Solar EV charging option looms large

EV drivers increasingly want to power their vehicle with solar energy.

Electric Vehicle Council CEO Behyad Jafari. Picture: Monique Harmer

Drivers need a different mindset when charging their electric vehicles using solar energy.

That’s the view of the Electric Vehicle Council, which says it’s increasingly possible to run an EV on solar and green energy and avoid fossil fuel power if people are not emptying their battery ­before charging it again.

One of the main arguments of EV opponents is the cars’ dependence on electricity generated from coal and gas-fired power stations. However, according to the council’s consumer attitudes survey, 55 per cent of respondents say they would power their electric vehicles from solar panels.

CEO Behyad Jafari said most consumers wanted to charge from a green source whether it was rooftop solar panels, a home battery or from buying green energy off the grid.

“There’s a close link between people who want solar panels, batteries and electric vehicles,” Mr Jafari said.

Charging an EV at home entirely from solar has its limitations, but it’s doable for many. It also needs a change in mindset.

Mr Jafari said the concept of fuelling up from 0 to 100 per cent capacity was “petrol station mentality”; the charging regime around an EV at home was different. “You might bring your car home, plug it in at 30 per cent and go away,” he said. “It might take two hours to top it up to where you need it to be.” That might not be at 100 per cent, he said.

Mr Jafari said charging an EV was a bit like charging a mobile phone.

“If you’re charging your car once a fortnight, you might say ‘I’ve got a lot of excess solar right now so it’s a great time to charge my car because I’ll pay absolutely zero for it’.”

There are three levels of charging. Plug-in trickle chargers deliver about 2kW of power. A single phase wallbox charger at home delivers 7kW, while a three-phase version offers about 22kW. Power and charging times also depend on the car battery.

A Volvo XC60 charges in Reading, west of London. Picture: AFP

Mr Jafari said the third level – fast-charging units – weren’t really for home use: “Fast-charging ones offer between 50kW and 350kW and would usually be more in public locations. You wouldn’t build those at home.”

According to the council’s data, the overwhelming amount of EV charging is home; EV drivers use public charging facilities about 5 per cent of the time.

Mick Fell, general manager of solar energy solutions provider Qcells & Arcstream Solutions, said using solar to power EV was perfect for those who spent most time at home – “because your car is sitting there and you’re going, ‘how do I get free energy?’ and you just plug it in It’ll work. It’s fantastic.”

He said the average household solar panel installation drew 6.6kW and generated about 20kWh a day. That was based on an installation of 15-20 panels. He said in the middle of a day an average solar energy system could provide the equivalent power used for an EV battery – at other times you would depend on extra power from the grid or a solar battery system.

Households could install larger solar systems but they were limited by the capability of inverters – typically just over 9kW.

“Depending on what car you buy, that could be as little as 20 per cent of a Tesla Model S, or it could be 50 per cent of a Nissan Leaf in terms of the size of the battery,” Mr Jafari said.

Mr Jafari said people buying EV needed to investigate the car’s charging capability and the options for home charging.

“We know cars spend some 96 per cent of their time stationary, and that’s when they can be charging,” he said.