how to harmonize energy priorities with stewardship of the state’s water resources. The proposed future water management options discussed in the plan include using non-potable water and flood control impoundments for power generation facilities, among other uses. The plan also recommends incorpo-rating existing local and state plans, such as energy plans, into water management.159


TEXAS

Texas, which has a restructured, competitive energy market, does not tend to employ centralized energy planning and has left decisions about water use for energy generation up to the energy market. Nonethe-less, the state is trending toward more water efficient generation approaches due to the growth of natural gas and renewables. Also, since generators need to acquire and pay for water rights or purchase municipal water, they are choosing low water generation technologies since they are subject to more flexible siting requirements. Due to the competitive prices for wind, and now solar power, Texas has seen rapid expan-sion of these generation sources, which do not require water to operate.

The state has also seen a rapid growth in natural gas combined cycle units, which have much lower water requirements than the coal or nuclear plants they are displacing. Texas has also been adding water-efficient fast-response natural gas reciprocating engines and energy storage to help integrate variable wind and so-lar generation. Since this electric generation technology uses almost no water, it can be located where the plant is optimized for location and need, rather than based on where water resources are located.

Create Environmental Permitting Requirements for Power Plants States may address water protection and conservation by requiring consideration or analysis of the facili-ty’s potential effects on the environment, including water sources, habitats and wildlife. Most states con-sider environmental impacts in the permitting or approval process for generation facilities.160 For example, in South Dakota, the state’s Public Utilities Commission is authorized to prepare or require the preparation of an environmental impact statement prior to issuing a permit.161

Several states require permitting authorities to consider the effects of the proposed facility on water re-sources and aquatic species and their habitats. New Hampshire requires certain facilities to receive a Cer-tificate of Site and Facility from the Site Evaluation Committee.162 Approval is contingent on permit appli-cants demonstrating that facilities will comply with state environmental, fish and wildlife standards, among others. The committee is required to review the proposed facility’s impacts on fisheries, wildlife habitats and endangered species.163

Similarly, in Arizona, the state permitting authority is required to review environmental concerns when cer-tifying proposed power plants. The authority has denied at least one power plant its Certificate of Environ-mental Compatibility due to the potential for groundwater depletion and the loss of habitat for an endan-gered species.164

Washington requires generation facilities with a capacity of 350 MW or greater to obtain approval from the Washington Energy Facility Site Evaluation Council. Before recommending approval of the Site Certifi-cation Agreement to the governor, the council must determine that constructing and operating the facility will have minimal adverse effects on the environment and ecology of the state waters and aquatic life.165

New Mexico generating plants with a capacity of 300 MW or larger are required to obtain a siting permit and the state’s Public Regulation Committee requires these facilities to obtain several other permits before it issues a siting permit.166 Power plants that impound water and/or discharge to groundwater must also apply for a groundwater discharge permit.167


Conclusion As states begin to address energy-water nexus issues, they confront a complex task due to the many stake-holders involved in the water and energy sectors, the lack of coordinated planning between these sectors, and the variety of options that can be considered when approaching this challenge. The purpose of this report is to raise awareness and inspire discussion about where states stand when it comes to address-ing the link between energy and water, ultimately promoting efforts to improve planning around these interconnections.

The diversity of state approaches to energy and water management means there is no single policy or suite of policies that will work across all states. Regional differences in water and energy resource avail-ability, state energy policy, and state water policy all play significant roles in determining which path a state might wish to take when addressing energy-water nexus issues.

One starting point that several states have considered is creating a council or working group to bring to-gether stakeholders and experts that can study the issue and contemplate policies and strategies that can address the energy-water nexus challenge. A working group can help chart a path for increasing communi-cation, collaboration and coordination across state government and between agencies and stakeholders. Incorporating water considerations into integrated resource plans and energy considerations into water planning is another broad approach among states that have taken action. For these efforts to be successful and actionable, resources must be set aside, and tangible outcomes and next steps likely need to be set in the directive or legislation.

Actions taken in some states have reduced the water intensity of energy generation and increased coor-dination between water and energy stakeholders. These include: incorporating water into integrated re-source plans; reducing water use through state goals and requirements for renewable energy and efficien-cy; establishing water efficient cooling system requirements; including energy in state water plans; and addressing water quality in environmental permitting for power plants.

Due to the focused missions and compartmentalized nature of the state agencies that influence water and energy policy, efforts to address energy-water nexus issues can experience disjointed decision-making, in-efficiency and additional compliance costs. In recognition of this, states are investigating ways to integrate water considerations into more comprehensive planning processes. In Arizona, the state energy office has committed to educate water and wastewater facility owners and operators about energy and water sav-ings opportunities. In New Mexico’s comprehensive state energy plan, the state recommended including energy-water nexus issues as part of its Office of State Engineers’ regional water planning discussions.

