Slashdot Mirror
Largest US Power Storing Solar Array Goes Live
Lucas123 writes "A solar power array that covers three square miles with 3,200 mirrored parabolic collectors went live this week, creating enough energy to power 70,000 homes in Arizona. The Solana Solar Power Plant, located 70 miles southwest of Phoenix, was built at a cost of $2 billion, and financed in large part by a U.S. Department of Energy loan guarantee. The array is the world's largest parabolic trough plant, meaning it uses parabolic shaped mirrors mounted on moving structures that track the sun and concentrate its heat. A first: a thermal energy storage system at the plant can provide electricity for six hours without the concurrent use of the solar field. Because it can store electricity, the plant can continue to provide power during the night and inclement weather."
The plant doesn't really store electricity. It can however, store heated salts that can be used to generate electricity well after sunset.
Covering your home in solar panels in Arizona can save you about $100/mo on your power bill, which for a single-family-residence runs about $200 in the winter and about $400 in the summer.
Those panels aren't free. They can take 10+ years to pay for themselves.
If it takes Solana 10 years to break even, that's $3,000 per year, per home served, or on par with their current power bills, and doesn't involve burning any fossils.
Nighttime lasts longer than that.
Or more likely, they did some demand modeling and found some value that made the economic sense?
Electricity demand follows a predictable pattern, with the lowest demand between 10pm and 7am. If surplus power (to storage) were to transition from positive to negative in the early evening, then 6 hours of stored capacity might work out pretty well.
Technically nothing stores electricity except for super-cooled superconductors. Batteries "store electricity" in the form of chemical energy and even capacitors only "store electricity" as two charged plates. But I think we all know what they meant, that it was storing the potential for electricity.
We've already got one fairly awesome nuclear plant -- located fairly close to these solar arrays, by the way -- but I wonder if the $5300/hW figure includes long-term storage and disposal costs.
I suppose salt tanks might, but there's also the pleasure of knowing that (a) your solar system can't go into meltdown, and (b) you can destroy people with your laser array.
PV is only cheaper per watt over lifetime at small sizes. There is a crossover point where thermal solutions make more sense. With PV when you double the scale you get double the output. With thermal you get more than double the output when you double the scale.
PV is popular because it can be done at small scales and has been in continuous use since the 1970s. Solar thermal requires great big turbines etc, so a large capital cost, before you can get one watt out of the things so it is very unpopular with those who don't wish to invest (just about everyone in charge of budgets).
China 2007:
Tianwan Nuclear Power Plant
$3.3 Billion for 2,120 MW
$1.56 Million/MW
US 2013:
Solana Solar Power Plant
$2 Billion for 280 MW
$7.1 Million/MW
And we wonder why we keep having to borrow money from them?!
-- "Government is the great fiction through which everybody endeavors to live at the expense of everybody else."
Do you think they vent the steam to the atmosphere? Or do you think they might put it in a closed loop so they can reuse the water?
That was the turning point of my life--I went from negative zero to positive zero.
No matter what the power plant... No matter how clean and low-impact it is, some moron ALWAYS has to find something stupid to bitch about.
Are you suggesting that a nuclear power plant would be a scenic tourist attraction, right at home inside Yellowstone? How about a coal power plant, along with the huge open-pit mine where the coal comes from? Or maybe some nice tar sands right outside your back yard?
If you don't like the fact that electricity generation is going to use some land, then cut the power lines coming into your house and live in the nice, scenic, non-blighted dark and cold.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant