Is an acre of desert really worth $14,700?
From http://www.tucsoncitizen.com/ss/related/77596
Abengoa Solar Inc., a Spanish technology company that has several smaller solar-thermal projects in Spain, North Africa and the United States, will build and run the Solana Generating Station.
Solana will use 2,700 “troughs” of mirrors lined up across former alfalfa farmland, focusing sunlight on tubes in the middle of the troughs.
The tubes will be filled with a petroleum-based chemical that will heat up to 735 degrees, and transfer their heat to water, making steam and spinning turbines in two 140-megawatt generators. The petroleum liquid is reused in the tubes, not burned.
The plant also will use molten salt to store heat and continue generating electricity for as long as six hours after the sun sets. That’s key in Arizona, where residents use the most electricity between 5 and 6 p.m., when the sun is low in the sky and common solar panels struggle to generate electricity.
To meet peak demand, utilities buy expensive energy from natural-gas plants.
“This will displace our most expensive form of generation,” Brandt said.
However, solar plants cost more than coal, nuclear or even the most efficient natural-gas plants for the amount of electricity they generate.
APS will pay about 14 cents per kilowatt-hour, compared with about 10 cents per kilowatt-hour from natural-gas plants at peak demand.
The premium is worth it because coal and natural-gas prices are unpredictable, and emissions from those plants likely someday will be taxed for their contributions to global climate change, Brandt said. That makes predictable solar prices attractive.
Looks like it was irrigated alfalfa farmland.