Although the complexity of the challenge is significant, ensuring coordinated planning around energy gen-eration and water resources is of growing importance, particularly in regions that are experiencing popula-tion growth and freshwater resource challenges. This report will serve as a resource for policymakers who wish to take the first steps toward confronting their state’s energy and water interdependency challenges.


ResourcesGovernment Accountability Office Reports

• “Energy-Water Nexus: Improvements of Federal Water Use Data Would Increase Understanding of Trends in Power Plant Water Use,” October 16, 2009, https://www.gao.gov/products/GAO-10-23.

• “Energy-Water Nexus: Many Uncertainties Remain about National and Regional Effects of Increased Biofuel Production on Water Resources,” November 30, 2009, https://www.gao.gov/products/GAO-10-116.

• “Energy-Water Nexus: A Better and Coordinated Understanding of Water Resources Could Help Mit-igate the Impacts of Potential Oil Shale Development,” October 29, 2010, https://www.gao.gov/products/GAO-11-35.

• “Energy-Water Nexus: Amount of Energy Needed to Supply, Use, and Treat Water is Location-Specif-ic and Can be Reduced by Certain Technologies and Approaches,” March 23, 2011, https://www.gao.gov/products/GAO-11-225.

• “Energy-Water Nexus: Information on the Quantity, Quality, and Management of Water Produced during Oil and Gas Production,” January 9, 2012, https://www.gao.gov/products/GAO-12-156.

• “Energy-Water Nexus: Coordinated Federal Approach Needed to Better Manage Energy and Water Tradeoffs,” September 2012, https://www.gao.gov/assets/650/648306.pdf.

Congressional Research Service Reports

• “Energy-Water Nexus: The Energy Sector’s Water Use,” August 30, 2013, https://fas.org/sgp/crs/misc/R43199.pdf.

• “Energy-Water Nexus: The Water Sector’s Energy Use,” January 23, 2017, https://fas.org/sgp/crs/misc/R43200.pdf.

Department of Energy and National Lab Reports

• U.S. Department of Energy, “The Energy-water Nexus: Challenges and Opportunities,” July 2014, https://www.energy.gov/downloads/energy-water-nexus-challenges-and-opportunities.

https://www.gao.gov/products/GAO-10-23








https://www.gao.gov/assets/650/648306.pdf

https://fas.org/sgp/crs/misc/R43199.pdf




https://www.energy.gov/downloads/water-energy-nexus-challenges-and-opportunities


Notes1. U.S. Global Change Research Program, 2014 National Climate Assessment (Washington, D.C.: U.S. Global Climate

Change Research Program, May 2014), https://nca2014.globalchange.gov/. 2. Arizona Department of Water Resources (ADWR), Arizona Water Initiative (Phoenix, Ariz.: ADWR, 2018),

https://new.azwater.gov/water-initiative. 3. New Mexico Energy, Minerals & Natural Resources Department (EMNRD), New Mexico Energy Policy

& Implementation Plan (Santa Fe, N.M.: New Mexico EMNRD, 2015), http://www.emnrd.state.nm.us/EnergyPolicy/documents/EMNRD_EnergyPolicy.pdf.

4. U.S. Department of Energy (DOE), Environment Baseline Vol. 4: Energy-Water Nexus (Washington, D.C.: U.S. DOE Office of Energy Policy and Systems Analysis, January 2017), https://energy.gov/epsa/downloads/environment-baseline-vol-4-energy-water-nexus; M. Maupin et al., Estimated Use of Water in the United States in 2010 (Reston, Va.: U.S. Department of the Interior, U.S. Geological Survey, 2014), https://pubs.usgs.gov/circ/1405/pdf/circ1405.pdf.

5. U.S. DOE, Environment Baseline Vol. 4: Energy-Water Nexus. Ibid.6. M. Maupin et al., Estimated Use of Water in the United States in 2010.7. C. Dieter et al., Estimated Use of Water in the United States in 2015 (Reston, Va.: U.S. DOI, USGS, 2018), https://

pubs.usgs.gov/circ/1441/circ1441.pdf. 8. Ibid.9. Ibid.10. S. Hoff and J. Winik, Electric Power Sector Consumption of Fossil Fuels at Lowest Level since 1994 (Washington,

D.C.: U.S. Energy Information Administration (EIA), May 29, 2018), https://www.eia.gov/todayinenergy/detail.php?id=33543.

11. O. Comstock, Electricity Generation from Fossil Fuels Declined in 2017 as Renewable Generation Rose (Washington, D.C.: U.S. EIA, March 20, 2018), https://www.eia.gov/todayinenergy/detail.php?id=35412.

