Abengoa has big plans for Concentrated Solar Power towers in desert

“For Abengoa, it’s very important to be active in the Southwest and continue supporting the efforts to grow renewable energy,” Abengoa executive Santiago Seage told The Desert Sun this week. “Mojave, in that context — being the second flagship project there — clearly is a very important milestone.”

Mojave’s commissioning comes at a tough time for the large-scale solar industry. Development has slowed to a crawl in recent years, hindered in large part by the scheduled expiration of a 30 percent federal tax credit critical to financing large-scale solar projects.

Palen — which would be visible from the southeastern part of Joshua Tree National Park — looked briefly like it would fall victim to the tax credit’s expiration. Regulators approved the project in September, but its developers — Abengoa and BrightSource Energy — withdrew their application two weeks later, in part because they knew the plant wouldn’t be finished in time to qualify for the tax credit.

Abengoa then announced it would pursue the project on its own. Still, Palen’s future is far from a guarantee: Seage said the project is on indefinite hold until there’s more certainty over the future of the federal investment tax credit, which is currently set to expire at the end of 2016.

If Congress simply waits two years and lets the tax credit expire, that could mean Abengoa won’t move forward with Palen until after 2016.

“There should be decisions that give investors certainty over what’s going to happen,” Seage said. “Decisions should be made, even if they’re not the best. It’s better to have decisions, and to know in what context you can work.”

But while uncertainty could stretch into 2017, Abengoa officials see a light at the end of the tunnel — and a particularly bright future for concentrated solar power.

Renewable energy advocates cheered Gov. Jerry Brown’s announcement earlier this month that he wants California to get 50 percent of its electricity from renewable energy by 2030, and Abengoa officials were no different. A 50 percent mandate, Seage predicted, would jumpstart large-scale solar development.

“The fact that California is pushing for a number as high as 50 percent, we think, is very good news,” said Seage, the chief executive of the Abengoa subsidiary that owns the Mojave solar plant.

Any increase to the state’s renewable energy mandate — which is currently 33 percent — could be particularly good news for concentrated solar power.

So far, California has pushed toward 33 percent largely through wind and solar development, but both of those energy sources are intermittent. Traditional solar plants only produce electricity when the sun shines, and traditional wind farms only produce electricity when the wind blows.

That’s where concentrated solar power comes into play. Concentrated solar technology is much more expensive than solar panels and wind turbines, but advocates say it has a major advantage over those technologies: the ability to store energy. More concentrated solar facilities, experts say, would limit the need for fossil fuel-fired power plants to supplement traditional solar and wind.

That’s how Abengoa expects things to play out in California, especially in light of Brown’s recent proposal. Utilities, Seage predicted, will eventually start signing more expensive contracts to buy power from concentrated solar plants because they’ll need those plants to get to 50 percent.

Abengoa, Seage added, is currently developing two or three solar projects in the Southwest, including Palen, which it plans to build with energy storage.

“We expect that going forward, most if not all concentrating solar plants in the Southwest will include storage,” he said. “Clearly, in the context of a 50 percent (renewable energy mandate), storage has a very high value.”

There are two main types of concentrated solar technology. Parabolic trough facilities — like the Mojave plant, which does not have energy storage — use curved mirrors to direct sunlight at thin tubes running throughout the project. Those tubes contain oily fluids that are used to heat water, creating the steam that turns turbines and generates electricity.

“Power tower” projects — like Palen — instead use mirrors to direct sunlight at central towers, where it heats water or another liquid. Most of Abengoa’s future concentrated solar projects, Seage said, will use this technology because it’s cheaper to build energy storage for solar towers than for parabolic troughs.

But power tower technology has come under fire from environmentalists for its propensity to kill birds. The U.S. Fish and Wildlife Service called the Ivanpah solar plant in San Bernardino County — the world’s largest concentrated solar project — a “mega-trap” for birds and insects, although the exact number of bird deaths has been a subject of fiery debate.

Those concerns have generated fierce opposition to Palen, which would be built on a major migratory bird route — the Pacific Flyway. Seage, though, said that in six or seven years of operating two solar towers in Europe, Abengoa “has not seen anything comparable to the numbers that have been shared” for Palen, in terms of bird deaths.