Nearly all the plastics sold today come from petroleum and aren’t biodegradable. But researchers at Metabolix in Cambridge, Massachusetts, are genetically engineering switchgrass to produce a biodegradable polymer that can be extracted directly from the plant.

That could transform the economics of making biodegradable polymers. Metabolix already sells such a polymer, but it’s produced by bacteria that feed on plant sugars in expensive fermenters. A plant-based process, which could use crops grown on marginal lands, would require less equipment.

Solar panel installations continue to grow quickly, but the solar panel manufacturing industry is in the doldrums because supply far exceeds demand (see “Why We Need More Solar Companies to Fail”). The poor market may be slowing innovation, but advances continue; judging by the mood this week at the IEEE Photovoltaics Specialists Conference in Tampa, Florida, people in the industry remain optimistic about its long-term prospects.

Stanford researchers are developing rooftop panels that cool buildings by sending heat back into space, a technique that could be more efficient than running an air conditioner from solar panels. 

Electrical engineering professor Shanhui Fan has designed a device which uses materials that allow him to manipulate how heat and light affect building temperature. He envisions flat rooftop panels which could greatly cut down on daytime cooling energy or be used to cool homes that don’t have access to grid power and air conditioning.

The conventional wisdom is that batteries, particularly lithium-ion batteries, are way too expensive to be used on the electricity grid in a financially viable way. Chris Shelton begs to differ and he has two years of data to make his case.

Shelton is the president of AES Energy Storage, which has developed 150 megawatts worth of energy storage projects in four locations using giant lithium-ion batteries. The trick to making them economic is using them for what they’re good at and in this case, that’s speed.