February 14, 2010

Tree deal revives Southwest desert solar plan

Developer NextEra's proposal to cut down hundreds of thirsty tamarisk trees may provide a blueprint for resolving similar environmental disputes over solar farms in the desert.

A rendering shows where a solar power plant proposed by NextEra Energy would be installed near California City, a desert community east of Bakersfield. (California Energy Commission / February 11, 2010)

By Todd Woody
Los Angeles Times


A developer who proposes to cut down hundreds of trees to make way for a massive project could expect to provoke a fair amount of environmental outrage.

Not in California City. Officials in this sprawling desert community east of Bakersfield are thrilled at NextEra Energy's move to break out the chain saws.

The firm, a subsidiary of utility giant FPL Group, is seeking to build a solar power plant in the area that would consume a large amount of water. The trees are tamarisks, a water-hungry invasive species, and removing them could help recharge the aquifer in this arid region.

"The water that normally would go into the tamarisk will go down into the basin -- it's a big environmental win," said Michael Bevins, California City's public works director.

The tree deal is just one way that what threatened to become another intractable fight over the environmental effect of desert solar power plants is turning into a blueprint for the resolution of similar disputes.

Proposals to build dozens of solar farms on hundreds of thousands of acres in the desert Southwest have split the environmental movement and divided local communities. For solar developers and some green groups, the projects are desperately needed in the fight against climate change; others see them as a threat to unique and fragile ecosystems.

Water has become a particular flash point. Solar thermal power plants use mirrors to heat liquids to create steam that drives an electricity-generating turbine. The steam must be condensed and the hot water cooled for reuse. The cheapest and most efficient way to do that is wet cooling, which lets the heat evaporate but requires the constant replacement of water.

By last fall, NextEra's 250-megawatt Beacon Solar Energy Project was mired in a war over water. The company wanted to tap more than half a billion gallons a year from freshwater wells to cool the solar farm to be built on former farmland.

State policy prohibits the use of drinking water for power plant cooling, and local residents lined up at public hearings to express concern that the solar farm would drain their aquifer.

"Everybody else in the state of California is trying to conserve water and here all at once, boom, you guys are using it all up on us," said Ace Miller, an area resident, at one hearing.

With energy commission staffers and NextEra at loggerheads, executives warned last year that they might have to abandon the $1-billion project -- and the hundreds of construction jobs it would create -- because they claimed that Beacon wouldn't be sufficiently profitable unless they could use well water.

Energy commission staffers weren't about to budge.

"We clearly felt that this was a significant issue, not just in the context of this isolated project but also in the context that we are going to see a large number of solar power plants in the desert," said Terry O'Brien, a deputy director at the California Energy Commission, which licenses large-scale solar thermal power plants. "If we use water more efficiently, we can generate more megawatts."

But NextEra is now talking with two local municipalities, California City and Rosamond, about buying reclaimed water to cool the power plant. That would allow the company to sidestep a fight over water use while giving the cities a market for their treated wastewater.

Energy commission staffers filed documents two weeks ago that would let the Beacon project proceed as long as it used reclaimed water for cooling.

"We debated the reclaimed water issue for the last year or so, and we've come to a conclusion that unless we want to go round and round on this matter for months, if not years more, it was time to compromise," said Michael O'Sullivan, a senior vice president at NextEra.

The compromise offers other environmental benefits as well. Treated wastewater contains salt and nitrates, and by piping it to Beacon rather than returning it to the aquifer, the cities can improve the basin's water quality.

Since the solar farm will still draw freshwater until enough reclaimed water can be provided, NextEra proposed to remove thirsty tamarisk trees to help recharge the aquifer. A native of the Mediterranean, the tamarisk was brought to the American West in the 19th century for use as a windbreak. The developer of California City planted hundreds of the trees in the area, Bevins said.

An acre of tamarisks can consume 1 million gallons of water annually, said Tim Carlson, research and policy director for the Tamarisk Coalition, a Grand Junction, Colo., nonprofit group working to eradicate the trees.

Regulators welcomed NextEra's proposal to remove tamarisks, which have taken over 1 million acres in the West.

"If we could eliminate tamarisk from large areas of the West, it would have a benefit to wildlife, native vegetation and would reduce water usage," O'Brien said.

The proposal is still in the planning stages, and it's unclear how many trees would be removed and just how much water would be saved.

Carlson, who has discussed NextEra's plan with the company's consultants, said tamarisks must be replaced with low-water-use native plants. "It's not a simple calculation," he said. "You just can't say that if I do so many acres I'll save so many acre-feet of water."

For O'Brien, ending the Beacon water war could help persuade other solar companies to adopt water-efficient technology and approaches. "It sends a signal to other developers that clearly that NextEra believes that their project is still viable," he said.