He made the ambitious call during his ‘New Deal’ speech, setting out plans to “rebuild Britain and fuel economic recovery” after the coronavirus pandemic.
“As part of our mission to reach ‘net-zero’ CO2 emissions by 2050, we should set ourselves the goal now of producing the world’s first zero emission long haul passenger plane,” he said. “Jet Zero, let’s do it.”
People hoping for a quick and easy solution to aviation emissions will be disappointed, however, as the technology is far from ready. Electric planes have flown in the UK and abroad, but initial projects are based around small passenger numbers and relatively short regional journeys. The Eviation Alice, for example, has nine seats and a forecast range of 1,000km.
Other efforts have failed to make substantial progress towards zero-emission flight. Airbus and Rolls-Royce’s E-Fan X project, which would have initially used one electric motor before potentially electrifying further, was recently cancelled.
Energy density is the main challenge for zero emission flight. Hydrocarbon fuels store many-times more energy per weight compared to the best batteries, making them much more suitable for large planes for the time being.
Carbon neutral flights are a long way off, wrote aerospace expert Steve Wright from the University of the West of England in Professional Engineering earlier this year: “Without an absolutely astonishing physics breakthrough, we can’t expect even a regional electric jet until about 2035. I don’t expect the first electric transatlantic passenger flight until about 2050.
“The shame about hydrogen fuel cells is they’ve got more efficiency but about the same level of complexity as conventional internal combustion engines, while current biofuels are almost more environmentally damaging than fossil fuels, thanks to deforestation and palm oil growth.”
Other ‘green’ and engineering-focused measures in the prime minister’s speech included announcements on battery ‘gigafactories’, electric vehicle supply chains and carbon capture.
“Net zero is an extremely tough but necessary target, and the future of the UK’s decarbonisation and path to net zero is contingent on key decisions made by the government during this parliament,” said Sir Jim McDonald, president of the Royal Academy of Engineering. “Three decades is a very short time to completely renew, upgrade, install and secure entire parts of the UK’s national infrastructure but if government is willing to take a truly holistic view of the system, then the engineering community stands ready to deliver on the promise and potential of decarbonisation.”
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.