Renewable Energy Status and Future
Pitt Center for Energy Seminar
John A. Swanson, Member
National Academy of Engineering
February 23, 2017
• Questions:
– Why is energy so important?
– When is the last time you heard “Energy Shortage”?
– Are electric vehicles “green”?
– What is the energy efficient home of the future?
Introduction
Why is Energy primary?
• Energy – Can produce clean water (Reverse Osmosis, for example)
• Salt water
• Brackish water
– Can be used to make fertilizer
• Water – Irrigation and fertilizer can provide food
• Food – A basic human need for a growing population
• Energy Overview – leading to a renewable focus
• Renewable Opportunities – Pro and Con for each
• The Home of the Future • The Utility of the Future • Renewable progress to 2017 • Will not include technical details • Questions are welcome
Presentation Outline
Things to Consider for Electricity
• Generation
• Transmission
• Storage
– Residential
– Utility
– Net Metering (more later)
• Usage
– Conservation
• Balance of Generation and Usage
Energy Overview
• Energy
– Mobile
• Gasoline, Diesel, CNG, Jet Fuel
• Hybrids, Electric Vehicles, Hydrogen Fuel Cells
• Biodiesel trucks (fleets)
– Stationary (Electricity)
• Fossil Fuels (Coal, Natural Gas, (Oil))
• Nuclear
– Fission (now 20%)
– Fusion
• Renewables
Renewable Energy
• Hydroelectric (Dams, pumped storage) – Most sites already used – Distance from load centers – Electricity available on demand
• Geothermal – Power generation (deep wells)
• Electricity available on demand
– Residential heating/cooling • Energy storage, not energy generation
• Biomass (wood, garbage) • Land Fill Gases • Waves and Currents • Wind
– Land based wind farms – Off-shore wind farms
• Solar – Concentrated solar power (CSP) – Photovoltaic (PV)
Energy Considerations
• Conservation – LED lighting
– Programmable Thermostats
– Insulation
– Air exchangers
• Storage – Heat
– Potential Energy (water, rock filled trains)
– Electricity (Batteries)
– Load shifting (Residential hot water)
– Plug in Electric Vehicles (PEV)
Energy Overview (continued)
• Transmission – Need to balance national energy production/consumption
– Major renewable generation resources are not near population centers
– High Voltage lines are $1 million dollars a mile • Difficult to permit/approve, usually cross multiple states (NIMBY!)
– A national grid would be a major resource (like Interstates) • Reliability, Security
• Suggest burying along existing interstate highway right of way – No NIMBY issues
– Already a network connecting population centers
– DC based, eventually superconductors
• Fission – Currently used technology – US plants are nearing end-of-life – Waste disposal still not solved – California reactor being shutdown because of renewables – Next generation is being developed (SMR)
• Small Modular Reactors (replace one coal power plant) • Improved safety, security • Liquid fuels • Made in factory, delivered by truck, run underground • Argonne National Labs – South Korea • Oak Ridge National Labs – China
• Fusion (“The infinite energy source for the future”) – Research at this stage – 20 years to prototype (and always will be?)
Nuclear Status
Solar Distribution in the United States
• Produced by Temperature Differences • Land Based Wind Turbines
– Efficient use of land (multipurpose) – Located far from consumers (great plains, Texas)
• Wind doesn’t blow all the time (but often does at night)
• Off Shore Wind Turbines – Larger Units – Stronger and more consistent wind – East coast is a good resource, near load centers – NIMBY is an issue
Wind (Solar) Energy
Solar Electric Energy • Utility Scale (10 mW to 10 gW)
– PV (Photovoltaic) ($1.60 per watt) – CSP (Concentrated Solar Power)
• Community Solar (1 mW to 100 mW) – PV ($2.00 per watt)
• Commercial (20 kW to 10 mW) – PV ($2.50 per watt) – Behind the meter (single customer)
• Residential (2 kW to 15 kW) – PV ($3.00 per watt) – Behind the meter (single residence)
• Residential Hot Water (1 kW to 2 kW)
Utility Scale Solar Power
• Photovoltaic farms (Solar fields)
– Two standard configuration • Fixed mount, facing south, rigid frame • Tracking, follow sun east to west
– Generates about 30% more power – Increased generation in morning and evening
– Uses both direct and scattered light – Price parity with natural gas – Requires large single use land areas
• Perhaps sheep or goats for foliage control • Protection for endangered species
– Only provides power when sun is shining (none at night) – $1.60 per watt (but falling fast)
Utility Scale PV Fields
Utility Scale Solar Power
• Concentrated Solar Power (CSP) – Focus direct sun only (Southwest US)
– Parabolic Troughs • Hot oil circulates in transparent pipes at focal point
– Solar Towers • Circular field of heliostats follow the sun
• Focus light on heat exchanged at the top of a tower
• Liquid salt energy storage provides evening energy
• Causes some problems for birds (“smokers”)
• PV is cheaper for same area (but no storage)
Parabolic Troughs
Solar Towers
Ivanpah Solar Electricity Generating System
Bird Hazard (“Smokers’)
Traditional Utility Model
Generation
Transmission
Consumer
Distribution
Coal Natural gas Nuclear
High Voltage (500kV+)
Intermediate Voltage (15,000 V)
Domestic Voltage (240 Volts)
Generation always equal the consumer load (no storage)
Traditional Electricity Customer
Distribution
Customer Load
Solar Hot Water
Solar PV Hot Water Concept
• Installed two systems Sep. 2016
• High use of laundry for animal sanctuary
