The production tax credit for renewable energy expired—most recently—at the end of 2013, and it’s unclear if Congress will renew it again. The program gives wind farms 2.3 cents for every kilowatt-hour of renewable energy they pump into the U.S. grid. Since it was enacted in 1992, the incentive has driven a sevenfold increase in the number of U.S. turbines. “Wind has grown so much that it’s approaching hydroelectric in scale,” says Gwen Bredehoeft, an analyst with the U.S. Energy Information Administration. Without the tax credit, Bredehoeft says, new turbine construction will probably stall until at least 2030, when the country will need more energy generation. Until then, this is the American wind-energy landscape. 

The Porsche 918 can make a claim that other supercars can’t: It’s a blueprint for what everyday sports cars will be like in the next few years. Unlike models in the past, they won’t have huge engines with bad fuel economy. Instead, they will rely on electric motors and quick-charging batteries supplemented by smaller gas engines.

Toyota has donated 208 used Camry Hybrid batteries to Yellowstone National Park to power a cluster of five buildings in the wilderness. Though a couple of hundred batteries is not a lot when compared to the millions in circulation, the altruistic gesture has bigger implications: It shows what can be done with large, expensive battery packs from hybrid and electric vehicles once they’ve outlived their usefulness as a power source for automobiles.

The conceiver of one of mankind's coolest ideas for boundless clean energy died last week. He was 90 and first published his ideas in 1968, a year before NASA put a man on the moon. In its December 1972 issue, Popular Science described engineer Peter Glaser's proposal:

Don’t let NASA monopolize robotic exploration of the solar system. Using a couple of gear motors, solar panels, and leftover LEGOs, you can build a sunshine-powered robot that ambles around a strange landscape: your backyard. Obstacles such as rocks and curious children can’t be avoided, since there’s no software or sensors to control the steering, but this project is a fun introduction to solar-powered electronics.

In February, the Ivanpah Solar Electricity Generating System opened over a 3,500-acre stretch of the Mojave Desert. The solar thermal farm operates at 392 megawatts—just under 1 percent of California’s total energy production, or enough to power 140,000 homes.