Can Arizona Become the “Persian Gulf of Solar Energy”?

Michael Giberson

Spanish company Abengoa Solar and Arizona Public Service Company have announced plans to build a large solar powered electric generator, to come online in 2011, but like many such announcements it comes with a couple of public-policy related “ifs”; they’ll build it if they get the necessary approvals from the Arizona utility regulator, and if the U.S. Congress extends the federal solar investment tax credit.

An Associated Press story described the announcement:

PHOENIX, Arizona (AP) — A Spanish company is planning to take 3 square miles of desert southwest of Phoenix and turn them into one of the largest solar power plants in the world.

Abengoa Solar, which has plants in Spain, northern Africa and other parts of the U.S., could begin construction as early as next year on the 280-megawatt plant in Gila Bend — a small, dusty town 50 miles southeast [sic] of Phoenix.

The company said Thursday it could be producing solar energy by 2011.

Abengoa would build, own and operate the $1 billion plant, named the Solana Generating Station.

Solana will be enough to supply up to 70,000 homes at full capacity.

It won’t be Abengoa’s first solar project in Arizona. Since 1999 the company has operated a 17,000 square foot solar powered hot water system serving a federal prison complex. The system is said to have reduced overall electric consumption at the facility by about 10 percent.

The AP story quoted Arizona governor Janet Napolitano as saying, “There is no reason that Arizona should not be the Persian Gulf of solar energy.”

It is always tempting to “do the math” when a politician makes such, um, enthusiastic claims.

Well, why not? Let’s see: Three square miles yields a 280 MW capacity plant. Using the 70,000 homes number, a little calculation gives a 38 percent capacity factor for the plant, so that implies the plant will produce about 932,000 MWh per year. If Arizona is going to become the “Persian Gulf” then they must be a net exporter of solar, meaning they first serve all the state’s own consumers and have power left over to export. If all of the state’s electric power needs were generated using similar technologies and assuming constant economies of scale, it would take about 236 square miles (or about 1.2 percent of the land mass in the state) to accommodate the necessary solar power plants.

So 236 square miles of Arizona would, on the assumptions listed, get self-sufficiency from solar. Presumably a “Persian Gulf” would be a big exporter of power, not just self sufficient. Here the calculations rapidly get crazy (i.e., over 36,000 square miles of land), depending on just what you think a “Persian Gulf of solar energy” means, and that doesn’t include the land needed for additional transmission lines.

Nowhere in the article does it say just how expensive the new solar plant will be, but given that the project hinges on regulatory approvals and continuation of the federal solar investment tax credit, we can assume it isn’t yet competitive with other commercial electric generation technologies.

UPDATE: See also this related post: How can Arizona become a solar power exporter if it opposes building interstate power lines?