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Ask and ye shall receive:
Posted on 08/13/2005 3:42:35 AM PDT by Arkie2
ROSEMEAD, CA, USA -- A Stirling engine is commonly referred to as an "external combustion engine" in contrast to the "internal combustion engines" found in most vehicles. Combine a Stirling engine with solar as the source of heat, and you have a highly efficient means of converting solar power into usable energy.
That is what Stirling Energy Systems has been perfecting for the past 20 years.
On Aug. 8, 2005, President Bush toured the DOE's National Solar Thermal Test Facility at the Sandia National Laboratories complex, situated on Kirtland Air Force Base in Albuquerque, N.M., where he signed the energy bill.
Now they are ready to go big-time, with an agreement signed Tuesday with Edison International (NYSE:EIX) a subsidiary of Southern California Edison (SCE), the nation's leading purchaser of renewable energy.
On Tuesday they announced an agreement that could result in construction of a massive, 4,500-acre solar generating station in Southern California. This comes to around seven square miles, with a perimeter of nearly 30 miles. The completed power station would be the world's largest solar facility, capable of producing more electricity than all other currently-operating U.S. solar projects combined.
This signing was a day after President George W. Bush visited their Sandia National Laboratories installation where they have six prototypes in operation, having chosen this location as his backdrop for the signing of the Energy bill.
Signed Tuesday, the 20-year power purchase agreement, which is subject to California Public Utilities Commission approval, calls for development of a 500-megawatt (MW) solar project 70 miles northeast of Los Angeles using innovative Stirling-engine/solar-dish technology. This is enough power to run approximately half a million homes.
According to the California Energy Commission, there are 966 power plants in California that generate more than 0.1 MW. Of those, a 500 MW plant would be in the top 3% for size.
The agreement includes an option to expand the project to 850 MW.
Initially, Stirling would build a one-MW test facility using 40 of the company’s 37-foot-diameter dish assemblies. (Each dish generates 25 kilowatts.) This phase is slated to be completed in the first quarter of 2007. One of the 40-unit arrays capable of a 1 MW output, will be dubbed a "solar power group" and will be the basis of modular calculations for future installations.
Subsequently, the 20,000-dish array is to be constructed near Victorville, California, during a four-year period, starting in early 2008. If Edison opts for the additional 350 MW installation, that will take two more years, and will bring the total number of panels to 34,000.
“At a time of rising fossil-fuel costs and increased concern about greenhouse-gas emissions, the Stirling project would provide enough clean power to serve 278,000 homes for an entire year,” said SCE Chairman John Bryson. “Edison is committed to facilitating development of new, environmentally sensitive, renewable energy technologies to meet the growing demand for electricity here and throughout the U.S.”
“We are especially pleased about the financial benefits of this agreement for our customers and the state,” said Alan Fohrer, SCE chief executive officer. “The contract requires no state subsidy and provides favorable pricing for ratepayers because tests have shown the Stirling dish technology can produce electricity at significantly lower costs than other solar technologies.”
Gil Alexander, spokesperson for Southern California Edison said, "We operate in a competitive marketplace. While [for confidentiality reasons] we cannot give out precise dollar amounts for how much these installations will cost, we believe the final agreement is very beneficial to our customers. We do not need any subsidies to make this work."
Pioneering Stirling-solar to be Commercially Viable
Although Stirling dish technology has been successfully tested for 20 years, the SCE-Stirling project represents its first major application in the commercial electricity-generation field. Experimental models of the Stirling dish technology have undergone more than 26,000 hours of successful solar operation. A six-dish model Stirling power project is currently operating at the Sandia National Laboratories in Albuquerque, New Mexico.
However, this isn't the first commercial application of Stirling engine technology. For instance, Swedish submarines use Stirling engines for propulsion. (ref)
How It Works
The Stirling dish technology converts thermal energy to electricity by using a mirror array to focus the sun’s rays on the receiver end of a Stirling engine. Each panel tracks azimuth and elevation to keep the sun’s rays focused at greatest intensity possible.
The internal side of the receiver then heats hydrogen gas which expands. The pressure created by the expanding gas drives a piston, crankshaft, and drive-shaft assembly much like those found in internal combustion engines but without igniting the gas. The drive shaft turns a small electricity generator. The entire energy-conversion process takes place within a canister the size of an oil barrel. The process requires no water and the engine is emission-free.
Comparison to Other Solar Technologies
Tests conducted by SCE and the Sandia National Laboratories have shown that the Stirling dish technology is almost twice as efficient as other solar technologies. These include parabolic troughs which use the sun’s heat to create steam that drives turbines similar to those found in conventional power plants, and photovoltaic cells which convert sunlight directly into electricity by means of semiconducting materials like those found in computer chips.
Additional Applications
While the number of potential applications for this technology is huge, in the near term Stirling Energy Systems will be keeping their focus on these utility installations.
GREAT News!...but where's Enron?
