A common sight in the sky above the world's largest solar thermal power plant is a "streamer," a small plume of smoke that occurs without warning. Closer inspection, however, reveals that the source of the smoke is a bird that has inadvertently strayed into the white-hot heat above the plant's many reflecting mirrors. Because the BrightSource Energy plant near Ivanpah, California, uses supercritical steam rather than photovoltaic energy, the sun's heat is reflected off more than 300,000 mirrors to a single point, which is used to drive a steam turbine. The downside of that, of course, is that it's lethal for any wildlife that strays into the picture -- a problem that was recognized well before the facility opened, but now the government has gotten involved.