12. C. Dieter et al., Estimated Use of Water in the United States in 2015.13. Ibid.14. Ibid.15. Ibid.16. J. Macknick et al., A Review of Operational Water Consumption and Withdrawal Factors for Electricity

Generating Technologies (Golden, Colo.: National Renewable Energy Laboratory, March 2011), https://www.nrel.gov/docs/fy11osti/50900.pdf.

17. Ibid.18. U.S. EIA, Quantity and Net Summer Capacity of Operable Cooling Systems by Energy Source (Washington, D.C.:

U.S. EIA, 2017), https://www.eia.gov/electricity/annual/html/epa_09_03.html.19. U.S. EIA, Electricity Data Browser Source (Washington, D.C.: U.S. EIA, n.d.), https://www.eia.gov/beta/

electricity/data/browser/#/topic/.20. C. Dieter et al., Estimated Use of Water in the United States in 2015. 21. J. Macknick et al., A Review of Operational Water Consumption and Withdrawal Factors for Electricity

Generating Technologies.22. U.S. EIA, Quantity and Net Summer Capacity of Operable Cooling Systems by Energy Source.23. J. Macknick et al., A Review of Operational Water Consumption and Withdrawal Factors for Electricity

Generating Technologies.24. J. Stallings, Economic Evaluation of Alternative Cooling Technologies (Palo Alto, Calif.: Electric Power Research

Institute, January 2012), https://www.epri.com/#/research/landing?lang=en-US—Product Id 1024805. 25. J. Macknick et al., A Review of Operational Water Consumption and Withdrawal Factors for Electricity

Generating Technologies.26. B. Hamanaka, H. Zhao, and P. Sharpe, Comparison of Advanced Cooling Technologies Efficiency Depending on

Outside Temperature (Idaho Falls, Idaho: Idaho National Laboratory, September 2009), https://inldigitallibrary.inl.gov/sites/sti/sti/5394122.pdf.

27. J. Stallings, Economic Evaluation of Alternative Cooling Technologies.28. Ibid.29. Ibid.30. Ibid.31. Oak Ridge National Laboratory (ORNL), 2017 Hydropower Market Report (Oak Ridge, Tenn.: ORNL, prepared for

U.S DOE Water Power Technologies Office, April 2018), https://www.energy.gov/eere/water/downloads/2017-hydropower-market-report.


32. Ibid.33. Ibid.34. U.S. DOE, Hydropower Vision (Washington, D.C.: U.S. DOE Water Power Technologies Office, July 26, 2016),

https://www.energy.gov/eere/water/articles/hydropower-vision-new-chapter-america-s-1st-renewable-electricity-source.

35. U.S. Global Change Research Program, Fourth National Climate Assessment (Washington, D.C.: U.S. Global Change Research Program, November 2018), https://nca2018.globalchange.gov/.

36. M. Bowman, California Drought Leads to Less Hydropower, Increased Natural Gas Generation (Washington, D.C.: U.S. EIA, October 6, 2014), https://www.eia.gov/todayinenergy/detail.php?id=18271.

37. California Energy Commission (CEC), California Hydroelectric Statistics & Data (Sacramento, Calif.: CEC, 2018), http://www.energy.ca.gov/almanac/renewables_data/hydro/.

38. V. Dorjets, Many Newer Power Plants Have Cooling Systems That Reuse Water (Washington, D.C.: U.S. EIA, February 11, 2014), https://www.eia.gov/todayinenergy/detail.php?id=14971.

39. U.S. Census Bureau, 2017 National Population Projections Tables (Washington, D.C.: U.S. Census Bureau, September 6, 2018), https://www.census.gov/data/tables/2017/demo/popproj/2017-summary-tables.html.

40. Utah Division of Water Resources (DWR), The Energy-water Nexus in Utah (Salt Lake City, Utah: Utah DWR, September 2012), https://water.utah.gov/OtherReports/Water%20Energy%20Nexus%20in%20Utah.pdf.

41. U.S. EIA, Annual Energy Outlook 2017 (Washington, D.C.: U.S. EIA, Jan. 5, 2017), https://www.eia.gov/outlooks/aeo/pdf/0383(2017).pdf.

42. C. Dieter et al., Estimated Use of Water in the United States in 2015. 43. U.S. DOE, The Energy-water Nexus: Challenges and Opportunities (Washington, D.C.: U.S. DOE, June 2014),

https://energy.gov/sites/prod/files/2014/07/f17/Water%20Energy%20Nexus%20Full%20Report%20July%202014.pdf.

44. U.S. DOE, Environment Baseline Vol. 4: Energy-Water Nexus.45. Minnesota, Michigan, Wisconsin, North Dakota, South Dakota, Colorado, Texas and New Mexico.46. A.M. Michelson, “Administrative, Institutional, and Structural Characteristics of an Active Water Market,”

Journal of the American Water Resources Association 30, no. 6 (December 1994): 971-982. 47. B. Shaw, (Texas Commission on Environmental Quality), Testimony before the Texas Senate Business &

Commerce Committee, Jan. 10, 2012, https://senate.texas.gov/cmtes/82/c510/0110-TCEQ.pdf. 48. California State Water Resources Control Board (SWRCB), State Water Board Drought Year Water Actions:

Drought and Water Rights Frequently Asked Questions (Sacramento, Calif.: California SWRCB, Feb. 22, 2018 (updated)), http://www.waterboards.ca.gov/waterrights/water_issues/programs/drought/faq.shtml.

