wind and solar renewable energy sept, 2011 david wright duke energy
TRANSCRIPT
Wind and Solar Renewable Energy
Sept , 2011Sept , 2011David WrightDavid WrightDuke EnergyDuke Energy
2
What We Will Cover Basics of Utility Electricity History of Wind Energy Science of Wind Energy Types of Wind Turbines Wind Farm Construction Renewable Wind Operations Other Types of Renewable EnergyoSolar, Biomass, Hydroelectric & Geothermal
Renewable Energy - Property Valuation Issues
The ‘Drivers’ of an AC GeneratorSteamWaterHot GasWind
3
The Grid Two Types, Transmission and Distribution
Transmission System Operates at ‘higher’ voltages Covers larger geographic areas Crosses state lines Owned and operated by various entities, Utilities, Federal Government, etc.
Distribution System Operates at ‘lower’ voltages Covers smaller geographic areas Brings power ‘to the people’ Owned and operated by your local utility, CLF&P
4
5
The Grid
http://www.oncor.com/images/content/grid.jpg
6
History of Wind Energy, NASA NASA’s wind turbine program was a partnership between NASA, DOE, and NSF Began in 1973 and continued on until around 1988 Worked with the Bureau of Reclamation on the WTS-4 at Medicine Bow, WY
7
NASA Turbine Program
WTS-4 4MW Hamilton StandardMod 1
Mod 5b
Mod 0a
Mod 2
8
History of Wind Energy, California Wind Rush California tax incentives and improvements in technology led to a boom in
construction starting in the early 1980’s
9
History of Wind Energy, Modern Wind Turbines 3 blade, upwind, HAWT, of massive proportions. Multi MW capacity Constructed both on land, and offshore
10
Science - Wind Shear
Speed shear (left) and directional shear (right). From the National Weather Service at http://www.srh.weather.gov/srh/jetstream/mesoscale/windshear.htm
The change in the wind’s speed, or direction, due to the effects of the earth’s surface
11
Science - Roughness Classes 0.0 = Water Surface 0.5 = Smooth surface, concrete runway, mowed grass 1.0 = Open agricultural areas, very scattered buildings, softly rounded hills 1.5 = Agricultural land with some houses, some sheltering hedgerows, dist 1250 meters 2.0 = Agricultural land with some houses, more sheltering hedgerows, dist 500 meters 2.5 = Agricultural land with many houses, many sheltering hedgerows, dist 250 meters 3.0 = Villages, small towns, many hedgerows, forests, and rough or uneven terrain 3.5 = Large cities with tall buildings 4.0 = Very large cities with tall buildings and skyscrapers
Disruption of wind flow by upstream objects. From (Nelson 2004), his Figure 9.2
Science – Continued Growth The rotor swept area and height of
tower continues to increase
12
Science – Continued Growth Increase in swept area and height of tower
improve production
13
14
Science - Wind Density
15
Types of Wind Turbines Many variations exist in the evolution of wind turbines for
producing electricity Number of blades, 1, 2, 3, 4 etc. Upwind vs. Downwind Vertical axis, (VAWT) vs. Horizontal axis, (HAWT) Synchronous vs. Asynchronous generators Tower height and materials Terrestrial and Off-shore
16
1 Bladed Turbines Not very common Required a counterweight to operate Higher rotational speed Noise and visual intrusion
17
2 Bladed Turbines Saves the cost and weight of one rotor blade Require higher rotational speed than 3 bladed The hub and rotor need to be hinged
18
3 Bladed Turbines The most common design based on years of testing and research Gives good ‘balance’ between cost and energy output Upwind turbine design on tubular towers most prevalent
19
Vertical Axis Wind Turbines Several designs; most commonly referred to as the Darrieus, Savonius,
and Giromill type The only commercially manufactured VAWT, was of the Darrieus design,
by a company called Flo Wind
20
Wind Farm ConstructionWind Farm Construction
12 sites constructed to dateStandard design template
21
How a Wind Turbine Works Most large modern wind turbines work in the same way They are 3 blade, upwind, HAWT, with an asynchronous generator The slow moving rotor is connected to a shaft, which is connected to the
gearbox, and then another shaft is connected to the generator The nacelle is rotated into the wind by an automatic yaw control The rotor speed is governed by ‘pitching’ the blades
22
How a Wind Farm WorksMultiple wind turbines are connected electrically to the grid
23
Wind Farm ConstructionWind Farm Construction
Environmental Concerns
Integration with wildlife
Integration with livestock
Effect on water and erosion
Effect on grass and trees
Leading Causes to Total Avian DeathsLeading Causes to Total Avian Deaths
24*Based on a review of literature and known mortality data conducted in December 2010 (January 2011-Tetra Tech, Inc.)
