New fuel cell material can run efficiently in reverse, storing energy

Enlarge / Close-up of a hydrogen fuel cell. (credit: Wladimir Bulgar | Science Photo Library)
Lithium batteries can readily smooth out short-term hiccups in the supply of intermittent renewable energy. But they're not ideal for long-term storage, since they'll slowly discharge. They also aren't great for large quantities of energy—to store more, you keep having to buy more battery. Because of these issues, there has been research into a number of technologies that scale better, like flow batteries and renewable fuel production. But these pose their own challenges, both chemical and economic.
But researchers are now reporting a possible solution to some of these problems: a fuel cell that can be run efficiently in both directions, either using hydrogen or methane to produce electricity or using electricity to produce these fuels. Their measurements suggest that, after doing a complete cycle, they get out 75 percent of the electricity they put in to start with.
Limitations abound
Batteries, as we mentioned above, don't work for longer-term storage, as they will typically lose charge slowly. They're also expensive, as adding capacity means adding more batteries. Flow batteries solve some of these problems by storing the charged and discharged forms of a chemical in different tanks; larger or additional tanks are cheap, making expanded capacity relatively simple and inexpensive. But flow batteries aren't as efficient as traditional batteries, and the chemicals they use can be toxic or corrosive.
Read 12 remaining paragraphs | Comments