Cities running on car batteries? Just so crazy it might work

TOKYO: When Damien Maguire moved to the countryside outside Dublin, he struggled to keep the lights on at home because of the town’s constant power outages. He found a solution inside his electric cars: their batteries.

A tinkerer who posts videos of his handbuilt vehicles on Youtube, Maguire devised a wiring system that lets him suck power out of them when they’re parked in the garage.

Now that the house and cars are connected, he can also use the batteries to store energy from his backyard solar panels, another power source that’s not totally reliable given Ireland’s weather.

“You have the light-bulb moment,” said the 41-year-old electrical engineer. “There’s a big battery in the car, so how about I use that?”

An even bigger light-bulb moment is happening for utilities and automakers, who want to use the batteries inside electric cars as storage for the entire public power grid.

The idea, known as “vehicle-to-grid,” is to someday have mils of drivers become mini electricity traders, charging up when rates are cheap and pumping energy back into the grid during peak hours or when the sun simply isn’t shining.

If it works – and it’s a big if – renewable energy could get much cheaper and more widely used.

“We really, really need storage in order to make better use of wind and solar power, and electric cars could provide it,’’ said Daniel Brenden, an analyst who studies the electricity market at BMI Research in London. “The potential is so huge.’’

Today, fewer than 1% of the world’s vehicles are electric, but by 2040 more than half of all new cars will run on the same juice as televisions, computers and hair dryers, according to estimates by Bloomberg New Energy Finance. Once cars and everything else are fed from the same source, they can share the same plumbing.

As it stands, energy generated by wind and solar farms often goes to waste because there’s nowhere to store it. South Australia solved the problem by investing an estimated US$80mil to US$90mil to build the world’s biggest lithium ion battery on the edge of the Outback. The result is a massive cluster of white boxes that is essentially a huge reservoir for electricity. Inside are the same batteries Tesla Inc uses in its cars.

But what if that reservoir was divided between mils of cars already on the road? That’s the vehicle-to-grid concept.

It’s promising because the newest electric vehicles can hold enough energy to power the average US home for several days. For most drivers, whose cars sit idle 90% of the time, sharing their batteries would make good use of a very under-utilised resource. (It’s like Airbnb, but with car parts instead of seldom-used apartments.)

For the utilities, borrowing people’s batteries would mean not having to build or buy them.

Sounds awesome. In the real world, though, there’s a tangle of complications.

Elaborate new computer networks would have to be built, carmakers and power companies would have to collaborate, and people would have to stop thinking of their cars as a private bubble.

The main practical problem is getting drivers to charge up when there’s a power surplus, and getting them to give back when the public grid has a deficit, all the while making sure people’s cars never run out of juice.

To get a sense of the difficulties, consider the struggle the world’s No. 1 seller of electric cars, Nissan Motor Co, has had convincing customers in Japan to try a simple system like the one Maguire jerry-rigged for himself at his home in the Irish countryside.

By allowing car batteries to serve as a residential power source, Nissan says its vehicleto-home service cuts utility bills by about US$40 per month.

Still, only about 7,000 car owners have adopted the system in the six years since it started, a tiny number compared with the 81,500 Leaf EVs that Nissan has sold so far in the country.

Declining to discuss any travails, a spokesman said the company is “very pleased” with its sales and sees growing consumer interest in the technology.

Meanwhile, Nissan is trying other experiments.

Last year, it partnered with Japan’s biggest utility, Tokyo Electric Power Co, to design a vehicle-to-grid system that takes the Maguire idea and ratchets-up the complexity.

A small test this winter showed how hard it is just to get people to charge their cars at the right time. (Selling power back to the grid is a separate can of worms.)

Nissan and the utility convinced 45 of their own employees to install home chargers and try monitoring electricity demand on weekends, using a smartphone app.

Even though volunteers got free shopping points on Amazon as a reward for buying power when there was glut, only about 10% succeeded.

The big takeaway was that, since most people aren’t home in the early afternoon, the system won’t really work until there are fueling stations all around town at places like the mall or the park. The company is looking at lots of different ways to boost participation, according to Yukio Shinoda, a Tokyo Electric manager who helped organize the trial.

Jonn Axsen, an associate professor at Simon Fraser University in Canada, who has studied vehicle-to-grid systems, says it’s unclear whether power companies will be able passon enough cost savings to convince car owners to cooperate.