In the week Swedish schoolgirl environmental campaigner Greta Thunberg set sail across the Atlantic for a UN climate change conference because flying would emit too much carbon, we ask just how far away are commercial electric planes, especially on short haul routes like between the Channels Islands and Jersey and the UK?
Last month’s Paris Airshow saw the launch of the world's first commercial all-electric passenger aircraft - albeit in prototype form. Israeli firm Eviation says the craft, called Alice, will carry nine passengers for up to 650 miles (1,040km) at 10,000ft (3,000m) at 276mph (440km/h) and is expected to enter service in two years. Eviation has already received its first orders from US regional airline Cape Air. Norway and Sweden are aiming to make short-haul flights in their airspace electric by 2040.
The future also looks reasonably bright for medium-range flights of up to about 1,500km. Unlike all-electric Alice, aircraft targeting this range would use a mix of conventional and electric power, enabling them to cut CO2 emissions significantly by switching on the electrical component of their propulsion at the key points in a flight.
Rolls-Royce, Airbus and Siemens are working on the E-Fan (above) X programme, which will have a two megawatt (2MW) electric motor mounted on a BAE 146 jet. It is set to fly in 2021.
Rolls-Royce's chief technology officer Paul Stein says: ‘The engineering is absolutely leading-edge and our investment in electrification is ramping up rapidly.’
United Technologies is working on a hybrid electric demonstrator designed to test a 1MW motor and sub-systems. The firm says it should provide fuel savings of at least 30%. It should fly in 2022 and is forecast to be ready for regional airliners by the mid-2020s.
Zunum Aero, backed by Boeing, is using an engine turbine from France's Safran to power an electric motor for a hybrid craft. EasyJet is working with Wright Electric, saying it will start using electric aircraft in its regular short-haul services by 2027.
Prospects for electric long-haul flights are not so rosy. While electrical motors, generators, power distribution and controls have advanced rapidly, battery technology has not. Even with batteries that are 30 times more efficient and energy-dense than today, it would only be possible to fly an A320 airliner for a fifth of its range with just half of its payload, says Airbus. The big problem is that 80% of the aviation industry's emissions come from passenger flights longer than 1,500km - a distance no electric airliner could yet fly.