Solar

In the race for the next generation battery, lithium-ion technology has made huge leaps in recent years. But the power packs continue to have drawbacks: they use raw material mined in unstable countries, they’re dangerous if they break and they could pack more power.
Bioenergy

It was California’s biggest fire yet. In late July and August, wildfires devastated an area north of San Francisco far bigger than New York City, destroying more than 100 homes and injuring 2 fire fighters. It’s just one in a rash of fast-spreading blazes that have killed at least 56 people this year and last in the Golden State.