Environmental impact of desert solar installations

NIPTON, California – On the construction site of the $2 billion Ivanpah solar power plant here, burly labourers slowly walk around their trucks, dropping to their knees to peer underneath before turning the ignition. Hanging on each rear view mirror is a placard warning workers to “Look under your car for desert tortoise before you drive away!”

Road graders and backhoes crawl along at 116 kilometres per hour, led by biologists wearing green hard hats who scan for tortoises in a landscape studded with creosote bushes. “Nobody is allowed on the site without a biologist to escort them,” said Mercy Vaughn, the lead biologist for BrightSource Energy, the Oakland, California, company that is building the 370-megawatt power plant, the first large-scale solar thermal project to break ground in the United States in two decades.

The imperilled desert tortoise sets the pace here in the desert Southwest, and how developers deal with a host of protected plants and animals has become crucial to getting vast renewable energy projects built. That means hiring scores of biologists, managing the relocation of species and acquiring thousands of hectares of replacement habitat.

With seven large solar power plants already approved that would cover 109 square kilometres of the California desert with huge mirror arrays, solar dishes and towers, environmentalists and regulators have increasingly become concerned about the impact that industrialization of the desert will have on fragile landscapes.

“If wildlife issues are not at the top of a developer’s list, they should be,” said Karen Douglas, the chairwoman of the California Energy Commission, which licenses large solar thermal power plants. “The footprint of these solar projects is unprecedented, and obviously they can impact a range of species.”

Developers underestimate the importance of desert animals at their peril.

The California Energy Commission in October, for instance, approved Tessera Solar’s huge Calico project in Southern California only after the company agreed to slash the project nearly in half to avoid having to relocate most of the 104 tortoises found on the site this year. And the commission’s staff has indicated that it is unlikely to recommend the licensing of Solar Millennium’s 250-megawatt Ridgecrest power plant because of its impact on the desert tortoise and the Mohave ground squirrel.

In late October, the Quechan Indian Tribe sued the federal government over its approval of a second Tessera power plant, contending that the 709-megawatt Imperial Valley Solar Project would harm the flat-tailed horned lizard, an animal proposed for endangered species protection. It is part of the tribe’s creation story.

As the first big solar thermal power project to undergo licensing in 20 years and the first to begin construction, Ivanpah is being watched closely by environmentalists, regulators and competitors over how it handles wildlife challenges.

BrightSource, which is backed by Google, Morgan Stanley and several oil companies, has signed contracts to deliver 2,610 megawatts of electricity to utilities in the state. It took three years for the project to be licensed by the California Energy Commission as BrightSource and environmental groups tussled over the power plant’s impact on the desert tortoise, bighorn sheep and other species that roam the 1,450-hectare site in the Mojave Desert.

BrightSource shrank Ivanpah by 12 percent, reducing the number of desert tortoises that would have to be relocated and avoiding an area of rare plants. The portion of the project that would most affect wildlife was cut by 23 percent.

The energy commission in September licensed Ivanpah over the objections of the Sierra Club, the Center for Biological Diversity and other groups that argued it would eliminate high-quality habitat for the tortoise.

“If you put a project in the wrong place and even do some things to reduce its impact, it’s still bad,” said Lisa Belenky, a senior lawyer with the Center for Biological Diversity in San Francisco. “We’re really trying to get companies and regulators focused on lands that have already been disturbed.”

The Ivanpah site is just over the Nevada border, about 64 kilometres southwest of Las Vegas. The neon glow of two hulking casinos looms in the distance. An incongruous patch of luminescent green marks an 18-hole golf course adjacent to the site.

“Everyone wants to do the right thing, but everyone is concerned because there are so many precedents that are being set since we’re the first ones through the hoop,” Todd Stewart, the Ivanpah project manager, said recently as he stood amid the desert scrub as biologists tracked an orange and brown tortoise that had been outfitted with a radio transmitter. The tortoise, which the biologists said was probably 30 to 40 years old, was about the size of a soccer ball.

By 2014, nearly 16 square kilometres of government-owned desert surrounding Stewart will be covered with 347,000 mirrors, each the dimension of a billboard. The mirrors will focus the sun on three 140-metre towers topped by water-filled boilers to create steam that will drive turbines to generate electricity.

BrightSource executives take pains to point out that they designed Ivanpah to minimize its disturbance of the desert. Vegetation, for example, will be trimmed rather than ploughed as equipment is installed.

Following conditions of its license, the company fielded an army of more than 50 biologists to capture and radio-tag tortoises in the 364-hectare first phase of the project to ensure none were harmed as construction began.

That included baby-sitting a juvenile tortoise discovered in the construction zone until a radio transmitter could be attached. “We have someone tracking all the tortoises continuously so whenever we determine one’s at risk, someone gets put on it,” said Vaughn as a young, palm-size tortoise was weighed and measured.

Artificial burrows have been constructed in holding pens where the tortoises will be kept until they are relocated to a site within a kilometre of Ivanpah next spring. BrightSource will monitor the tortoises for the next three years.

As Vaughn escorted reporters through a part of the site not under construction, she spotted a tortoise with a partly crushed shell. She said the injury was most likely caused by one of the off-road recreational vehicles that the government had permitted to crisscross the desert here.

Just how much of a wild card wildlife can be for big solar projects became clear after the biologists completed their pre-construction tortoise sweeps. Surveys conducted while Ivanpah was being licensed found 25 tortoises on the original 1,619-hectare site. In late October, though, biologists came across 23 tortoises in the project’s 364-hectare first phase and discovered another 23 tortoises outside that boundary.

BrightSource has a federal permit to move a maximum of 38 tortoises, which is the number of animals the relocation site can support. If more than 15 tortoises are found in the project’s remaining phases, the government must conduct a new analysis of its impact, according to Larry LaPre, a biologist with the U.S. Bureau of Land Management.

He noted in an e-mail that weather conditions can account for discrepancies in the surveys, as the original research was conducted in a drought year, when the animals would be less active. “Estimating tortoise numbers is an inexact science in any case,” he said.

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