Vehicle to grid technology — commonly abbreviated as V2G — is a most intriguing concept. In theory, people wouldn’t need to purchase a storage battery like a Tesla Powerwall for their homes, as they could simply plug their electric cars in and let their rooftop solar system charge up their battery. In the event of an electrical outage, they could tap into the energy stored in their car’s battery to power their homes.
V2G has significant potential advantages for utility companies as well. Since private automobiles are only in use about 5% of the time during a normal day, they could be connected to the grid the other 95% of the time. That would allow them to act like a lot of small grid storage batteries — accepting excess electricity from the grid when it is available and giving back electricity to the grid when it is needed.
As always, there is slippage between theory and reality. In theory, all the batteries in all the electric cars in the world could serve multiple purposes. They could power our cars, store energy from rooftop solar systems, power our homes on occasion, and help balance the utility grid. But what is the reality? No one knows. There are lots of opinions, theories, and guesstimates, but little actual research has been conducted to find out exactly what V2G technology can — and cannot — do.
Researchers at the University of Salford in the UK are about to change all that. According to a report in Science Daily, researchers plan to use the university’s Energy House to study the flow of electricity to and from a car battery during normal residential use. The Energy House is a typical English home built in 2011 inside a university building to study energy conservation strategies. It enjoys an international reputation for testing energy efficiency in residential dwellings.
“At any given time, 95% of cars are parked and their batteries free, which means stored power can potentially flow from car to house,” says Will Swan, professor of building energy performance at the University of Salford. “We’ll be testing this in Energy House which can be subjected to simulated climates — sun, wind, snow and rain as well as allowing us to control countless energy use scenarios. It’s the perfect living laboratory to test what V2G can do.”
“It’s not as simple as drawing on the car battery when you need it because there are so many variables such as the weather, household activity, and so on,” Swan adds. “In terms of energy efficiency, we know that renewables are problematic because they don’t always generate power when want it. Hence storage options are increasingly important. We can look at the car or other vehicle as both a battery and a storage tool, but we need to understand better how all these elements relate.”
The research will be conducted in cooperation with Honda, which is providing EV chargers for the experiment, and Upside Energy, a Salford based company which runs a cloud service to aggregate energy stored by homes and businesses. “These tests at a [Energy House] will help us establish a baseline of data which could be scaled up to hundreds if not thousands of homes and vehicles and start to identify what services can be offered to householders and the grid in the future,” says Neil Jones, program manager for Upside Energy.
The research will hopefully clarify what the benefits of V2G technology are. At present, very few electric cars are being manufactured with V2G capability. The Salford research could be a key to making use of the technology more widespread. If there are downsides to V2G systems, it will identify those as well. Either way, having more knowledge rather than less is always a good thing, except perhaps in Idaho.