Solar Energy

Solana Solar Plant Produces Less Energy Than Advertised, But That's Expected, Says APS

The $2 billion Solana concentrated solar plant in the desert near Gila Bend is off to a slow start, producing less electricity than it might in the future.

Now in operation for slightly more than one year, Solana has delivered about two-thirds of the annual amount of electricity expected to be received in the future, say officials with Arizona Public Service.

Utility officials and the plant's builder say they anticipated it would take time for the plant to work out initial problems.

See also: -Solana: 10 Facts You Didn't Know About the Concentrated Solar Power Plant Near Gila Bend

The 280-megawatt plant, built by Spain's Abengoa company with the help of U.S. grants and loan guarantees, has a 30-year power-purchase agreement with APS. It has 900,000 mirrors that focus sunlight on pipes containing a molten substance, which heats up to power two 140-megawatt steam turbines. Because the mixture retains heat for a while, the plant continues to produce electricity for several hours after the sun goes down, unlike photovoltaic solar panels.

News reports and government documents based on statements from Abengoa indicated previously that the plant is supposed to pump out roughly 900,000 megawatt-hours of electricity per year.

However, now that data from the first year of operation is in, officials say the plant won't be hitting 900,000 megawatt-hours a year until it's "mature."

APS pays only for the electricity actually delivered, so ratepayers haven't been impacted by the first-year shortfall.

Although the plant "has not produced up to the fully expected annual production level over that time period," neither APS nor Abengoa expected it to, says Brad Albert, APS' general manager of resource management.

Earlier this week, the California Energy Commission announced that the Ivanpah solar plant in the Mohave Desert, operated by NRG Energy and owned by Solar Partners, has only delivered about half the electricity expected in its first few months of operation, and that its natural-gas backup system was being overused. The agency said in a statement to the news media that "factors such as clouds, jet contrails and weather have had a greater impact on the plant than the owners anticipated." NRG officials also blamed start-up problems. Ivanpah is a type of concentrated solar plant, but it uses a different scheme than Solana to generate electricity, focusing the sun's rays on a central tower to create heat for steam turbines.

Solana hasn't had similar problems with contrails or clouds, Abengoa and APS representatives say.

APS anticipated that the Solana solar plant would have a "shakedown" period with equipment issues and "initial bugs," Albert says.

Given that the utility expected less than "mature" output in the first year, APS considers the plant to be a success already.

Its primary selling point of energy storage -- that is, the ability to keep producing power in the evening, during peak demand times -- "has worked like a charm," Albert says.

Abengoa, in a statement released to New Times, says that the plant so far has performed "beyond the expectations of its developer."

While covering the plant's many good points, the statement acknowledges that "Abengoa continues to tune the project," adding that, "It is to be expected that a project of this size and complexity will have a certain initial ramp-up period followed by many years of successful operations."

So, check back for next year's numbers and expect to see improvement, in other words. The company touts its extensive experience, implying the lower power output is no cause for concern: "Abengoa itself operates 16 plants using [technology similar to Solana's], most of which exceed expected production."

Got a tip? Send it to: Ray Stern.

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Ray Stern has worked as a newspaper reporter in Arizona for more than two decades. He's won numerous awards for his reporting, including the Arizona Press Club's Don Bolles Award for Investigative Journalism.