Not an electric airliner (Image from Wikipedia) |
There is a huge problem with making an electric airliner (as opposed to a very lightweight, short range, small electric plane). Kerosene - aviation fuel - is brilliant at packing in energy. Against a conventional lithium ion battery, kerosene stores away around 100 times as much energy per unit weight. So to replace, say, 50 tonnes of fuel would require 5,000 tonnes of batteries.
Don't get me wrong. Battery technology is improving all the time - and that ratio will get significantly better. But the 10 year timescale that Easyjet was talking about seems impossibly short to achieve that kind of improvement in energy density. It may be possible eventually, but we're talking a revolutionary technology that we don't have a clue about at the moment, not a simple factor of two or three improvement as may well be possible with current technologies. That just wouldn't make for good enough batteries to power airliners.
Cars are different, of course. I love electric cars. My dream car has gone from being an Aston Martin to a Tesla. But there are a couple of things to be aware of in making the jump from cars to planes. One is that it takes vastly more energy to get a 100 tonne aircraft up into the sky (and keep it there) than to move a car along the road. The other is that when they publish range for electric cars, it's very variable due to, for example, ambient temperature. You might find yourself with 100 miles less range than you expected. That would be decidedly embarrassing at 30,000 feet - so you would need far more spare capacity than in a car.
The other big drawback to this whole idea is that even its proponents suggest it would only work for short flights - but high speed rail is increasingly making those unattractive. It's like making a better gas light around the time when electric lights are starting to become common.
So, I'm afraid, the verdict is that this is pure greenwash - it's PR not progress.
Comments
Post a Comment