It's a truism of the smart grid set – to bring millions of plug-in hybrid or electric cars to the public, utilities will have to find a way to make sure they don't crash the grid with their recharging needs.

And to take it a step further, it would be nice if those batteries could serve as backup power for a stressed-out grid as well via so called "vehicle-to-grid," or V2G, technology.

That's the future that a consortium including the University of Delaware, electric vehicle system maker AC Propulsion, utility Pepco, regional transmission organization PJM and demand response company Comverge are working on.

So far it's a small test, involving a handful of electric cars outfitted with University of Delaware-developed software that allows grid operators to suck the batteries' power when needed, without leaving them so discharged that commuters can't get home after work.

But the Mid-Atlantic Grid Interactive Cars Consortium, or MAGICC, as the group calls itself, has grander plans – a fleet of electric cars that can be aggregated to become a genuine resource for utilities to tap for their second-to-second peak power needs.

The city of Newark, Delaware got the ball rolling last month with a six-vehicle test, and the consortium brought one of its AC Propulsion-modified Toyota Scion cars to demo at the DistribuTech conference in San Diego this week.

Paul Heitmann, Comverge's director of business development and "EV/V2G specialist," says the group intends to expand the pilot to hundreds of cars soon.

As for Comverge's role, "We'd be sort of the retailer," building the platform to allow cars to be aggregated as a group as a power resource for utilities, Heitmann said. That fits in with the company's business of

MAGICC isn't the first group to look into the impact of plug-in vehicles on the grid. The Electric Power Research Institute is working with General Motors Corp. and Ford Motor Co. on projects (see Prepping for Plug-Ins to Hit the Grid).

In March, smart grid software developer Gridpoint tested its ability to manage a utility's ability to manage vehicle charging with Duke Energy (see Laying the Grid Groundwork for Plug-In Hybrids).

In September, Gridpoint bought vehicle-to-grid software developer V2Green (see Gridpoint Gets $120M, Buys V2Green), and has since tested its capabilities in a pilot project with Xcel Energy's SmartGridCity project.

And in terms of a real-world test, BMW said in November that it will lease 500 of its electric-powered Mini cars to customers in California, New Jersey and New York over the nest year.

All these tests better lead to something, if electric and plug-in hybrid cars are to have a future. A study by DOE's Oak Ridge National Laboratories found that the United States would have to build 160 new power plants to handle plug-in vehicles by 2020 if nothing is done to integrate them into the grid.

But if technologies for controlling those charge-ups on a grand scale can be implemented, that additional power resource needs would be reduced to a range of eight power plants to none at all, the report stated.

One thing the MAGICC consortium is focusing in on is making sure that software and systems for vehicle-to-grid technologies remain open, Heitmann added.

"Let's develop it and open it to everybody," he said. That could be important as utilities and grid operators develop markets for buying massed car battery power for backup during peak load times, he said.

Of course, plug-in vehicles aren't really a problem for the grid at present, since there probably aren't more than a thousand or so on roads today.

But with Toyota, GM and other automakers promising to bring mass-produced plug-in vehicles to market in the coming years, startups like Tesla Motors and Fisker Automotive jumping into the market, and state and federal incentives emerging for people who want to buy them, it's probably a good idea for utilities to get ready.