49. C. Dieter et al., Estimated Use of Water in the United States in 2015.50. Ibid.51. J. Choy and G. McGhee, Understanding California’s Groundwater (Stanford, Calif.: Stanford University, Woods

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52. U.S. Global Change Research Program, Fourth National Climate Assessment.53. U.S. Environmental Protection Agency (EPA), Saving Water in California (Washington, D.C.: U.S. EPA, September

2015), https://www.epa.gov/sites/production/files/2017-02/documents/ws-ourwater-california-state-fact-sheet.pdf.

54. U.S. Global Change Research Program, Fourth National Climate Assessment.55. C. Dieter et al., Estimated Use of Water in the United States in 2015.56. J. Maulbetsch and M. DiFilippo, Performance, Cost, and Environmental Effects of Saltwater Cooling Towers

(Sacramento, Calif.: California Energy Commission, January 2010), http://www.energy.ca.gov/2008publications/CEC-500-2008-043/CEC-500-2008-043.PDF.

57. C, Harto et al., Saline Water for Power Plant Cooling: Challenges and Opportunities (Argonne, Ill.: Argonne National Laboratory, November 2014), http://www.ipd.anl.gov/anlpubs/2014/11/109681.pdf.

58. Ibid.59. C. Dieter et al., Estimated Use of Water in the United States in 2015.60. M. Maupin et al., Estimated Use of Water in the United States in 2010.61. C. Dieter et al., Estimated Use of Water in the United States in 2015.62. U.S. Global Change Research Program, Fourth National Climate Assessment.63. Ibid. 64. U.S. Global Change Research Program, Third National Climate Assessment (Washington, D.C.: U.S. Global


Change Research Program, 2014), https://nca2014.globalchange.gov/. 65. U.S. Global Change Research Program, Fourth National Climate Assessment.66. U.S. EPA, “Climate Impacts in the Southwest” (Washington, D.C.: U.S. EPA;: Jan. 19, 2017),

https://19january2017snapshot.epa.gov/climate-impacts/climate-impacts-southwest_.html#Reference%201.67. U.S. Department of Agriculture, Washington State Snowpack Melting Early, Experts Say (Spokane, Wash.: U.S.

Department of Agriculture, Natural Resources Conservation Service, April 13, 2015), https://www.nrcs.usda.gov/wps/portal/nrcs/detail/wa/newsroom/releases/?cid=NRCSEPRD338392.

68. U.S. Global Change Research Program, Fourth National Climate Assessment.69. Degree days measure the difference between outdoor temperatures and a temperature that is generally found

comfortable indoors (U.S. EPA “Heating and Cooling Degree Days: https://www.epa.gov/sites/production/files/2016-08/documents/print_heating-cooling-2016.pdf). In the projection referenced, cooling degree days are defined as the number of degrees that a day’s average temperature is above 65 degrees Fahrenheit.

70. Ibid. 71. U.S. Climate Change Science Program, Effects of Climate Change on Energy Production and Use in the

United States (Washington, D.C.: U.S. Climate Change Science Program, February 2008), https://downloads.globalchange.gov/sap/sap4-5/sap4-5-final-all.pdf.

72. M. Auffhammer, P. Baylis, and C.H. Hausman, “Climate Change Is Projected to Have Severe Impacts on the Frequency and Intensity of Peak Electricity Demand Across the United States,” Proceedings of the National Academy of Sciences 114, no. 8 (Feb. 21, 2017): 1886-1891, http://www.pnas.org/content/114/8/1886.full.

73. A. Lee, Northwest Heat Wave Leads to Record Levels of Summer Electricity Demand (Washington, D.C.: U.S. EIA, August 23, 2017), https://www.eia.gov/todayinenergy/detail.php?id=32612.

74. New York Independent System Operator (NYISO), Heat Wave Drives Record Electricity Usage in New York (Rensselaer, N.Y.: NYISO, July 19, 2013), https://www.nyiso.com/documents/20142/3064623/Heat_Wave_Drives_Record_Electricity_Usage_in_New_York_07192013.pdf/1baf09cf-8354-bf3a-e93d-9455e414a7d7.

75. K. Galbraith, “Drought Could Pose Power Plant Problems” Texas Tribune (Austin), Sept. 16, 2011), https://www.texastribune.org/2011/09/16/drought-could-post-problems-texas-power-plants/.

