Birds migrating from the Arctic to Central America pass through the Mojave: Ivanpah could conceivably depress bird populations across half a continent.
Ivanpah installation a zone of death for tortoises, raptors
by Chris Clarke / Earth Island Journal
The world’s largest solar thermal power plant officially went online one week ago today, on February 13. At a ceremony in the Mojave Desert south of Las Vegas, with US Energy Secretary Ernest Moniz presiding, the Ivanpah Solar Electric Generating System for
mally joined California’s power grid.
The cleantech trade press trumpeted the milestone in glowing terms only rewritten corporate press releases can offer. One article went so far as to call it the “Hoover Dam of Solar,” though whether that is a good or bad thing depends on your view of river impoundment. Reaction to the opening from other quarters was decidedly nuanced. When it was proposed in 2007, Ivanpah was first lauded as the future of clean energy. Now, the project is rarely covered in the press without the epithet “controversial” attached, aside from those glowing reports in the tech press.
Ivanpah’s three units each consist of a 459-foot power tower surrounded by more than 100,000 independently targetable mirrors, called “heliostats.” The heliostats focus the harsh Mojave sunlight on boilers atop the towers, where the concentrated solar radiation (a.k.a. “solar flux”) generates steam. The steam turns turbines, which generate electricity. The three units combined will generate up to 377 megawatts of power for Pacific Gas & Electric and Southern California Edison.
In a nation struggling to come to a sane climate policy, Ivanpah might seem like an unambiguously good project. If the nearly 4,000-acre solar plant had been sited somewhere else, that might have been closer to the truth. But located where it is, this week’s coverage of the opening ceremony wasn’t complete with the word “controversial.”
From the start, wildlife advocates opposed the Ivanpah plan. Its nearly 4,000 acres, perched on an alluvial fan a few miles from the Mojave National Preserve, was some of the best remaining habitat for the desert tortoise, which the federal government lists as a threatened species. Tortoise biologists hired by project backer BrightSource Energy surveyed the site and came back with an estimate of about three dozen tortoises on the site.
Many other biologists felt that estimate was off. The survey was done during a very dry year, and during droughts tortoises tend to stay in their deep burrows. They’re easy to undercount. The site was also the home to 80 percent of the known California occurrences of Asclepias nyctaginifolia, a rare milkweed, and to dozens of yuccas more than 500 years old. Most national environmental groups supported the project anyway, citing its benefit to the nation’s greenhouse gas footprint.
Early opposition centered around the Sierra Club’s California-Nevada Desert Committee, which formed a nucleus of organizing to which other small groups flocked. Desert Committee activists attempted to persuade the Sierra Club’s national office to oppose the project, in court if necessary, due to its threats to the tortoise and other species.
But in 2010, mainstream green groups were talking openly about how Ivanpah would be the destructive project they purposefully didn’t oppose, to prove they were serious about combating climate change and give them leverage to oppose worse projects. The Sierra Club’s board of directors voted not to oppose the project. Michael Brune, the Club’s then newly installed executive director, sent out a memo announcing the decision to desert activists that began, “No one said that clean energy would be easy.”
Ivanpah quickly proved more destructive than the Club and other groups had expected. When construction started in 2011, the limit of 37 tortoise “takes” the US Fish and Wildlife Service (USFWS) had allowed over the life of the project was reached in a matter of weeks. (A “take” is a legal term meaning any kind of potentially negative interaction with a protected species, ranging from handling and harassment to injury and death.) After halting construction on the project in April of that year, FWS quickly revised its assessment of the project’s risk to tortoises. The agency determined that construction would actually affect as many as 3,000 tortoises, with the possibility that as many as 700 baby tortoises might be killed during construction without being detected.
After making that determination, USFWS rewrote its authorization for the Ivanpah plant and construction started again.
To their credit, BrightSource and its partners in Ivanpah — NRG Energy and Google — spent millions of dollars during the next few years caring for the tortoises they found on site, with some of the nation’s best wildlife biologists and veterinarians involved. But another wildlife issue came up in 2013: the effect of concentrated solar flux on birds and other wildlife.
In 2011, BrightSource had several other proposed projects on the table in the California desert. All of them would be much larger than Ivanpah, with more intense solar flux. Environmental activists started asking tough questions during hearings on these projects. For example, what would happen to birds, bats and insects that fly into that flux?
An answer came in late 2013 at Ivanpah. Mortalities from solar flux had been noted since testing began in March of last year. In October, a startling number of dead migrating birds on the site led federal wildlife biologists to a sad conclusion. The bright solar flux likely attracts insects, which attract small birds, which attract raptors: an entire food chain drawn into a zone of lethal solar flux. This ecological trap’s effect on migrating birds was especially troubling. Birds migrating from the Arctic to Central America pass through the Mojave: Ivanpah could conceivably depress bird populations across half a continent.
The solar flux issue has contributed to at least three BrightSource projects being suspended. The most recent one, Palen in Riverside County, was nearly declined by the California Energy Commission based almost entirely on the solar flux threat to birds. Instead, BrightSource and its partner, Abengoa Solar, suggested that mortality data be collected at Ivanpah so that the energy commission could have a better sense of Palen’s danger. The commission agreed, meaning that Ivanpah has now become a kind of prototype wildlife death lab for solar power tower projects.
This might all be a regrettable necessity — a consequence of our need to get off fossil fuel electricity — were it not for the astonishing drop in costs of photovoltaic technology that may doom large desert solar projects like Ivanpah anyway. Startling drops in costs of PV panels (the kind of solar technology that is usually used on a small to medium scale on homes and businesses, and different from the technology that BrightSource uses) sent prominent solar thermal companies into bankruptcy between 2010 and 2012. BrightSource itself canceled a planned initial public offering of its stock in April 2012 as more and more analysts suggested the future belonged to PV.
That momentum hasn’t changed. In its coverage of Ivanpah’s ribbon cutting, The New York Times suggested that the era of large desert solar might well be over. It’s just too much easier, cheaper and quicker to cover rooftops and landfills and other already disturbed landscapes with solar panels, which have no moving parts and are thus far cheaper to operate than turbines operating at high temperatures.
Which means Moniz’s ribbon cutting may have signaled more of an end than a beginning.
