Electric cars can help top up the grid

Tritium charging stations.

Australia’s adoption of electric ­vehicles is at risk of falling behind other developed nations, though with policies such as the one announced by Labor — which calls for half of all new vehicles sold by 2030 to be electric — we may soon see increased uptake and, with it, more infrastructure.

That EV initiatives are now a political issue, particularly when partnered with climate change initiatives ahead of a federal election, shows that knowledge and interest is increasing and that the benefits are clear: EVs improve the quality of our air, which ultimately leads to a better standard of living.

But that’s just the beginning. An emerging possibility is that EVs could be an energy asset that charges at one location, stores excess energy, and then delivers it back to the grid when and where it’s needed. While EVs today only import electricity, and EV charging stations only send electricity to vehicles, vehicle-to-grid-enabled EVs could feed electricity from their batteries back to the grid. Once this technology is widely available, EV owners will be able to use it to power their homes or sell excess energy to utilities.

Powered by the pedal

EV batteries allow the fleet of vehicles as a whole to store surplus grid energy from intermittent renewable resources like solar and wind. This relies on the vehicles being grid-connected for most of the time — both at home and at work. Whenever the wind blows, or the sun shines, there is a guaranteed group of customers to purchase the energy.

EVs have more capacity than they need on a regular basis: according to ABS figures, the average Australian travels about 16km a day in their vehicle, while most EVs have a range of several hundred kilometres. And despite some car owners’ concerns, discharging the battery won’t have a great impact on its useful life, because a typical battery already outlasts the vehicle.

Using V2G technology — such as that found in the forthcoming Nissan Leaf, due on these shores in August — EV owners could power their homes with this excess energy stored in their EV batteries. Current vehicles with a 300km-plus range on a 60kW battery pack could run a typical house, including airconditioning, for four to five days.

That’s handy in an emergency situation, but the real opportunity is selling energy back to utilities, balancing renewable production with energy demand. Using rates that change in real time, utilities could encourage EV owners to charge up during the day when there is excess (and therefore cheap) solar energy on the grid and sell the power back during the evening peak.

EV owners could charge their vehicles at work and then drive home and plug the car into their home charger. As demand for energy ramps up in the evening, the utility could buy power from full EV batteries.

Meanwhile, drivers would earn more from selling their battery power than they paid for it.

Incentives drive adoption

Utilities hold the key to unlocking EV-to-grid capabilities, and there’s ample reason for them to use it. Within the next several years, bidirectional charging could unlock a 100 per cent renewables-powered grid — without any coal, nuclear or gas storage baseload — by balancing peaks and valleys in renewable energy. Once home batteries coupled with rooftop solar become widely accessible, EV owners may choose to leave the grid in favour of powering their homes with solar energy and battery storage, with the car battery available to cover any shortfall.

Utilities need to retain these customers and incentivising EV drivers to sell power back to the grid is the best way to keep them hooked up. If utilities make it financially attractive, drivers will give them access to all those big mobile battery packs when the sun isn’t shining. If the incentives are right, drivers will be better off selling power back to the grid and charging according to grid needs than using their EV to top up their home battery.

Additionally, using the EV batteries lowers the overall need for storage of all that excess renewable energy — utilities could leverage their customers as a mobile storage asset.

Price signals that encourage EVs to charge and discharge at optimal times also will help utilities avoid strain on the grid from the growing EV population. Owning an EV will increase household electricity consumption by about 50 per cent, according to a new study by LEK Consulting and Tritium.

Using EVs to help balance the grid, instead of demanding more from it, should be an easy choice for drivers and utilities. When we connect EVs to the grid, a brave new (renewably powered) world for low-emission transportation and power will come into view.

But what we need in Australia to maximise this potential future, first and foremost, is more electric vehicles on our roads.

Paul Sernia is co-founder and chief product officer for Tritium, which builds DC charging solutions for electric vehicles.