Ausra goes for a gigawatt

Ausra, a solar thermal specialist from Australia, on Thursday said it will try to build solar power plants in the U.S. over the next seven years that collectively will generate a gigawatt worth of power. Three hundred megawatts worth of that capacity is already committed to FPL Group, a utility concentrated in Florida, according to Ausra.

Another likely customer is Pacific Gas & Electric. The California utility has committed to signing contracts for a gigawatt worth of solar thermal power over the next five years. PG&E is talking to a number of solar thermal companies about this, including Ausra.

These plants, along with the other solar power plants in the planning stages, will greatly expand the footprint for solar thermal power. Solar thermal plants concentrate sunlight onto mirrors to collect heat, and then use the heat to create steam or gas from an enclosed liquid. The pressure from the gas then turns a turbine to create electricity.

The biggest solar plant in the world right now, in California's Mojave desert, can generate around 354 megawatts. It was built 22 years ago. Acciona Solar Power earlier this year inaugurated the first solar thermal plant in over a decade anywhere in the world. It sits outside of Las Vegas.

Large plants--like the 300 megawatt plant Ausra will build for FPL--could also help bring down the cost. Right now, solar thermal power costs more than regular power from gas or coal-burning plants. But scientists, venture capitalists and analysts have said that solar thermal plants can be comparable in cost if built large enough. The rough estimate is that a 500 megawatt solar plant, or a couple of 300 megawatt solar plants built close to each other, could be comparable with traditional electricity. The cost projections, however, all vary according to environmental conditions, proximity of large cities to the power plant and construction costs.

Utility company Southern California Edison is erecting a 500-megawatt plant scheduled to open in 2009.

Large conventional power plants can often put out around 500 megawatts.

Besides building large power plants, Ausra, which recently raised $40 million, says it can cut the costs in other ways. Unlike a lot of solar thermal companies, Ausra doesn't used curved mirrors to collect sun or oil to fill its heat collectors. Instead, it uses cheaper flat mirrors and water.

Earlier this month, Ausra CEO Peter Le Lievre told an audience at the Going Green conference that a solar thermal plant in the desert measuring 92 miles by 92 miles built with his company's technology could provide all of the electricity in the country.

"We are more than two times more efficient when it comes to land," he said. "We are at 10 cents a kilowatt hour today," he said. With mass manufacturing, we will fall below gas (natural gas plants) and beat coal."

The company is currently trying to get a permit to build a 175-megawatt plant in California that would take up a square mile.

Of course, this could all change. Utilities are buying solar thermal because of state mandates. Ausra also faces several competitors.

[ds_gray]

What Happens When...

It gets dark outside? Building these immense solar plants is fine, but are they planning on building a 500-megawatt lead-acid battery, too?

On the surface, it seems wasteful to invest capital and build a power plant of that size and capacity that can only work when its sunny.

Besides, if they can't at least get one-point-twenty-one gigawatts out of it...not interested.

[enovikoff]

myopia

In California, at least, electrical demand tracks solar output, since air conditioning uses a major portion of electrical power on sunny days. However, assuming that solar is not usable because of its duty cycle is flawed in other ways too: every watt generated with renewable sources saves on atmospheric carbon output. It's possible to find something "wrong" with every renewable energy source, but you'll have to stand on your roof to shout out that opinion once the oceans rise and flood your city.

Finally, there are a number of effective power storage alternatives that have been used to distribute peak load and could just as effectively be used to distribute peak generating capacity: pumped hydroelectric storage and underground compressed air storage for example.

[michael kanellos]

To answer your questoins

what happens when it gets dark? You store the heat in salt or other substances and make electricity later. It's a very Roman Empire technology.

also, the sun shines a lot. nevada solar one gets well over 300 days of sun a year.

[bayareaduck]

do your homework...or at least a google search

of course these plants can store energy and produce when the sun is not out with storage that does not require traditional, inefficient battery technology. that is right this provides a completely green footprint for power generation and storage and can use existing turbines so even those can be reused. no harmful chemical processes and residue or power consumption for complex manufacturing of PV solar panels.

thank goodness google makes it almost effortless to find information to become educated on a topic quickly. too bad so many people are too lazy to get informed and fell compelled to spew such ignorant misinformation.

[chrisp5683]

Solar thermal plants such as this one are used to boil water (just like coal or nat gas or nuclear plants), which turns turbines and produces electricity 24/7, even when it's cloudy or dark. What you are thinking of are photovoltaic cells, which only produce electricity when it's light outside.

If it's true that current costs are $0.10/kWh to produce (and only likely to go down from here), this could be one of the BEST ways to energy independence

[maeckg]

Energy storage

Although solar is great for peak demand, all solar energy installations can rely on diverse energy storage methods to buffer for off-peak use.
Solar thermal has advantage to use molten salt or hot water/oils to store the heat directly. Batteries, flywheels, super compressed air, hydrogen, higher water reservoir are some of the choices for both solar PV and thermal. Many traditional power plants use the same storage methods to buffer the loads.
The power grid in US is overbuilt for the base load, usually provided by coal, nat gas, nuclear plants that need to run 24/7, but the unpredictable peak loads due to air conditioning use on hot days causes issues with the grid.

Utilities have to quick start special generators that are not as efficient and may use expensive fuels and shift power around the grid to provide for a few hours of peak demand. Like the one comment says, solar power works best right when needed.

Solar thermal plants can be used just like the peak load generators by the utilities while having the advantage of reducing overall emissions and fuel costs. Definately worth the investment. I think some solar thermal plants can be designed to work close by the customers since are very clean and silent.
Smaller ones could be implemented at large shopping malls, apartment or office complexes and factories in the Southwest by using a covered parking lot for the mirrors. It would mean a lot of energy savings by thousands of cars not being so hot as they would when parked in the sun.

bluft

[rustycat101]

I am under the impression AUSRA is a USA company from silicon valley, Ca. They have just finished a project in Nevada, USA, and are developing otheer projects in the USA.
Let me know if my info is incorrect.