Power Prius can give and take

THE University of Technology Sydney (UTS) has developed a plug-in version of Toyota’s Prius that can not only be recharged using a household power outlet, but can also direct electricity back into the power grid.

Launched by NSW deputy premier Carmel Tebbutt in Sydney on April 23 ahead of trials by the NSW department of environment and climate change (DECC), the NSW government-funded vehicle is claimed to be Australia’s first prototype plug-in hybrid car to employ vehicle-to-grid (V2G) technology.

However, the petrol-electric UTS Prius, named Switch, employs a similar system to the Mazda2-based evMe electric car manufactured by Energetique in Armidale (NSW), which has the ability to feed electricity back into the grid through an inverter in the same way photovoltaic solar panels do.

As we reported two weeks ago, the evMe sells for $70,000 and is powered by the latest lithium polymer (LiPO) batteries, which are also fitted to the plug-in Elantra hybrid that Hyundai will launch in South Korea in July.

Like the nickel-metal hydride (NiMH) batteries found in the Prius, they can be hooked up to a potential future intelligent power grid, or “i-grid”, such as that proposed by Better Place.

The US’s eBox electric vehicle (EV) also has a grid connect feature, while Mitsubishi’s i-MiEV city-car was the first EV to gain Australian Design Rule (ADR) approval and is in field tests with local fleets, including the NSW government.

The i-MiEV is slated to be joined in 2012 here by a Nissan EV, which is also expected to have the ability to redirect power back into the grid.

UTS’s modified 2006 Prius comprises both a power inlet and a power outlet, both positioned above the rear bumper, and will be trialled as part of a fleet of ‘green’ vehicles by the NSW Department of Environment and Climate Change (DECC), which helped fund the project.

Left: Energetique evME.

Toyota has fast-tracked its plan to trial a plug-in version of its third-generation Prius, which goes on sale in Australia in July, with vehicle fleets in Japan and the US late this year.

But neither it nor General Motors’ plug-in Volt hybrid, which Holden plans to sell here from 2012, will have the ability to feed power back into the grid.

Despite that, some observers have suggested that motorists with V2G-compatible vehicles could become “power traders” who buy and sell electricity, taking advantages of peaks and troughs in demand for power such as during peak power usage periods or during blackouts, which have been a common occurrence in Sydney recently.

If implemented widely, says the UTS and the NSW government, V2G plug-in vehicles could even influence the supply of power within their region.

“The huge benefit of this car is it offers all of the advantages of a hybrid car that combines both an electric and a petrol motor, but it also means that you could actually be feeding power back into the grid,” said Ms Tebbutt.

“So if you had these sort of cars all across the city it would be the equivalent of a huge big battery feeding back into the grid, so this is very exciting.

“At the moment it is a trial. The department of environment and climate change has helped fund this research and the car is going to be used as part of the DECC fleet as a trial.

“But some day in the future we might see a situation where everyone’s driving cars like this, which would mean using far less energy, far less air pollution and being able to feed power back into the grid.

“So it really is a world of the future, but certainly a world where the green benefits are enormous.”

UTS research project director Chris Dunstan also says the technology has enormous potential.

“The vehicle-to-grid technology this car presents could do for the automotive industry and the electricity industry what the personal computer did for computing, and what the mobile phone did for telecommunications,” he said.

“The extra batteries can store energy at off-peak times and feed power back into the grid at times of peak demand.

“On a large scale, this could level out peaks and troughs in power supply across regions.”

Exactly how much power the UTS Prius and cars like the i-MiEV can return to the grid, and therefore how many vehicles would be required to make the process worthwhile, will be the subject of investigation by the DECC and energy companies.

But both the UTS and DECC agree that incentives from power companies for consumers who feed-in to the grid, such as the tariff to be introduced by mid-year for NSW households that generate their own solar power, would be required for such a system to work.

“You could envisage a world in the future where many people have these cars and there is an opportunity to say 'tomorrow we need everyone to feed their cars back into the grid', and that will help us address a power need on that particular day,” said Ms Tebbutt.

“There would obviously need to be a financial incentive for people to do that, but we're a long way away from that at the moment.”

Mr Dunstan said the success of V2G technology in Australia would rely heavily on the support of energy companies to buy back electricity from motorists.

“If there is not the demand from the electricity industry to provide this power back in at a reasonable price and a rate that makes sense for consumers, then there is no point in pursuing the technology,” he said.

“We want to get the electricity industry excited about this technology. We want to demonstrate that it is entirely practical.”

The UTS Prius comprises extra batteries to store more electricity and plugs into a standard domestic electrical socket, requiring no additional wiring or specialised equipment for basic charging.

Mr Dunstan said a full 200km charge from a 10amp power supply will take around 15 hours, but based on an average daily commute of 40km it could be topped up daily in three hours and cost as little as 50 cents a day to charge with off-peak power.

The UTS says the running cost of its Prius was about a quarter that of an equivalent petrol-powered car, or the equivalent of 40 cents a litre using a renewable energy source. It’s claimed the prototype would save up to 2.8 tonnes of greenhouse gas emissions a year.

Meantime, the four-seater i-MiEV has a range of 160km per charge under Japanese test conditions and can be charged to full capacity from a household electricity supply in about seven hours.

Both the zero-emissions i-MiEV, which will be commercially leased in Japan this year, and the UTS Prius will be trialled as part of the DECC’s vehicle fleet to test its fuel efficiency, electricity use, emission and air pollution savings.

The Switch’s capacity to feed back into to the grid will be monitored in collaboration with EnergyAustralia, with fuel and energy data for the UTS Prius to be available online once the trial gets underway.

In tandem, the NSW government’s so-called Electric Vehicles Taskforce (EVT) continues to “explore opportunities and barriers to electric vehicle uptake in NSW” by investigating the technology, infrastructure, policy and legislation required to support the uptake of electric vehicles by NSW motorists.

The EVT comprises representatives from DECC, the NSW RTA, department of premier and cabinet, NSW treasury, department of water and energy, department of commerce, country energy, EnergyAustralia, ministry of transport and department of state and regional development.

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