The development of all-electric aircraft continues at full speed. The Eviation Alice prototype electric plane made its first 8-minute flight, and other models, such as Heart Aerospace’s ES-30, are expected to hit the market in the coming years. However, all these models are designed for the transport of up to 30 passengers and for short-haul flights.

Eviation Alice, for example, can carry only two crew and nine passengers for a distance of 463 kilometers, and the electric model EU-30, although designed to carry up to 30 passengers, has a flight range of only 200 km.

Larger all-electric aircraft are needed to truly reduce greenhouse gas emissions and mitigate the effects of climate change. It is noteworthy that large airplanes account for more than 75 percent of greenhouse gas emissions in aviation, and these emissions increase when air transportation’s annual growth of 4-5 percent is taken into account.

But a NASA-sponsored research team has begun developing an all-electric version of the N3-X aircraft that can carry 330 passengers. Scheduled to launch in 2040, the N3-X electric aircraft features an aerodynamic hybrid wing-fuselage fuselage and energy-efficient EPS. But it will still rely on twin-turbo engines burning jet fuel to power the EPS.

The main problem with fully electrifying the N3-X, and large aircraft in general, is the enormous energy requirements for take-off propulsion, which requires around 25 megawatts of power. For comparison, the modern Boeing 787-8, a partially electric aircraft, achieved a maximum power of about 1 MW from renewable sources (the rest of the power required for takeoff comes from burning jet fuel).

“In other words, we need 25-30 times more energy to fully electrify a partially electric aircraft, and almost all of that required power is for take-off,” says Mona Ghassemi, associate professor and director of ZEROES (Zero Emissions).

To help meet these power needs, his team proposes replacing the N3-X’s two turbo electric motors with four electrochemical energy units (EEUs) containing batteries, fuel cells and supercapacitors. They developed several different EPS designs for takeoff, where all power goes to propulsion. Theoretically, with sufficiently powerful batteries, this charge should be enough to blow up the N3-X with electricity alone.

The researchers analyzed three EPS designs under normal conditions, as well as scenarios where one of the power system components failed. Their results show that the two designs can be implemented in real life even if one EEU fails in flight. It is noteworthy that modern battery technology lags far behind what is needed in these all-electric designs. But Ghasemi does not stop.

“With future developments in lithium-air and lithium-sulfur batteries, the specific energy required for the envisioned wide-body all-electric aircraft can be achieved within the next 25 years,” he says. “However, another promising solution can be achieved sooner – compact fusion reactors.”

Whether the airplanes of the future will run on batteries or compact fusion technology, additional infrastructure is needed to meet the enormous energy demands of larger all-electric airplanes. This includes electric drives and motors, EEUs, circuit breakers, cables and converters that can withstand high voltages and harsh aerospace conditions (eg low pressure, high humidity and high temperatures). Source