• Use existing electrical hot water heater
• Each system – 4 320 watt panels ($934) ($0.73 per watt)
– Roof mounting hardware ($420)
– Maximum power point (MPP) controller ($269)
– Direct wire to bottom heater in tank ($130)
– Total Cost per system $1750 ($1.37 per watt)
Best Friends Solar Hot Water
Advantages of Residential PV Solar Power
• Produced at point of use – No utility network loads – No large distribution lines needed
• Environment effects – No noise – No CO2 production – Reduces individual Carbon Footprint – Silicon based panels have no toxic materials
• Improved United States energy independence – Zero fuel cost – Already very independent (coal, natural gas) – Natural gas rapidly replacing coal
PV System Components • Solar Modules (Panels)
– South facing sloped roof is best – Tilted panels on flat roof (tilt at or below latitude) – East, West have slightly lower generation (80-90%) – North is not recommended
• Inverter – Converts DC (Direct Current) from panels to AC
(Alternating Current) to match utility power
• External Disconnect – To protect utility workers
• Electric Meter – In and out measurements
Swanson Roof 2013
Green Key Village Net-Zero Homes
• Lake Ella Road, Lady Lake, FL • 142 Net-zero houses, 3 phases • Houses computer analyzed to be “smart green” • Optimized HVAC, windows, walls, hot water • Energy generated with PV modules on roofs • Beautiful houses, beautiful location • $20,000 to $30,000 premium over standard
construction • Native plants, recycled water for lawns • www.greenkeyvillage.com
Green Key Village
Temple Shalom (37.6 kW)
County Road 101, Oxford, FL
Dog Admissions Building Best Friends Animal Sanctuary
80 modules, 20.4 kW, $40,000
Bright sky, no generation!
Net Metering Customer
Distribution
Customer Load PV Solar Panels
Net Metering (bi-directional)
What is Net Metering?
• If you are generating more than you need – Utility buys excess at current price
• If you need more than you are generating – You buy from utility at current price
• Eliminates the need for local storage – Batteries are expensive
• Net metering common an many states, including FL – Utilities are fighting this in several states, including FL – Amendment 1 on November 2016 ballot is not solar friendly
• “Behind the meter” – Priced at the meter, the highest electricity price
Windstax Vertical Axis Windmill
Rated at 1.8 kW (28 mph wind speed)
Wind and/or Solar Customer
Distribution
Customer Load
PV Solar Panels
Net Metering (bi-directional)
Wind Generation
Chevy Bolt 2017 (PEV)
200 mile range (“Green only if electricity is renewable”) $35,000 18.4 kilowatt-hours of battery storage 120 kilowatt maximum discharge rate Two electric motors, one for city, one to help at higher speeds
Electric Vehicle Customer
Distribution
Customer Load PV Solar Panels
Net Metering (bi-directional)
Wind Generation
EV Auto
Bi-directional?
Residential Generation
Natural Gas Fuel 18 kW $3957 20% eff. $0.21/kWh
Residential Power Components
Emergency Generation
Utility Grid Solar Power
Wind Generation
Load
Net Metering
Passive: No controls required
EV Auto
Fast Charge
Residential Power Components (with storage)
Utility Grid Solar Power
Wind Generation
Aux Power
Storage (Batteries)
Load
Net-Metering Optional
Control: Look at Hybrid Auto Control Software
Energy Storage Technologies
Grid Energy Storage, U.S. Dept. of Energy, December 2013
• Fast Response (Grid Stability)
• Bi-directional (Store or release energy)
• Provides load so generators can operate at optimum (full) load – Run generator at optimum to charge batteries
– Turn off generator when batteries are charged
• Can store energy for long times (days)
• Can supply energy while slower generators come online (gas turbines, for example), adding to grid stability
Battery Benefits
A Storage Cost Projection
(to PV)
T
Local Micro-Grid Power Components
Wind Generation
Transmission Grid Solar Power Community Solar
Aux Power (sufficient for critical needs)
Storage (Batteries)
Residences Businesses Public Services Hospitals, etc.
Bus
Modern Energy Company
Coal Power Plants
PV Solar Farms
Gas Turbines
Wind Farms
Nuclear Power
Control Center
Batteries and ultracapacitors
Pumped Storage
Utility Interconnects
Transmission
Controllable Loads
Data: Weather, Loads, etc.
• Norway hydro used to balance Europe wind
• High Voltage DC Cables Denmark to Norway
– 240 KM long
– 700 mW capacity
• Norway uses excess Europe wind energy
– Reduces hydro production
• When wind is low, increases hydro production
• Not pumped storage, but this could add capacity
Large Scale Storage - Norway
Cost Reductions since 2008
“The Swanson Effect”
The Swanson effect Price of crystalline silicon PV Cells ($/watt)
$10
$70
$20 2013 price $0.74
2013 1977
1977 price $76.67/watt
(Richard Swanson, founder of SunPower Corporation)
And the Trend Continues?
Breakdown of Current Price (2015)
5 kW Price
Solar Panels
Inverter
Racking
Electrical
Permits
Labor
Profit
Total is $12,500
• The weakness of the PV systems is that the sun does not shine 24 hours
• There is no storage in the basic PV system
• Net-metering is a short term fix
• Low cost storage (probably batteries) is the final piece
– Will battery technology follow the price-performance of solar modules?
The Future
Summary
• Residential/Commercial/Community/Utility PV Solar Power is growing rapidly
– It has achieved cost parity with fossil fuels
• Solar Hot Water also good
• On shore wind is even less expensive
• Off shore wind has large potential
• Storage (batteries) are the final piece
• Questions?