Battery technology has improved from lead-acid hydride

Tag: Charging Car Battery

Battery technology has improved, from lead-acid tonickel-metal-hydride to lithium-ion. Phones and laptops usereasonably safe cells that give reliable service for years. Yetelectric-car converts are more than just enthusiasticproselytisers. Take Riva's G-Wiz, which uses a legislative loopholeto be classed as a quadricycle and thus avoid any form of crashtesting; often bought as a second or third car to beat London'scongestion charge, its owners scream blue murder if you questionthe efficacy of their not very green or crash-safe jalopy. Indeedwhenever I write about electric cars (EVs), I'm accused of stealingideas, not being supportive, being in league with big oil, big carmakers and probably Ming the Merciless, Emperor of Mongo too. Yetbattery technology is merely a carrier system, and not a veryefficient one. The energy density of even the best is still verylow compared to petrol or diesel, and advanced battery packs arestill massively expensive.

Current poster boy for the EV industry is the Tesla sports car. Inspite of the hype, just one of these £50,000, LotusElise-based roadsters has been delivered. Last I heard, thetwo-speed transmission that allows the ambitious long-range,long-life, high-performance claims is good for only a few thousandmiles, so the first cars will have a single-speed transmission thatwill be changed under warranty when the company works out a newsystem, along with new power electronics and cooling; it's a bitlike having your new car delivered with a lawnmower engine and anote promising a high-tech turbodiesel as soon as they've inventedone.

Tune in and plug in, says the EV industry, but there's a collectiveblindness about what's behind the plug socket. Where does theelectricity come from? Tesla's website makes some bold claims, butin US full-cycle efficiency terms it returns an equivalent of about44.4mpg; the hybrid Toyota Prius returns 45.9mpg. Electricity isnot a carbon-free source of energy; in the UK, almost 75 per centis generated by burning fossil fuels. The King report found thatwith the UK's current generation mix, pure electric cars couldoperate at the equivalent of about 80 grammes of carbon dioxide(CO2) per kilometre, not much less than VW's Polo BlueMotionturbodiesel, which will carry four adults to the ends of the earthat 99g/km.

But you can charge cars with off-peak electricity, claims the EVindustry. Well, I'm sorry, but only a few of us could. Europe andthe US have similar off-peak capacity for a million cars eachcharging 8kWhrs per night. After that, high-carbon generation comeson stream. If we want an pure electric future we might have toaccept a lot more radioactive waste.