Fuel falls from the sky
It’s long been the dream of technology buffs and futurists, but the self-charging electric car may not be too far down the road. A number of ‘perpetually-powered’ cars, as they are called, have been on show at annual events such as the World Solar Challenge for decades, with dozens of teams racing solar PV cars 3000 kms from Darwin to Adelaide.
But now, the concept is reaching the marketplace. Toyota, one of the world's biggest vehicle makers, is already building demonstration cars using high-efficiency solar cells — capable of converting 35 percent of the solar radiation landing on them into electricity — that can run 50 kms a day.
“The fuel is literally falling from the sky,” said Ned Ekins-Daukes, an associate professor at Australia’s University of NSW, adding that Toyota's own surveys suggest 70 percent of daily passenger car use could be covered by self-charging cars. “We're on the cusp here.”
Professor Ekins-Daukes said covering a roof and bonnet with solar cells can supply 20 kms of range a day, while layering the sides of a car with panels can add another third. Improving the drive efficiency of electric cars would extend the range further, with the Prius able to travel 17 kms on a single kilowatt-hour, while those driving from Darwin to Adelaide have been able to achieve twice that.
While the take-up of electric cars is still slow — although new data shows a tripling in annual sales in Australia alone, albeit to just 6,718 in 2019 — the long-anticipated demand surge is beginning. New models entering the market should also bring prices down, with analysts expecting price parity with combustion-engine cars by the mid-2020s if not sooner. And the appeal of self-charging or solar-powered vehicles will add to the allure of electric vehicles, which includes avoiding service station queues and fluctuating fuel prices.
Should self-charging vehicles enter the mass market, demand for charging stations would also be reduced, Professor Ekins-Daukes predicts. Likewise, the extra strain on a power grid already struggling to meet demand during heatwaves. And UNSW's Taha Rashidi found car owners would shell out an extra $2000 for an extra 30 kms of driving range per day from solar panels.
Along with cars, self-charging buses and trucks are obvious applications of the embedded PV, particularly if city transport authorities take the lead and set standards, Professor Ekins-Daukes said. However, the advancing solar technology means “pretty much anywhere you'd like to extract energy” will be possible, not least buildings where integrated PV are increasingly commonplace, he said.
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PHOTO Craig Abraham