solar energy on a massive scale by: patrick kelly [email protected] [email protected]...
TRANSCRIPT
Solar Energy on a Massive Scale
By: Patrick Kelly
[email protected] College of Law
Energy Law – Spring 2007
Why consider solar energy?• The sun’s energy output is enormous
(3.86e33 ergs/second or 386 billion billion megawatts)
• It has enough hydrogen to burn for millions and probably billions of years
Percentages of Sources of American Energy
0
10
20
30
40
50
60
70
80
90
2000 2001 2002 2003 2004
Fossil Fuels
Non-SolarRenewables
Solar Power
Role of Renewables in 2004
Why not more solar power?
• High capital costs
• Need sunny areas and large spaces
• Hard to transport created electricity
• Not yet commonly used for transportation
• Would require huge changes in infrastructure, policies and behavior
• (1) Smallest/Individual
• (2) Small/Household
• (3) Medium/Community Usage
• (4) Large/Plants
(1) Smallest/Individual Use
(2) Small/Household
(3) Medium/Community Use
(4) Large/Power Plants
Portugal’s Massive Plant
• Spread across nearly 150 acres
• An 11 megawatt plant
• Has 52,000 photovoltaic modules
• Cost about $75 million
• Can provide power to about 8,000 homes
European and Portuguese Goals
• EU currently receives about 6.5% of its power from renewable resources
• A goal of 20% by 2020 has been set
• Portugal's Prime Minister, Jose Socrates, has proclaimed that his country will receive 45% of its power from renewable sources within 3 years.
• Investing $10 billion over next 5 years
Plant in Serpa, Portugal
Concentrating Solar Power
–Dish/engine
–Power Tower
*Parabolic-trough
Dish/Engine
• A dish/engine system uses a mirrored dish• The dish-shaped surface collects and
concentrates the sun's heat onto a receiver, which absorbs the heat and transfers it to fluid within the engine
• The heat causes the fluid to expand against a piston or turbine to produce mechanical power
• The mechanical power is then used to run a generator or alternator to produce electricity
Power Towers
• Use a large field of mirrors to concentrate sunlight onto top of tower, where a receiver sits
• This heats air, water or molten salt flowing through the receiver
• The salt's heat is then used to generate electricity through a conventional generator
• Able to be stored for days before being converted into electricity
Parabolic-trough Systems
• Concentrate the sun's energy through long rectangular, curved (U-shaped) mirrors
• Mirrors are tilted toward the sun, focusing sunlight on a pipe that runs down the center of the trough
• This heats the oil flowing through the pipe, which is then used to boil water
Solar Power Towers
• Solar One
• Solar Two
• Solar Tres
Solar One and Solar Two
• Now defunct power plant based on power tower technology
• Key was using molten salt instead of water or oil as an energy storage medium
• This helped during interruptions of sunlight at nighttime and when clouds passed
History of Plant
• Solar One was completed in 1981 and was operational from 1982 to 1986
• Redesigned, made larger and renamed as Solar Two, the facility reopened in 1995
• Facility was finally decommissioned for good in 1999 and converted into a telescope by the University of California-Davis
• The plants were ambitious and had the ability to produce up to 10 megawatts of power
Solar Tres
• 15 Megawatt project based in Spain
• First commercial project using the Power Tower Technology since Solar One/Solar Two were operational
• Attempting to improve on Solar Two through better and simpler technology
Parabolic Trough Systems
(1) SEGS
(2) Nevada Solar One
SEGS
• SEGS = Solar Electric Generating Stations
• Commissioned between 1984 and 1991
• 9 Projects in the Mojave Desert in Southern California
• “[t]he old SEGS plants have been up and have operated close to flawless”
Truly the Largest
• Many have laid claim to being the “largest solar plant in the world”
• The SEGS cover roughly 1000 acres
• Combined, the plants have a 354 Megawatt capacity
• Two of the individual plants are 80 Megawatt facilities
Drawbacks of the SEGS
• Built more than 16-23 years ago
• Less efficient than today’s technology
• Require a 25% natural gas backup to ensure that the temperature will remain hot enough and steady
SEGS in Mojave Desert
5 of the 9 SEGS Plants
• The Next Generation . . .The Next Generation . . .
Nevada Solar One
An efficient parabolic trough plant
Picture of Crew Working At the Nevada Solar One Site
Nevada Solar One
• At the center, a closed-loop tube will be filled with oil that will be heated by the sun.
• The hot oil will flow around the 400-acre project and into a building where it will turn water into steam
• Steam turns a turbine, which will make electricity
• Nevada Solar One will produce 64 megawatts -- enough to power 40,000 homes in the Las Vegas area during the hottest part of the day
Solargenix President John Myles:
• “Nevada has proven to be very forward thinking in promoting solar and other renewables”
• “The main factor here is that you can get very large blocks of power coming from solar energy in one single location. It is very clearly the lowest cost solar energy that can be produced today.”
Cost of Project
• The total costs of Nevada Solar One estimated between $220 and $250 million
• The power is more expensive than wind power but less expensive than common photovoltaics
• More efficient and cheaper than SEGS, as only 2% natural gas backup is needed
Still, not everyone agrees . . .
Pessimism . . .
• "The industry has some problems to solve," says Paula Mints, associate director and photovoltaic specialist with Navigant Consulting of Palo Alto, Calif.
• "Solar energy has been around 30 years and is still a start-up industry."
In-Fighting Among Alternatives
• “Solar energy is a fraud," said Howard Hayden, "It's being promoted as the solution to problems it can't solve.“
• "Forget hydrogen, forget hydrogen, forget hydrogen" says former CIA Director James Woolsey
• Tad Patzek and David Pimentel claim the return on cullulosic ethanol is negative a greater energy "sink" than corn-based fuel
Optimism . . .
• "If we want to get serious about reducing carbon dioxide emissions and lower our use of fossil fuels, this is a way to quickly address that. I'm very optimistic about this technology."
-- Chuck Kutscher, Principal Engineer and Group Manager of the Thermal Systems Group at the National Renewable Energy Laboratory (NREL)
Real Problems With Other Energy Sources:
• Rising Natural Gas Prices
• Rising Oil Prices and Instability in the Middle East
• Stagnation and possible decrease in hydropower generation due to drought
• Wind is clean, but not a constant source and hard to transport
Annual Photovoltaic Domestic Shipments
Annual Solar Thermal Collector Domestic Shipments
Solar Thermal Collector Average Price
Recent Good News:
• DOE Selects 13 Solar Energy Projects for up to $168 Million in Funding
– Industry led teams to contribute more than 50% of funds for a total of over $357 million over the next 3 years
– http://www.doe.gov/news/4855.htm
For More Information:
• http://www1.eere.energy.gov/solar/csp.html