They just sit there most of the day and night, storehouses of electricity, doing nothing. So in an era of increasing renewable energy penetration, why not use electric vehicles and their batteries to help make way for more variable renewable energy?

It’s an idea that’s been kicked around a lot, and now the Chinese are getting on board with the possibility.

“In the future we think the electricity vehicle could be the big contribution for power systems’ stability, reliability,” said Wang Zhongying, director of the China National Renewable Energy Center and deputy director general of the Energy Research Institute at China’s National Development and Reform Commission.

According to Forbes contributor Jeff McMahon, Wang directed a new study on how China could achieve 85 percent renewables in the electricity sector by 2050. “The study gets there by relying on what has become known as Vehicle-to-Grid technology, which has emerged as almost a surprise side effect of inexpensive solar panels and clean-energy policies in places like California and Germany,” McMahon wrote.

Speaking of California, in January, BMW announced the “BMW i ChargeForward Program,” a pilot study with the utility Pacific Gas & Electric Company that hopes to demonstrate “how intelligent management of electric vehicle charging can contribute to improved electric power grid efficiency while reducing total cost of electric vehicle ownership.”