76. Electricity Reliability Council of Texas (ERCOT), October Board Meeting Highlights (Austin, Texas: ERCOT, Oct. 20, 2011), http://www.ercot.com/news/releases/show/451.

77. M. Whited, F. Ackerman, and S. Jackson, Water Constraints on Energy Production: Altering our Current Collision Course (Cambridge, Mass.: Synapse Energy Economics Inc., Sept. 12, 2013), http://www.synapse-energy.com/sites/default/files/SynapseReport.2013-06.CSI_.Water-Constraints.13-010.pdf.

78. The Guardian, Heatwave Hits French Power Production (New York, N.Y.: The Guardian, Aug. 12, 2003), https://www.theguardian.com/world/2003/aug/12/france.nuclear.

79. M. Bartos et al., “Impacts of Rising Air Temperatures on Electric Transmission Ampacity and Peak Electricity Load in the United States,” Environmental Research Letters 11, no. 11 (Nov. 2, 2016), http://iopscience.iop.org/article/10.1088/1748-9326/11/11/114008.

80. K. Averyt et al., Freshwater Use by U.S. Power Plants: Electricity’s Thirst for a Precious Resource (Cambridge, Mass.: Union of Concerned Scientists, November 2011), http://www.ucsusa.org/sites/default/files/legacy/assets/documents/clean_energy/ew3/ew3-freshwater-use-by-us-power-plants.pdf.

81. Ibid.82. Ibid. 83. J. Besse et al., The Water Energy-Nexus in the Southeastern United States: A Baseline Assessment of

Regional Reliability and Documentation of Abatement Solutions (Washington, D.C.: U.S. Department of Energy and Worcester Polytechnic Institute, Dec. 14, 2012), https://web.wpi.edu/Pubs/E-project/Available/E-project-121312-114211/unrestricted/Final_DOE_IQP.pdf.

84. Ibid.85. U.S. Global Change Research Program, Fourth National Climate Assessment.86. J. Besse et al., The Water Energy-Nexus in the Southeastern United States: A Baseline Assessment of

Regional Reliability and Documentation of Abatement Solutions.87. Ibid.88. A, Loew, P. Jaramillo,and H. Zhai, “Marginal Cost of Water Savings From Cooling System Retrofits: A Case Study

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89. World Nuclear Association, Cooling Power Plants (London, United Kingdom: World Nuclear Association,


February 2018 (Updated)), http://www.world-nuclear.org/information-library/current-and-future-generation/cooling-power-plants.aspx.

90. N. Sarunac, M. Ness, and C. Bullinger, “Improve Plant Efficiency and Reduce CO2 Emissions When Firing High-Moisture Coals,” Power Magazine (Nov. 1, 2014), http://www.powermag.com/improve-plant-efficiency-and-reduce-co2-emissions-when-firing-high-moisture-coals/.

91. D. Elcock, , Institutional Impediments to Using Alternative Water Sources in Thermoelectric Power Plants (Argonne, Ill.: Argonne National Laboratory, July 2011), http://www.ipd.anl.gov/anlpubs/2011/08/70656.pdf.

92. Jared Ciferno, Use of Non-Traditional Water for Power Plant Applications: An Overview of DOE/NETL R&D Efforts (Pittsburg, Pa.: National Energy Technology Laboratory, Nov. 1, 2009).

93. J.A. Veil, Use of Reclaimed Water for Power Plant Cooling (Argonne, Ill.: Argonne National Laboratory, August 2007), http://www.ipd.anl.gov/anlpubs/2007/10/59940.pdf.

94. Arizona Public Service Company (APS), 2017 Integrated Resource Plan (Phoenix, Ariz.: APS, April 2017), https://www.aps.com/library/resource%20alt/2017IntegratedResourcePlan.pdf.

95. California Energy Commission (CEC), 2016 Integrated Energy Policy Report, (Sacramento, Calif.: CEC, Feb. 28, 2017), http://docketpublic.energy.ca.gov/PublicDocuments/16-IEPR-01/TN216281_20170228T131538_Final_2016_Integrated_Energy_Policy_Report_Update_Complete_Repo.pdf.

96. Arizona Public Service Company, 2017 Integrated Resource Plan.97. C. Spicer, “Palo Verde Nuclear Plant’s Use of Wastewater Defies Drought,” Cronkite News (Phoenix, Ariz.),

Jan. 1, 2016, https://tucson.com/business/local/palo-verde-nuclear-plant-s-use-of-wastewater-defies-drought/article_59b758cb-1106-5197-84ee-96e3935bd208.html.

98. D. Elcock, Institutional Impediments to Using Alternative Water Sources in Thermoelectric Power Plants. 99. R. Peltier, “Xcel Energy’s Harrington Generating Station Earns Power River Basin Coal User’s Group

Award,” Power Magazine (July 1, 2015), https://www.powermag.com/xcel-energys-harrington-generating-station-earns-powder-river-basin-coal-users-group-award/?pagenum=1.

