November 30, 2010
| by Steven Castle
Smart Grid Cars
Electric utilities are eyeing the EV with great concern, and with good reason. A big part of the utilities’ smart grid initiatives is designed to reduce peak power loads that occur when most people use energy, such as from 3 p.m. to 8 p.m. We come home, turn stuff on, and bam, there’s a peak load. Add 240-volt EV chargers in every home—or even some of them—and you’ve got a massive electrical demand.
This is partly why utilities want to institute programs like time-of-use pricing, in which electric rates during peak periods like 3 p.m. to 8 p.m. will be more expensive, and demand response, in which the homeowner voluntarily allows the utility to turn down or shut off appliances like air conditioners and EV chargers to avoid instituting brownouts or having to buy expensive power elsewhere.
A solution to this problem could come in the form of a charging unit equipped with some type of communications technology, such as ZigBee, so it can receive signals from a two-way smart meter, with which homes on the smart grid are being equipped. EVs, too, already come with on-board charging options.
But will this be enough to enable your EV to charge automatically less expensive times? It’s likely that you would also need a processor in your home to manage your charging preferences and that can receive signals from your mobile device so that you can change your charging options. You may also need that processor to make sense of the rate information coming from the utility. All of this will be best facilitated by a home energy management or control system.
This system will keep track of all your home’s energy use, automatically shutting off appliances, devices and electronics that aren’t needed, and keep track of the production from alternative sources of energy such as solar electric panels.
It could also help you move energy around. Smart grid advocates look to technology called V2G, for vehicle to grid. It’s two-way power, meaning your home energy management and control system could at times borrow power from your electric car’s battery to power something in the house, instead of buying expensive power from the utility to do so.
Steven Castle is Electronic House's managing editor. he has been writing about consumer electronics, homes and energy efficiency topics for two decades. He is also the co-founder of GreenTech Advocates