World's largest solar installation to use Stirling engine technology

Free Energy News ^ | Aug 05 | Sterling D. Allan

[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.

[sitetest]

Dear Arkie2,

LOL!!!

Not ALL of Maryland!! There's a lot of pretty countryside and rural communities here. Even REPUBLICANS (19 of 24 jurisdictions voted for Mr. Bush in 2004 - the problem is that the three largest jurisdictions, comprising nearly half the state's population, went strongly for Mr. Kerry) live here!

How about we take all the property, building, land, structures of all the leftist think tanks, lobbies, and other special interest organizations that reside in Maryland, level everything, and erect solar panels and stirling engines??

Although, I gotta warn ya, we just don't get as much sun as the American Southwest, so we're not going to generate electricity at the same rate per given unit of area.

Still, at least we'll get SOME productive value from the land. ;-)


sitetest

[sitetest]

"Don't know about the sandstorm but the hail storm would be about 7 million years of bad luck by my calculations."

ROTFLMAO!!

[Arkie2]

I like your compromise and even if it generated 0 electricity it's still a good idea!

[G Larry]

500 MW Bull$hit!

VuGraph engineering & marketing.
This will not produce 50 MW in the next 12 years and costs will have tripled.

Use the time, money, and realestate for nuclear power plants!
In 1980 I outlined a 25 year plan to grow and mature nuclear energy as part of a Masters project.
That's what we needed then, and that's what we need now.

[Arkie2]

I think you'll find the new energy bill paves the way for new nuclear plants (finally) and according to Bush we should see some results in that area by 2010. My primary interest in this article wasn't even the solar aspect but the use of stirling engines as an enabling technology.

[sitetest]

Dear G Larry,

I'm on board with nukes, too.

I don't live too far from Calvert Cliffs in Southern Maryland.


sitetest

[G Larry]

Yup!
I just read and comment on the post regarding the Nuclear provisions of the bill.
Noted that the licensing process must make them "litigation proof".

[ThePythonicCow]

From http://ffden-2.phys.uaf.edu/212.web.stuff/Lichtenberger%20and%20Jenson/Collin%20Lich%20&%20Eric%20Jense%20Folder/how.html

---

How Sterling Engines Work

---

    This page illustrates two basic designs of sterling engines, the first is the simplest form, it is a basic displacement engine the second works on the same principles but it is a little more intricate and is known as a two cylinder engine.

THE DISPLACEMENT ENGINE:
  Figure 1

 

    In the displacement engine there are two pistons.  The smaller piston shown in the illustration is the power piston.  All of the power for this model is provided by the power piston.  The second larger piston is the displacer piston.  It's function is to move the air between the hot and the cold sides of the air compartment.  It provides no power at all.  The power piston for this model should be 90 degrees out of phase from the displacer piston.  This model has four simple steps.  Begining at the top of the illustration, the first step is heating.  The heating is caused by the movement of the displacer piston so that most of the gas is on the hot side.  The temperature of the gas subsequently increases, causing an increase in pressure.  Because of this increase in pressure there is an expansion of the gas causing the power piston to rise.  Then, due to the 90 degree phase shift between the two pistons, the displacer piston is moved, resulting in the cooling of the gas.  But when the gas is cooled, the pressure decreases, causing a contraction in the gas, thereby pulling the power piston back down.  Then once again, due to the 90 degree phase shift, the displacer piston follows causing the gas to shift to the hot side of the chamber.  The temperature of the gas then increases, and we are back to our first step.  This is the most basic model of the stirling engine.

---

 

THE TWO CYLINDER ENGINE:

  Figure 2
 

    The two piston model is slightly more complex.  There are still two pistons, and they are still 90 degrees out of phase from one another.  However, in this model power is supplied by both pistons, and the displacement of the gas is caused by both as well.  Yet it does follow the same basic process.  Once agian, starting from the top of the illustration, the first step is the heating of the gas in the chamber.  The flywheel is turning, and thus the cold piston moves up, and the hot piston moves down.  This causes the gas to flow to the hot side.  This then causes an increase in the temperature of the gas.  The gas therefore expands, pushing both pistons downward.  At this point the inertia of the flywheel causes it to continue rotating which in turn raises the hot piston and pulls the cold piston downward.  The gas is then pulled to the cold side of the chamber, and the temperature of the gas is decreased.  But this decrease in temperature causes the gas to contract, and therefore pulls both pistons upwards.  Then, once again, the inertia of the flywheel pulls the hot piston down and pushes the cold piston up.  Thus the gas flows to the hot side of the chamber and is heated, leaving us where we began.
 
 

[Arkie2]

What kind of rpm and horsepower can they generate?

[rawhide]

"However, this isn't the first commercial application of Stirling engine technology. For instance, Swedish submarines use Stirling engines for propulsion.

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. "

Amazing to have a submarine using this. Imagine a submarine riding on top of the ocean all day just to catch the rays of the sun.

[Arkie2]

LOL! OK, I get the joke but if you are interested in stirlings in subs check out the link

http://www.kockums.se/Submarines/aipstirling.html

[RightWhale]

There would be no energy crisis now, no reliance on the Arab oil, no Alqaida, no problem with Iran, Iran, if this technology had been started 1/4 century ago. Instead some greenie luddite concern has killed all public discussion, and the same with nuclear power.

[Lx]

There's a company that has a cool Stirling demo engine. You put it on top of a cup of hot water and start it going and it just cruises along. Alas, I have no link.

[Oatka]

[Sterling Engine]
"Perhaps $60+/bbl oil will bring a new surge in American innovation."

Ding, ding, ding!!! We have a winner!!!

I'll bet the same thing would happen on farms if the illegals were eliminated. All kinds of wonder machines would appear, FAST.

[Arkie2]

Link is here.

http://www.signonsandiego.com/news/business/20040601-9999-1b1stirling.html

[Walkingfeather]

because the materials for the seals and such took that long to perfect. You could build small ones but larger ones were the challenge. I know dean kamen was working on perfecting it.

[Arkie2]

I saw Kamen mentioned in an article on stirling engines saying he was considering adding it to his segway to give it extended range.

[Balding_Eagle]

There are still two pistons, and they are still 90 degrees out of phase from one another.

Wouldn't having them 180 degrees from each other produce a smoother power output?