The Ivanpah solar power plant in the Mojave desert has been hailed as an integral part of California's solar surge, becoming the world's largest solar thermal installation and generating enough electricity to power 140,000 homes. 

Given the urgent need to rid ourselves of fossil fuels, such developments are usually considered a good thing. There is, however, a downside. As the Associated Press reports, the concentrated beams of sun rays, which are reflected up onto gigantic boiler towers by a huge field of mirrors, are literally cooking birds in mid-flight, raising concerns among wildlife advocates about the impact of this technology. Of course any project of this size — regardless of the technology — is going to have some negative impacts on surrounding wildlife, but federal wildlife investigators are claiming an average of one "streamer" (the term they use for a bird strike) every two minutes, a rate which Garry George, renewable energy director for the California wing of the Audubon Society, described as alarming.

This isn't the first time that renewable energy has run up against biodiversity concerns. Critics of wind farms, for example, often claim they are a cause of excessive bird fatalities, yet leading bird charities are investing heavily in renewables in an effort to fend off the threat of climate change. In general, there are a few important takeaways from this controversy: 

Ivanpuh solar plant in CaliforniaClean energy doesn't get a free pass: Combating climate change should be an urgent priority for anyone interested in protecting biodiversity, but that can't become an excuse to ignore biodiversity concerns. Some negative impacts may be unavoidable, but from solar farms designed to enhance biodiversity and sequester carbon to deepening our understanding of how offshore wind alters marine habitats, as clean energy industries mature, they have to make sure they are taking their complete environmental footprint into account. 

Not all bird deaths are created equal: When I mentioned to an ornithologist friend the death of 6,500 birds in a natural gas flare, he scoffed and suggested the story had been overblown by environmentalists looking to undermine the gas industry by any means necessary. While my friend is no fan of fossil fuels, he argued that such deaths pale in comparison to natural mortality rates for many migratory bird species, not to mention deaths caused by urban buildings, cars and the domestic cat. The same could be said for bird deaths caused by many renewable energy projects. It's not necessarily the sheer number of bird deaths, but rather how the deaths are likely to impact the well-being of the species. Raptors, for example, which are fewer in number than common songbirds, are particularly at risk from poorly sited energy projects. Given that U.S. Fish and Wildlife Service officials are saying plants like Ivanpah (at right) may have the "highest lethality potential" of all the solar technologies out there, there's a reasonable case to be made for exercising caution before approving more plants.

The greenest energy is the energy you don't use: While environmental advocates may argue over the relative importance of protecting individual species versus cutting emissions, one of the most important lessons from all of this is that there is no silver bullet in terms of energy production. We have no choice but to ramp up our renewable energy capacity significantly in the coming years, but no energy source is without its downsides. That's why efficiency and conservation must be a part of any conversation on the future of energy. It's hard to imagine a bird death being attributed to simply turning the lights off or installing a more efficient bulb.

According to the AP report, alongside exploring bird deterrents, BrightSource Energy is offering $1.8 million to fund spay-and-neuter programs for domestic cats, thus addressing a separate but extremely significant source of bird deaths nationwide. The idea, essentially, is a kind of "biodiversity offset" to take responsibility for — but not directly address — Ivanpah's negative biodiversity impact. It's an interesting approach, and certainly better than nothing, but it can't help the specific bird populations impacted by the plant. 

It just goes to show, there's no such thing as a free lunch. 

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Inset photo: USFWS Pacific South West Region/flickr)