Electric vehicle sales have grown exponentially in recent years. Today, there are more than two dozen plug-in cars on the market, and dozens more are set to hit showrooms before the end of the decade.

That's a positive development for reducing oil consumption, but it has mixed results for the electrical grid.

As they reach mass scale, plug-in cars could, in theory, overload local electric circuits. But if managed properly, they could also be a boon for utilities looking to sell more electricity.

Some utilities have stepped up efforts to buy EVs for their own fleets and to build out public charging infrastructure to accommodate EV drivers. Some progressive utilities are also looking at ways to integrate EVs with new technologies and pricing plans, to lower charging costs and reduce strain on the electrical system.

In this episode of Rewired we look at different ways EVs interact with the power grid, and not only what that could mean for the future of plug-in cars, but also for the utility industry.