Because they are relatively complex and unreliable. The Stirling engine used in this application has been under development for at least 30 years (I have a book about it that I bought about ten years ago). The new design uses magnetic bearings and a whole lot of other high-tech stuff that just didn't previously exist. In the book, the working fluid was helium. I wonder wy they switched to hydrogen???
Yes and no. Solar power satellite in earth orbit, or on the moon simply aren't profitable at today's launch and electricity prices. What is needed is an NSO SPS-statite-receiving station system. An SPS is placed in a near solar orbit of (preferrably) around 10 million km from the sun. The solar energy is converted to microwave which is beamed to a statite in polar orbit. The polar statite in turn beams the energy down to receiving stations along the hemisphere.
The increased solar flux makes the entire venture profitable, even if electricity is only sold for 1/10th of a cent/kWh (IIRC).
About two-thirds of our crude oil consumption becomes transportation fuel; over 95% of our transportation fuel comes from crude oil. Gasoline, or related aliphatic hydrocarbons, represent the most efficient, convenient, least hazardous way to distribute, carry, and store hydrogen for use as fuel. In order to store the same number of hydrogen atoms in the same space as compressed gas, a pressure of nearly 20,000 PSI is required, about TEN TIMES what commercial tanks can contain. The fuel of the future might be hydrogen, but the hydrogen will be attached to carbon, and we will still call it gasoline. And when we don't have enough crude oil to make it from, we will use other raw materials.
Aviation has no viable alternative fuel, but our rail system could be converted to run off the electric grid with relative ease, which would save a significant amount amount of fuel. The additional electricity would be just small increase in total generating capacity. Yes, we would need to distribute it along the mainline tracks, but every existing locomotive ALREADY is electric powered - they just generate their own electricity with an internal diesel generator.
Eh? The leftists ARE in control where it counts, the bureaucracy. They write the rules, and control education. Two generations of nanny state control, free hand outs and dumbed down education have really put this country on the ropes.
Equal access to energy would be great. Enforced equality is the current target. "To each according to their needs" implies that someone judges individual needs. No thanks. As far as access goes, just try digging something out of the ground, or burning something, and you'll be swamped with red tape.
There must be a better way. By and large the methods of energy conversion were established in the last century because they are governed by physics. What is at hand now are revolutions in computer control and materials science. Hopefully someone will have a "Eureka!" moment that will make the old new again and change the playing field.
Gotta go. No time to sit in front of the computer all day.
From the cobwebs of my memory, a ~10 foot diameter solar "furnace" can only boil a cup of water every hour.
Throw in clouds, volcanic ash, angle of the Sun through the atmosphere, evenings,...
Any way, perhaps something other than water powering a turbine?
Agreed. Gasoline and diesel fuel (or components thereof) are nearly perfect vehicles for transporting energy. The whole H2 parade misses a large point in that the conversion of C into CO2 yields enormous energy.
Must... separate... self.. from.. computer.
Life is calling. Be back later.
"On Tuesday they announced an agreement that could result in construction of a massive, 4,500-acre solar generating station in Southern California. This comes to around seven square miles, with a perimeter of nearly 30 miles."
That seems like a lot of land to generate 500MW while the sun's up.
I've seen plans that the Germans designed a space station back in the 1920's that would have used a solar driven Stirling engine as a power source. I have a book, "The How and Why of Nechancial Movements" that Popular Science put out about 1968 or so that mentioned the Stering engine in detail and how it could be used to run a quiet lawnmower, a boat, a powersource for space stations and even as a source for poor nations with little resources.
" This is the last unexploited technology available for use."
Guess we'ed better shut down the patent office again.
There's a lot of virtually useless land in the Southwest that could be profitably put to work in this manner. It does eat up a lot of real estate for these type installations but there's plenty of it to go around and it has plenty of sunshine. It's called desert.
I can't wait for the greens to start their objections though. Surely there's some toad or lizard that will be affected by all those solar power arrays.
I guess your comment about new materials and computer controls is the real answer to why stirling engines are seeing more use. Someone decided to try and use the old technology with updated processes and materials.
The stirling engine is being used very effectively in a new type of coastal patrol submarine that is so quiet and effective the US navy is very very concerned it may fall into the wrong hands, like Iran.
Dear Arkie2,
Yeah. A little back-of-the-envelope shows that for, say, the amount of territory equal to about the size of my own state, Maryland (or maybe double that), we can probably generate about 20% of the electricity used in homes.
It's certainly not a panacea, but it sure helps. As well, in that creating new sources of electicity generation can power things like hydrogen fuel cells and the like for transportation needs, in the long term, this technology could have a real, if somewhat limited, impact on our use of oil.
sitetest
No, don't say it! Arrgh, I-can't-stop-myself! OK, I can't resist!
Maybe the best use for Maryland and Massachussets etc might be as a giant solar power generating station.
DUCK!
What does one 50 mph sand storm or one 1" hail storm do to this array of mirrors?
~~~~~~~~~~~~~~~~~
Ask and ye shall receive:
Don't know about the sandstorm but the hail storm would be about 7 million years of bad luck by my calculations.
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