The future is electric

More than a hundred years later, the world seems to finally be agreeing with M Jenatzy with the mass adoption of electric cars becoming widely accepted as the most viable option for cities faced with depleting fossil fuels and in search of greener modes of transportation.

The mass adoption of electric cars, as measured by the conversion of at least 40 per cent of petroleum-fuelled cars to electric, would reduce greenhouse gas emissions from road transportation by 24 per cent; or by 100 per cent if the cars were charged with renewable energy.

It’s easy to see the logic of such a system; and the world’s leading car manufacturers have developed an impressive fleet of hybrid and electric vehicles to satisfy consumers. What is not known, however, is if everyone decided to go electric – could our electricity grid handle it?

During the next three years – funded by an Australian Research Council linkage grant – a group of researchers from the School of Engineering at the University of Melbourne will attempt to address this problem.

Led by Professor Iven Mareels, the team will undertake the first Australian study into the feasibility of a mass integration of electric vehicles into our grid, and according to Professor Mareels the findings could influence the adaptation of electric cars in cities across the world.

“There have been a number of case studies done in Europe on integrating electric cars into existing grids, however, Melbourne is more than twice the size of any of these cities; and Australia also has the added advantage of having the space to potentially provide 100 per cent renewable energy for our fleet,” Professor Mareels says.

“So while we may not be at the forefront of this technology, if we can solve this problem in the face of such a unique set of constraints it will provide a system that can be applied anywhere in the world. If we can do it here, we will be able to do it anywhere.”

The research team will focus on two main obstacles to integrating electric vehicles en masse; how to control the supply and demand of electricity to cope with additional pressures placed on the grid; and determining the optimal placement of fast charge and battery exchange stations.

Research team member Dr Marcus Brazil says that while the mass adoption of electric cars relies on 100 per cent renewable energy to offset environmental benefits, renewables come with the penalty of inconsistent supply.

“What makes it hard is the fact that the supply of renewables is changeable, for example solar energy on a dull day or wind energy on still days. You cannot control this supply, and thus the only solution really is to control demand (not considering storage as an option),” he says.

Professor Mareels says this presents the team with one of its greatest challenges, the need to flip the grid system that currently works with supply following demand to one where demand follows supply.

“There isn’t a system currently designed like that; we really need to turn the world upside down,” he says.

“There are ways however to use our existing infrastructure more effectively. For example, Victoria can deliver 11 gigaWatts (GW) of electricity a day, but such a peak is required only a few days of the year. Most of the time, the city can run adequately on five GW. So instead of building more infrastructure to accommodate what could be a doubling of peak demand due to electric vehicles, there are ways to use our grid in a smarter way.”

Research team member Professor Doreen Thomas says a smarter electricity grid must also be matched with the efficient placement of charge and battery swap stations for the system to work efficiently.

“Even if we solve issues of supply and demand with the grid, the population won’t take up electric vehicles unless they feel confident about reliably charging without inconvenience,” she says.

“Therefore we need to know optimal locations – for both long-haul and urban drives – for this infrastructure.”

The team will consider the placement of three types of stations. Slow charge stations with a current of 15 amps and which take about 7-10 hours to fully charge a battery; fast charge stations with a current of 200 amps which take at least 30 minutes to provide 80 per cent of a battery’s full charge; and battery swap stations which automatically replace a partially spent battery with a fully charged one within five minutes.

Professor Thomas says the placement of slow charge stations is straightforward as they are really “only useful at home or work when the driver leaves the car for a long time.” Determining the best placement of charge stations for urban commuting and long-haul drives however, is a lot more complex.

“With current technology an electric car with a fully charged battery can be driven at highway speeds for about 200km,” she says.

“So on a drive from Melbourne to Sydney a driver would need to stop and recharge, or exchange a battery, six times. Hence we need to figure out which sites en route would be best to avoid congestion, increase efficiency, be close enough to new energy sources, and ensure the profitability of each station.

“In relation to urban driving, the problem lies in creating an optimal mix of fast charge and battery exchange stations, and placing fast charge stations in places where drivers would be happy to spend 30 minutes, such as near shopping centres or cinemas.”

Professor Mareels says the project’s success will rely heavily on the involvement of key corporate partners, Better Place Australia and Senergy World as well as research into economic modelling from the University of New South Wales.

While the project aims to have initial findings into station placement within 12 months, Dr Brazil hopes the project is just “part of a whole philosophical change in how the world thinks about transport.”