100. U.S. EPA, Clean Water State Revolving Fund (Washington, D.C.: U.S. EPA, Dec. 17, 2018 (updated)), https://www.epa.gov/cwsrf.

101. E. Pickrell, “Drought Puts Drain on Water Supplies for Power Plants,” Houston Chronicle Fuel Fix (Feb. 6, 2013), http://fuelfix.com/blog/2013/02/06/drought-puts-drain-on-water-supplies-for-power-plants/.

102. R. Anderson, “Water Rights, Water Quality, and Regulatory Jurisdiction in Indian Country,” Stanford Environmental Law Journal 34, no. 2 (September 2015), https://law.stanford.edu/publications/%EF%BF%BCwater-rights-water-quality-and-regulatory-jurisdiction-in-indian-country/.

103. J. Churchet al., “Tribal Water Rights: Exploring Dam Construction in Indian Country,” The Journal of Law, Medicine & Ethics 34, no. 1 (April 1, 2015): 60-63, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4699571/.

104. U.S. EPA, Tribal Governments Role in Safe Drinking Water on Tribal Lands, (Washington, D.C.: U.S. EPA, May 19, 2017 (updated)), https://www.epa.gov/tribaldrinkingwater/tribal-governments-role-safe-drinking-water-tribal-lands.

105. U.S. Geological Survey (USGS), Data and Tools Topics: Water (Reston, Va: USGS, updated Dec. 31, 2018), https://www.usgs.gov/products/data-and-tools/real-time-data/water.

106. Data.gov, Energy (Washington, D.C.: U.S. General Services Administration), https://www.data.gov/energy/. 107. U.S. EPA, Basic Information about Mercury and Air Toxics Standards (Washington, D.C.: U.S. EPA, updated June

8, 2017), https://www.epa.gov/mats/basic-information-about-mercury-and-air-toxics-standards. 108. Clean Water Act (CWA), U.S. Code, vol. 33, secs. 1251 et seq. (1972); USGS, Withdrawal and Consumption of

Water by Thermoelectric Power Plants in the United States, 2010 (Reston, Va.: USGS, 2014), https://pubs.usgs.gov/sir/2014/5184/pdf/sir20145184.pdf.

109. U.S. EPA, Energy Star Homepage (Washington, D.C.: U.S. EPA), https://www.energystar.gov/. 110. U.S. EPA, WaterSense Homepage (Washington, D.C.: U.S. EPA, updated October 24, 2018), https://www.epa.

gov/watersense. 111. More information on the effluent discharge guidelines and a link to the final rules can be accessed on the EPA’s

website: https://www.epa.gov/eg.112. U.S. EPA, Cooling Water Intakes—Final 2014 Rule for Existing Electric Generating Plants and Factories

(Washington, D.C.: U.S. EPA, updated Dec. 22, 2016), https://www.epa.gov/cooling-water-intakes/cooling-water-intakes-final-2014-rule-existing-electric-generating-plants-and.

113. G. Welker, “Big Tower Power: New ‘Twins’ at Somerset’s Brayton Point Dominate Region’s Skyline,” The Herald News (Fall River. Mass.), Oct. 10, 2010, http://www.heraldnews.com/x123454710/BIG-TOWER-POWER-New-twins-at-Somersets-Brayton-Point-dominate-region-s-skyline.


114. B. Wheeler, “Retrofit Options to Comply with 316(b),” Power Engineering (Oct. 1, 2010), http://www.power-eng.com/articles/print/volume-114/issue-10/features/retrofit-options-to-comply-with-316-b.html.

115. Endangered Species Act, U.S. Code, vol. 16, secs. 1531-1544 (1973). 116. M.R. Sackschewsky, Threatened and Endangered Species Evaluation for Operating Commercial Nuclear Power

Generating Plants (Richland, Wash.: Pacific Northwest National Laboratory, January 2004), http://www.pnl.gov/main/publications/external/technical_reports/PNNL-14468.pdf.

117. Federal Power Act, U.S. Code, vol. 16, secs. 791-823d (1920). 118. U.S. DOE, DOE’s Use of Federal Power Act Emergency Authority (Washington, D.C.: U.S. DOE, n.d.), https://

energy.gov/oe/services/electricity-policy-coordination-and-implementation/other-regulatory-efforts/does-use. 119. Solar Energy Industries Association (SEIA), Solar Investment Tax Credit (ITC) (Washington, D.C.: SEIA, June

2018), https://www.seia.org/sites/default/files/inline-files/SEIA-ITC-101-Factsheet-2018-June.pdf. 120. American Wind Energy Association (AWEA), Tax Policy (Washington, D.C.: AWEA, n.d.), http://www.awea.org/

production-tax-credit. 121. U.S. Government Accountability Office (GAO), Improvements to Federal Water Use Data Would Increase

Understanding of Trends in Power Plant Water Use (Washington, D.C.: U.S. GAO, October 2009), https://www.gao.gov/products/GAO-10-23.

