Spain plugs in largest solar-tower power plant

At Abengoa Solar's facility in Spain, mirrors heat a liquid in a tower, on right, that produces steam to make up to 20 megawatts of electricity.

(Credit: Abengoa)

Abengoa Solar of Spain on Monday reported successful tests of its second solar tower in operation, in which the sun's heat is used to make electricity.

The 531-foot solar tower, located near Seville, Spain, features a number of improvements on the first design and has exceeded the anticipated output. Called PS20, the installation is the largest in the world with a capacity of 20 megawatts, enough electricity to supply 10,000 homes, according to the company.

A solar tower configuration uses a field of heliostats, or mirrors, to concentrate sunlight onto a receiver held in the tower. The heat creates steam which turns a turbine to make electricity. The PS20 project has 1,255 of these heliostats, with each heliostat having a surface area of 1,291 square feet.

Concentrating solar thermal technology has been used in desert areas in Spain and the southwest U.S. for decades and is seeing a resurgence as utilities seek out cost-effective solar power.

The traditional solar concentrating power uses rows of mirrored troughs that follow the sun over the course of the day.

Solar tower technology is considered the successor technology to mirrored troughs and is being pursued by a number of solar companies, including renewable energy powerhouse Abengoa and California start-ups BrightSource Energy and eSolar.

Abengoa Solar said that this installation improved on the first solar tower in Spain with better control systems and solar thermal energy storage system.

[Angmarr]

Solar is the best form of alternative energy, through not completely practical yet. Hope some of the US lawmaker see this soon.

p.s this is my final goal after graduating - to go into to solar!

[The1egend]

Is that the focal point above the tower that you can actually SEE in the picture? If so, why isn't it on the tower? Just above the lower tower in the pic there is that white whispy thing, if you don't know what I'm referring to.

[myles taylor]

I'm not sure what that is, but I'm pretty sure it's no the focal point. You wouldn't be able to see the focal point from this angle.

[GKrynen]

Yes it is a focal point but the camera captures it at an angle to where it actually is, like a reflection (ghost image). By the way that flare seems to be from the smallest tower, yes there are three in that picture. These are older designs based on technology like Solar One out in Daggett, CA. Currently in Lancaster, CA we are getting a much smaller test unit based on smaller mirrors and shorter towers that cost less to install and the units are supposed to have lower operating costs.

[wth31]

Yes. They can move the focal point off the collection tower and place it in the air above and beyond the collection tower. Useful for working on collection tower or on a collection of heliostats or just reducing output to the collection tower. A show recently on Discovery Science Channel showed the focus moved off the tower for some heliostats and it looked exactly like what is in the photo above.

[myles taylor]

Yes! Solar energy is the most abundant and clean energy source out there. There is no energy shortage and there need not be. We just have to learn to capture the sun's energy more effectively. Necessity is the mother in invention. We would do it if we felt that we had to. Wind resources and solar resources could easily replace all our power plants if we put a little effort into it.

[MagiMamoru]

That monstrosity can only produce 20 MW? What a waste of space. The solar plant in Navada has a better production rate of 64MW.

My personal preference is the Stirling Engine System.

[martin1212]

I'm all for solar, but to give an idea of the scale of what is needed, you would need to build one of these plants every 2 days in the US just to keep up with the increasing power demands due to population growth alone, never mind meeting existing demand.

[Joe Real]

I agree with MagiMamoru. There is tremendous wasted space on that solar power plant. It shouldn't matter if land isn't a premium. It is like 75% of the land area within the facility is not catching any sunlight. The real efficiency of that solar power plant could be very low, something like in the 9% range.

Real Efficiency = total power generated / total sunlight power falling on entire area of facility

If the land was bought at a premium and it is amortized, I think the finance charges on the land alone could be greater than the price of the electricity produced. If the land is practically free, then it would only be the finance charges of building the solar power plant to compare against the electricity produced. When both the land and the power plant are counted for capitalization, the total finance charges should be compared with the price of electricity produced.

[Azger]

> I'm all for solar, but to give an idea of the scale of what is needed, you would need to build one of these plants every 2 days in the US just to keep up with the increasing power demands due to population growth alone, never mind meeting existing demand.

You could build one a day and Americans would still waste half the energy that each produces.

As for the Nevada plant, it was built by a Spanish corporation (Acciona) and is 95% owned by a Spanish Corporation (Solargenix).

[spleenbiter2112]

Solar can only be a regional solution, it would only work in those climates with a majority of cloudless days. Most of the demand for power does not come from those regions. Try again.