Steve Wright, associate professor of aerospace engineering at the University of the West of England Everybody is talking about electric Vertical Take-Off and Landing vehicles (eVTOLs), also known as flying taxis. There is going to be disappointment - the technology is not moving as quickly as some companies might hope - but they will start to appear over our heads in the 2020s. There are all sorts of compromises that need to be made to get the efficiency as high as possible, but frankly companies aren't going to solve the energy-density issue. We are spoiled rotten by hydrocarbon fuel, which has about 40MJ per kilogram, but the best batteries at the moment have 1MJ. Even if we double or triple energy density in batteries over the next 10 years, we're still a long way away from aviation fuel. If we get to one-hour flights by 2030, I'd be really surprised.
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