Electricity powers our lives. But the need for it changes monthly, even hourly. The source of electricity often varies as well. One solution? Batteries.

Dr. Jonathan koomey is a project scientist at Lawrence Berkeley National Laboratory: "We need to work on innovations that will help us use intermittent electricity generation technologies. So that means being able to store electricity thats generated during the daytime from solar and then putting it back in the grid at night."

Affordable and innovative batteries are key to updating america's aging electrical power grid. And for enabling renewable wind power as well as solar.

Koomey: "The trick is to develop storage technologies that will be cheap enough to allow us to disperse them widely throughout the grid".

The federal stimulus package includes $2 billion for grants to help us companies test and manufacture advanced battery systems. Helping to provide renewable power where - and when - it's needed quickly and efficiently.