122. U.S. DOE, The Energy-water Nexus: Challenges and Opportunities.123. Arizona Department of Environmental Quality (ADEQ), Arizona Corporation Commission (ACC), Arizona

Department of Water Resources (ADWR), Blue Ribbon Panel on Water Sustainability Final Report (Phoenix, Ariz.: ADEQ, ACC, and ADWR, Nov. 30, 2010), http://www.azwater.gov/AzDWR/waterManagement/documents/BRP_Final_Report-12-1-10.pdf.

124. ADWR, Blue Ribbon Panel on Water Sustainability Working Groups Memo (Phoenix, Ariz.: ADWR, Feb. 5, 2010), http://www.azwater.gov/AzDWR/waterManagement/documents/BRPWorkingGroups_w_chairs.pdf.

125. ADEQ, ACC, and ADWR, Blue Ribbon Panel on Water Sustainability Final Report. 126. ADWR, Presentation from Governor’s Water Augmentation Council: Recycled Water Committee (Phoenix, Ariz.:

ADWR, Dec. 5, 2016), http://infoshare.azwater.gov/docushare/dsweb/Get/Document-9518/MASTER%20Presentation%20File_FINAL.pdf.

127. Ibid.128. ADWR, Governor’s Water Augmentation Council (Phoenix, Ariz.: ADWR, n.d.), https://new.azwater.gov/water-

initiative/governor-water-augmentation-council. 129. ACC, Docket Number W-00000A-17-0152 (May 22, 2017), http://edocket.azcc.gov/. 130. ACC, Docket Number W-00000A-17-0152, Open Meeting Memorandum (Sept. 12, 2017), http://docket.

images.azcc.gov/0000182454.pdf. 131. ACC, Docket Number W-00000A-17-0152, Decision Number 76375 (Sept. 19, 2017), http://images.edocket.

azcc.gov/docketpdf/0000182798.pdf.132. CEC, California Climate Action Team & Climate Action Initiative (Sacramento, Calif.: CEC), https://www.

climatechange.ca.gov/climate_action_team/. 133. CEC, Energy-water Team of the Climate Action Team, (Sacramento, Calif.: CEC, n.d.), https://www.

climatechange.ca.gov/climate_action_team/water.html. 134. California Climate Change Policy & Action Team, Climate Change and the Energy-water Nexus: Statewide

Opportunities to Reduce Greenhouse Gases and Adapt to a Changing Climate (Sacramento, Calif.: CEC, California Energy-water Team, 2011), http://www.climatechange.ca.gov/climate_action_team/reports/wetcat/climate_change_waterenergy_nexus.pdf.

135. Black & Veatch, Water Use and Availability in the ERCOT Region: Drought Analysis, Draft Report (prepared for Electric Reliability Council of Texas (ERCOT)) (Overland Park, Kan.: Black & Veatch, July 11, 2013), http://www.ercot.com/content/committees/other/lts/keydocs/2013/ERCOT_Water_Use_and_Availablility_-_DrtRpt_1DF.pdf.

136. R. Wilson and B. Biewald, Best Practices in Electric Utility Integrated Resource Planning: Examples of State Regulations and Recent Utility Plans (Cambridge, Mass.: Synapse Energy Economics and the Regulatory Assistance Project, June 2013), http://www.synapse-energy.com/project/best-practices-electric-utility-integrated-resource-planning.

137. J. Rackley and A. Wasserman, Advancing the Energy-Water Nexus: How Governors Can Bridge Their Conservation Goals (Washington, D.C.: National Governors Association, June 2017), https://www.nga.org/center/publications/advancing-the-energy-water-nexus-how-governors-can-bridge-their-conservation-goals/.

138. Arizona Public Service Company, 2017 Integrated Resource Plan.

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139. Salt River Project (SRP), 2017-2018 Integrated Resource Plan Report (Phoenix, Ariz.: SRP, 2017), https://srpnet.com/about/stations/pdfx/2018irp.pdf.

140. SRP, SRP Conservation & Stewardship Report 2016 (Phoenix, Ariz.: SRP, 2016), http://www.srpnet.com/about/financial/pdfx/SRP_ConservationStrewardship_Report_2016.pdf.

