MIAMI – Air travel and air freight generate a significant portion of global carbon emissions, and more people are flying every day. The International Air Transport Association (IATA) estimated in 2016 that air traffic would double by 2035, potentially setting the industry on track to become the largest polluter across all industries.

As a result, designers and engineers also have an opportunity to significantly reduce carbon emissions by creating planes that don’t rely on fossil fuels.

New electric airplanes, powered by battery-driven electric powertrains, could help reduce or fully eliminate the emissions produced by air travel and shipping. Many experimental electric commercial airplanes are in development, and major aircraft manufacturers are investing in electric airplane technology.

Major barriers, however, mean the technology isn’t completely practical yet. In light of today’s first electric aircraft landing at Amsterdam Schipol Airport (AMS), we look at when the experts believe electric airplanes will become mainstream — and the challenges engineers will have to overcome to make the technology practical.

Vlucht NLR pipistrel boven omgeving Rotterdam. Photo: NLR

Why We Aren’t Seeing Electric Commercial Airplanes Yet

Despite growing demand for electric airplanes and investment from major aircraft manufacturers, significant design challenges have slowed adoption.

These new electric designs also need to meet the high demands of aviation engineering, including requirements for size, weight, hermeticity, and ruggedness. Size and weight have proven particularly challenging for aviation engineers.

Despite major strides in battery technology over the past few years, lithium-ion batteries remain both heavy and bulky. A battery large enough to produce power comparable to current jumbo jet engines, for example, would weigh around 1.2 million tons.

Most flights are short, less than 500 miles on average. Even these short-distance flights, however, require enough power to make current batteries impractical.

As a result, most manufacturers believe electric airplanes will remain impractical for some time. Boeing, for example, estimates that the industry is several decades away from producing a fully electric jumbo jet. Others are more optimistic. Investment bank UBS, for example, estimates that a full quarter of the aviation industry will be hybrid or electric by 2035.

Before jumbo jets with electric powertrains become reality, it’s likely that the industry will take smaller steps that help to mitigate the carbon footprint of aviation. Alternatives, like solar-powered aircraft and light electric planes, small enough to be powered by existing battery technology, will likely be essential in this transformation.

Image: Nasa

NASA Testing May Pave the Way for New Electric Planes

NASA, which has been working on electric aircraft propulsion for much of the past decade, anticipates a quicker timeline than the one expected by Boeing. The agency, in line with the Biden administration’s goal of cutting American emissions to net-zero by the end of the decade, hopes to phase in electric commercial flight for U.S. passengers by the “mid-2030s.”

To this end, the agency is actively recruiting private companies to help develop electric aircraft powertrains. In February, the agency announced that it intended to award contracts for work on experimental electric aircraft powertrains.

The demonstration tests of these powertrains will be overseen by NASA’s Armstrong Flight Research Center — one of the agency’s most important aeronautical research sites.

The U.S. military is also likely to play a significant role in the future of electric aircraft. In February 2021, the Air Force officially began its search for “flying taxis” — unmanned, vertical takeoff and landing (VTOL) aircraft that can move people and equipment around the battlefield. The project, “Agility Prime,” aims to purchase a number of these taxis by 2023 for testing.

NASA, again, may play a key role in the development of this technology. In September, the agency began joint testing of a new electric VTOL craft with electric aircraft manufacturer Joby. This is the first round of testing for the air taxi. The test team plans on capturing data on the vehicle’s movement, communications, and noise while in flight.

These hypothetical aircraft will likely have to be rugged and may need to meet existing standards on aircraft electric equipment, like the MIL-STD-704 standard for aircraft power interfaces. This could be good news for the future of the technology — existing military standards could help ensure more robust and practical aircraft by the time the taxis are ready for civilian use.

Electra’s first commercial product is designed to carry up to seven passengers and a pilot as far as 500 miles. It will serve urban and regional air mobility markets, sustainability-focused airline operations, “middle mile” cargo logistics, and air ambulance services. Image: Electra

Breakthroughs in Electric Plane Design

Small companies have also made major strides in light electric aircraft over the past few years.

For example, aerospace startup Skydweller Aero is currently preparing to test an autonomous aircraft that will fly for 90 days, powered entirely by solar energy. The craft will build on previous milestones in solar aircraft, like the Solar Impulse 2, which circumnavigated the Earth in 2016. Like new solar cars, these aircraft provide pilots with an opportunity to take advantage of recent developments in solar technology.

In 2020, Slovenian manufacturer Pipistrel began selling the Alpha Elektro, “the first electric aircraft certified as airworthy by the Federal Aviation Administration (FAA).”

The plane is extraordinarily light, weighing just 811 pounds (368 kilograms), and is powered by a 21 kWh battery pack.

That limited weight comes with a price — the company advertises the plane as having an endurance of just 60 minutes, plus an additional 30 minutes of reserve. The plane, however, represents a major milestone and will help to pave the way for future FAA-certified electric aircraft.

Other small electric aircraft are on the way. Aircraft manufacturer Electra plans to begin full-scale testing of a new eight-seat hybrid electric short take-off and landing (eSTOL) craft. Another eSTOL manufacturer, Airflow, recently entered into a contract to supply 50 airplanes to Ravn Alaska. These planes are expected to go into service in 2025.

DHL Express plans to add 12 of Eviation’s new Alice all-electric aircraft to its fleet from 2024. Photo: Eviation

When Will Electric Commercial Airplanes Enter the Mainstream?

These small planes likely represent the near future of electric aircraft. Early victories here, backed by major organizations like NASA and the U.S. military, will help to pave the way for larger planes — and eventually, possibly even all-electric jumbo jets.

The adoption of electric aircraft will have major positive effects on aviation, primarily by reducing the carbon footprint of air travel and air freight.

The electrification of air travel will not happen quickly, however. Even the pivot to lightweight electric aircraft has been turbulent. Uber sold off its aviation division to manufacturer Joby in late 2020, and aircraft maker Eviation made headlines in January 2020 when one of its experimental electric airplanes caught fire on the runway.

While progress has been slow, industry observers should expect major strides in electric aircraft development over the next few years. Even the more optimistic forecasts for the electrification of air travel, like NASA’s 2030 goal for a phase-in of electric commercial airplanes, are not unrealistic.

Article written by technology journalist Emily Newton. She is Editor-in-Chief of Revolutionized, an online magazine exploring the latest innovations. Featured image: eViation Alice in Paris Le Bourget Air Show in on June 16, 2019, photo © Jean-Marie Liot / eviation