25
Remote Operations “Eye in the sky” 24/7 coverage 2 employee / shift Approx. 600 turbines / employee 6 states, 12 sites Third party contracts Wind and solar ops New expanded center
Asset Management Land lease payment NERC compliance PPA contract management Parts management Financing activities
Renewable Wind OperationsRenewable Wind Operations
26
Condition-based monitoring Industry leader in this area Allows for small uptower repairs One “find” pays for the system Estimated 2010 O&M expense reduction $1.4MM
Renewable Wind OperationsRenewable Wind Operations
Other Forms of Renewable Energy Renewable Energy is defined as “Energy which comes from natural
resources such as wind, sunlight, rain, tides, and geothermal heat, which are naturally replenished”.
27
Other Forms of Renewable Energy Solar Energy
Solar Photovoltaic Solar Thermal
Biomass Energy Direct Combustion Anaerobic Digestion Biofuels
Hydroelectric Energy Run of River Tidal Wave
Geothermal Energy Direct-use geothermal Hydrothermal geo-energy
28
Growth Moving Forward
In 2010, Duke Energy started with 3 solar energy plants.
By the end of 2012 Duke will own approximately 20 sites Nation Wide. As time goes on, Duke Energy plans to continue to grow and expand
their solar business investing more interest in clean renewable energy sources.
30
1,900 MW
2012
Solar Energy
31
Photovoltaic Panels
Ground Mount Fixed
Ground Mount with Tilt Drivers
Roof Top Panels
Solar Photovoltaic
Solar Photovoltaic
33
Solar Photovoltaic Solar cell – A semiconductor device which generates direct current (DC)
electricity when exposed to sunlight. Also known as a photovoltaic cell. Each cell generates approximately 0.5 volt. Solar cells can be wired in series or in parallel to produce higher voltage and current. Made from crystalline silicon or thin film amorphous silicon
Solar Panel – A collection of solar cells, wired in series and/or in parallel, and enclosed in a protective housing.
34
Power inverters These panels will create DC current that will be sent to
a power inverter to make ituseable, AC current.
Standardizing Panels continue to get smaller
while improving power output Duke Plans to wait for technology
to settle into it’s most efficient product before standardizing.
Solar Photovoltaic
Solar Photovoltaic
36
Solar Thermal
Direct heating of air, water, solids,
Heat transfer for power generation
37
2 Basic Designs
Biomass Energy Biomass – A renewable energy source from organic matter such as plants,
animal wastes, and algae Biomass gives off energy in one of several ways
Thermal Conversion – Combustion Chemical Conversion – ‘Black Liquor’ Biochemical Conversion – Fermentation and Anaerobic Digestion.
38
Anaerobic Digestion Anaerobic digestion – A series of processes in which microorganisms
break down biodegradable material in the absence of oxygen, used for industrial or domestic purposes to manage waste and/or to release energy.
39
Hydroelectric
40
Run of River Hydroelectric Wave Energy Tidal Energy
Geothermal Energy
41
2 Main uses of geothermal energy Direct-use geothermal – Primarily heat pumps, storage. For space heating. Hydrothermal geo-energy – Use of stored heat in magma to heat water/steam to
produce electricity.
42
Valuation Issues - Government Incentives
• Production Tax Credits• This is a per KW production tax credit.• How should production tax credits be treated for property
tax valuation purposes?• Credits are available for 10 years and do have value to a
qualifying buyer, but the benefit is diminishes each year the facility is in service.
• Does this diminishing value warrant an economic obsolescence adjustment during the first ten years, or an accelerated depreciation?
43
• Cash Grants• The grant is a one time receipt of cash and has no value
to a potential buyer other than a reduction in the cost of assets to arrive at FMV.
• The grant is recorded as a reduction in PP&E.• For property tax purposes this reduction in capital cost
has raised some questions.• WY & TX have agreed to the concept of reductions in
capital cost.
Valuation Issues - Government Incentives
44
Valuation issues - Utilization Factors
• The utilization of a Wind or Solar facility is limited, and therefore we must take into account “Utilization Factors” when valuing these assets.
• Typically studies are performed prior to building a facility that will give expected utilization factors. We can then compare these to actual utilization in order to determine if an adjustment is warranted for any given year.
• Also, industry averages of utilization can be used to set a standard for comparison to actuals.
45
Summary of Valuation Adjustments• Renewable Energy and Property Tax Valuation
• With new forms of renewable energy and government incentives we have to realized the importance of potential valuation adjustments.
• Renewable energy is not always economically viable, but necessary to meet carbon reduction requirements.
• It’s important to look at cost and income approaches, taking into account government incentives, in order to determine if there’s a case for economic obsolescence adjustments.
• And finally taking into account utilization factors.
46
Thank You For Your Time
If you have any questions or concerns feel free to contact me. David Wright – 704-382-6125