141. SRP, SRP Conservation & Stewardship Report 2016.142. Colorado HB 1365 (2010), http://www.leg.state.co.us/clics/clics2010a/csl.nsf/

fsbillcont/0CA296732C8CEF4D872576E400641B74?Open&file=1365_ren.pdf. 143. J. Durkay and M. Cleveland, M., State Renewable Portfolio Standards and Goals (Denver, Colo.: National

Conference of State Legislatures, updated July 20, 2018), http://www.ncsl.org/default.aspx?tabid=27705. 144. R. Wiser et al., A Retrospective Analysis of the Benefits and Impacts of U.S. Renewable Portfolio Standards

(Berkeley, Calif.: Lawrence Berkeley National Laboratory and National Renewable Energy Laboratory, January 2016), https://emp.lbl.gov/sites/all/files/lbnl-1003961.pdf.

145. R. Wiseret al., A Retrospective Analysis of the Benefits and Impacts of U.S. Renewable Portfolio Standards.146. J. Durkay and M. Cleveland, State Renewable Portfolio Standards and Goals.147. I. Stout, Wind Helps California Power Through Drought (Washington, D.C.: American Wind Energy Association,

Aug. 17, 2017), https://www.aweablog.org/wind-helps-california-power-drought/. 148. American Council for an Energy-Efficient Economy (ACEEE), The 2018 State Energy Efficiency Scorecard

(Washington, D.C.: ACEEE, Oct. 4, 2018), https://aceee.org/research-report/u1808. 149. Colo. Rev. Stat. § 40-2-123: (3)(a). 150. Tex. Water Code Ann. §152.001 et seq.151. Clean Water Act (CWA), U.S. Code, vol. 33, secs. 1251 et seq. (1972), CWA section 316(b). 152. California State Water Resources Control Board (SWRCB), Proposed Amendment to the Water Quality Control

Policy on the Use of Coastal and Estuarine Water for Power Plant Cooling (Sacramento, Calif.: California SWRCB, amended April 7, 2015), http://www.waterboards.ca.gov/water_issues/programs/ocean/cwa316/docs/appendix_a.pdf.

153. California SWRCB, 2018 Report of Statewide Advisory Committee on Cooling Water Intake Structures (Sacramento, Calif.: California SWRCB, March 5, 2018), https://www.waterboards.ca.gov/water_issues/programs/ocean/cwa316/saccwis/docs/20180305_final_saccwis_report.pdf.

154. CEC, Docket 02-IEP-1, 2003 Integrated Energy Policy Report (Sacramento, Calif.: CEC, December 2003), https://www.energy.ca.gov/reports/100-03-019F.PDF.

155. CEC, Water Supply Reliability for Thermal Power Plants in California (Sacramento, Calif.: CEC, June 25, 2015), http://www.energy.ca.gov/siting/documents/2015-06-25_water_supply_reliability.pdf.

156. V. Casado-Pérez et al., “All Over the Map: The Diversity of Western Water Plans,” California Journal of Politics and Policy 7, no. 2 (2015), https://escholarship.org/uc/item/0qk496ds#author.

157. Colorado Water Conservation Board (CWCB), Colorado’s Water Plan (Denver, Colo.: CWCB, Nov. 19, 2015), https://www.colorado.gov/pacific/sites/default/files/CWP2016.pdf.

158. Colorado Department of Natural Resources (DNR), Colorado Climate Plan: State Level Policies and Strategies to Mitigate and Adapt (Denver, Colo.: Colorado DNR, 2018), http://cwcb.state.co.us/environment/climate-change/Pages/main.aspx.

159. Connecticut Water Planning Council (WPC), State Water Plan Connecticut Final Report (Hartford, Conn.: Connecticut WPC, January 2018), https://www.ct.gov/water/cwp/view.asp?a=4801&Q=586878&PM=1.

160. Edison Electric Institute (EEI), State Generation & Transmission Siting Directory (Washington, D.C.: EEI, October 2013).

161. S.D. Codified Laws Ann. §49-41B-21. 162. N.H. Rev. Stat. Ann. §162-H:1 et seq. 163. New Hampshire Site Evaluation Committee, Adopted Rules, http://www.gencourt.state.nh.us/rules/state_

agencies/site100-300.html. 164. U.S. DOE, The Energy-water Nexus: Challenges and Opportunities.165. Wash. Rev. Code §80.50. 166. N.M. Stat. Ann. §62-9-1, §62-9-3.167. N.M. Stat. Ann. §74-6-1, et seq.; New Mexico Environment Department—Ground Water Quality Bureau,

Pollution Prevention Section (Santa Fe, N.M.: New Mexico Environment Department, n.d.), https://www.env.nm.gov/gwb/NMED-GWQB-PollutionPrevention.htm.

William T. Pound, Executive Director

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NCSL Contact:

Glen Andersen NCSL Energy Program Director

[email protected]

This report is part of a series of three papers analyzing the energy-water nexus authored by NCSL and the National Association of State Energy Officials (NASEO).

The report was developed under an agreement with the U.S. Department of Energy. NCSL gratefully acknowledges the U.S. Department of Energy’s support,

research and guidance in drafting this report.

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