What is this?

What is this?  As you drive north on I-15, just before you cross over from California to Nevada you'll see these three towers.  Each of them is surrounded by a small sea of steerable mirrors.  If you click the photo at right (which I took while zooming down the freeway at 75 mph) to embiggen it, you'll see that the second tower from the left is black, while the other two are shining brightly.  In reality, the two that are shining are so bright you can't look directly at them – they appear to be at least as bright as the sun.

The two that are shining here are operating power stations, and the mirrors around them have been aimed so that each of them reflects the sun onto the tower.  These mirrors move all day long, as the sun moves across the sky, to keep the reflected sunlight on target.  Thousands of these mirrors surround each tower, and collectively they focus enough light onto the flat black material of the tower to boil the water circulating under the skin.  That generated steam powers turbines that generate electricity – enough for 70,000 homes.

The black tower is just one that's not operational at the moment I took this photo.  It's mirrors are aimed so that they reflect light anywhere but on the tower.

These power stations have been in the news recently because birds have been flying near the towers.  When they do so, they are killed by the intense heat, and even partially cooked by the time they hit the ground below.  Environmentalists are, of course, trying to shut the power stations down.  Because the power stations are in California, I'd bet that they'll succeed...