How a Solar Farm Set Hundreds of Birds Ablaze

It's no secret that solar power is hot right now, with innovators and big name companies alike putting a great deal of time, money, and effort into improving these amazing sources of renewable energy. Still, the last thing you'd likely expect is for a new experimental array to literally light nearly 130 birds in mid-flight on fire.

And yet, that's exactly what happened near Tonopah, Nevada last month during tests of the 110-megawatt Crescent Dunes Solar Energy Project.

According to Rudy Evenson, Deputy Chief of Communications for Nevada Bureau of Land Management (NBLM) in Reno, as reported by Re Wire, a third of the newly constructed plant was put into action on the morning of Jan. 14, redirecting concentrated solar energy to a point 1,200 feet above the ground.

Unfortunately, about two hours into the test, engineers and biologists on site started noticing "streamers" - trails of smoke and steam caused by birds flying directly into the field of solar radiation. What moisture was on them instantly vaporized, and some instantly burst into flames - at least, until they began to frantically flap away. An estimated 130 birds were injured or killed during the test.

But worry not, green home owners. The solar energy we are talking about here is not like the solar panels that top your roofs. Solar panels don't produce enough heat to cause such a scene.

The plant in question, which was expected to come at least partially online this month, runs on 17,500 heliostat mirrors - each the size of your average garage door - that concentrate and reflect thermal solar energy at a tall center tower. This tower uniquely contains molten salt, of all things, which is circulated to produce steam and generate electricity. Excess heat is stored in the salt and can be used to generate power for up to 10 hours, including during the evening hours and when direct sunlight is not available. (Scroll to read on...)

[Credit: SolarReserve]

As a self-sustaining energy source that only needs water and sunlight, the new plant certainly sounds like a boon for the natural world.

"The Crescent Dunes Solar Energy Project will reduce the nation's reliance on fossil energy supplies, producing enough solar energy in one year equivalent to about one-eighth of the total output of Hoover Dam," developer Solar Reserve announced during the groundbreaking of the project in 2011.

What's more, this isn't even the first plant of this kind to be seen in the United States. The Mojave desert is home to an older heliostat power plant more than 10 times this latest project's size. Called the Ivanpah Solar Electric Generating System, this plant boasts a stunning 300,000 solar mirrors to heat a specially designed "water furnace" (which is less efficient than the molten salt appropach).

Unfortunately, the redirected sunlight causes such a wide sphere of superheated radiation that  the plant sees one streamer every two minutes, according to investigator estimates.

Officials behind the project have refuted that claim, saying that most of the streamers are floating trash or wayward insects, but federal wildlife officials have begun calling these 'eco-friendly' power towers "mega traps" for wildlife. (Scroll to read on...)

According to The Associated Press (AP), many biologists call the number of deaths "significant" and suspect that the streamers are caused by a chain of attraction - that is, insects are drawn towards the bright plant's light, which in turn attracts birds looking to feast on crispy bugs.

However, it's important to note that unlike the California and Nevada plants, earlier, smaller versions of these power towers tested in Europe did not regularly see these kinds of incidents. And when the Crescent Dunes plant ran a second test using less mirrors, no more birds burst into flames.

Garry George, renewable-energy director for the California chapter of the Audubon Society, even told the AP that while the reports are "alarming... it's hard to say whether that's the location or the technology" that's behind the deaths. It may simply be that more birds follow air paths that happen to cross the new solar fields.

He added that like with any new technology, "there needs to be some caution," and hopefully engineers can learn from these early mistakes.

US Fish and Wildlife Service officials are now waiting for a death toll for a full year of operation at the Ivanpah plant. The subsequent report may impact plans for future solar power towers in the United States.

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