Compost isn’t just for your garden anymore: Scientists at the University of the West of England have created a microbial fuel-cell battery powered by organic waste. The miniature battery converts biochemical energy from food into electricity, using E. coli bacteria that release hydrogen atoms as they break down carbohydrates. The fuel cell runs on sugar cubes, and the scientists are currently using it to run a light-sensitive robot. But eventually a series of connected cells, sold for about $15 each, could power home appliances, the scientists say. And possible creative improvements abound: “They aim to move on to carrot power,” New Scientist magazine reported.