Ellen Phiddian
Cosmos science journalist
Many Australians now sell solar power generated on their rooftops into the grid on sunny days. In a handful of years, it may be possible to do the same thing when it’s dark – with the help of an electric vehicle (EV).
Nascent vehicle-to-grid (V2G) technology operates around the idea of EVs with bi-directional chargers: they can charge from power sources, but they can also be used to provide power. EVs could be used as mobile grid storage, with owners charging them on rooftop solar and then either using the power themselves later in the evening, or selling it back to the grid.
At the moment, the technology is rare in Australia, with both technological and economic research still needed to figure out how it will best fit into our energy mix.
Some of that research has just started at a model house in Port Macquarie, on the Mid-North Coast of New South Wales.
“If we can get the energy optimisation answer right with vehicle-to-grid technologies, we can avoid unnecessary expansion on the network, and we can help customers minimise their energy bills,” Brad Trethewey, manager of innovation at energy company Essential Energy, tells Cosmos.
Essential Energy has partnered with the CSIRO to trial V2G technology. The trial is running at a mock-home, fitted out with solar panels, batteries, a hot water system, and appliances including a fridge, a dishwasher, a TV and a pool pump.
“In this first phase, we’re looking at how vehicle-to-grid can be technically integrated into the home of the future. We’re doing tests where the vehicle powers a lab for periods of time, and we’re doing scheduled discharge and charge cycles with the vehicle,” says Trethewey.
“The second phase of the test is how we can coordinate the vehicle-to-grid technology, in a more integrated sense, with customers’ appliances and their flexible loads to minimise bills and maximise the use of their renewable energy resources – so, solar.”
The team expects the first phase to finish in late March next year.
“I don’t have an end date for second phase, because we expect the emergence of V2G to have ongoing research needs, even after it’s technically available,” says Trethewey.
While there are currently EVs being made with V2G technology, they’re not yet much use in Australia. Many EVs aren’t sold here with the right hardware or software, and regulations and standards around electricity can’t yet accommodate it.
Part of the work in the trial will be helping to assess how EV and solar owners might best use V2G.
“What is the value proposition? Does the market need to change as a result of vehicle-to-grid capability, or is most of the value in self-consumption – using it for your own energy consumption and needs?” says Trethewey.
Once the second phase of the trial has wrapped, Trethewey says that the team will be interested in seeing how V2G plays out at scale – and in different areas, with different energy mixes.
One way or another, though, he expects bi-directional chargers and energy-storing EVs to become commonplace – soon.
“I think that there’s an inevitability about this. Once vehicle manufacturers produce vehicle-to-grid capability in their cars, cars are going to come with it, and when customers realise the value of that in terms of reducing their energy bills in their house, it’s going to become widespread.”
When might this happen? Trethewey thinks it’s possible before the end of the decade.
“Most vehicle manufacturers are saying they’re going to have some vehicle-to-grid capability in Australia, they’re talking late 2025, early 2026. Now, that doesn’t mean they’ll have it switched on – it just means that they’ll have the vehicles capable for it.
“So the next five years, I think, is probably well within reason.”
