Renewable energy would be a cinch if the sun shone all day and if the wind blew as reliably as the Earth spins. They don't. And even when wind turbines and solar panels are able to harness them, the sun and wind might not produce power exactly when customers want it. Without storage, the excess energy is wasted.
A123 Systems Inc. , a maker of rechargeable auto batteries, will supply lithium-ion cells to SAIC Motor Corp. for use in an electric vehicle as the U.S. startup expands ties with China’s largest domestic carmaker.