Electric car lets drivers sell back unused watts


AAAS annual conference:RESEARCHERS HAVE come up with the ultimate vehicle – an environmentally friendly electric car that plugs into the wall to sell power back to the electricity company.

The delights of a car that lets you get one up on the power suppliers comes via research funded by the US National Science Foundation (NSF). The goal is to develop “plug-in hybrid electric vehicles” (PHEV) that not only use grid electricity to meet their power needs, but can also collect electricity from the wind or sun and then sell this back into the national electricity grid. “Cars sit most of the time,” said Prof Jeff Stein, a mechanical engineering professor at the University of Michigan who heads the NSF effort.

“What if it could work for you while it sits there?”

He raised the question during a session on “green mobility” that took place at the American Association for the Advancement of Science’s annual meeting which opened yesterday in San Diego.

Chief executive and president of AC Propulsion Tom Gage drove the 150-odd miles from his base in San Dimas to San Diego in a V2G (vehicle-to-grid) vehicle, making a steady 60 m/ph all the way down. It has a maximum speed of 90m/ph and the firm likes to describe itself as a developer of electric cars “that people want to drive”.

The idea is that the car would accumulate power from a range of environmental sources, explained Prof Willett Kempton, director of the Centre for Carbon-free Power Integration at the University of Delaware who chaired the session.

The car would be plugged in at home to charge its batteries, but solar or wind or even brakes would give the car a top-up of electricity on a long journey.

Once back at home, leftover power stored in the car could then be routed back into the grid for payment at an agreed rate per kilowatt.

This is not pie in the sky. Prof Kempton described how his university had three V2G electric vehicles on the road that were actively earning money selling power back to the local grid. Each car can charge or discharge at a maximum power of 19.2 kilowatts. Because electricity is ubiquitous, there would be little difficulty setting up “fuelling” points for such vehicles, something that has slowed the use of liquefied natural gas or hydrogen gas as a fuel source.