Although automakers, led by Tesla (TSLA), have produced full EV fleets recently, aircraft manufacturers are still a long way from electrifying the US aviation sector.

According to energy experts, this makes the industry aim of reaching net zero emissions by 2050 all the more distant.

“Aviation is really hard to decarbonize,” Samantha Gross, director of energy security and climate initiative at the Brookings Institution, told Yahoo Finance. “You’re never going to see a battery-powered 737 [plane] because batteries are heavy.”

For this reason, the industry is developing several green energy options, such as sustainable fuels for longer-range, heavier aircraft. In the meantime, electric helicopters and small aircraft are also in the works.

Only a few US businesses have made significant progress toward electrifying air transport thus far. Large manufacturers, airlines, and automakers are investing in their initiatives.

A $1 billion deal was struck between United Airlines (UAL) and Archer Aviation (ACHR) a few years ago to buy up to 200 of the vertical takeoff and landing, or eVTOL, vehicles that the startup produces. The California-based business had a partnership with European automaker Stellantis (STLA) prior to the United acquisition.

“When I founded Archer, I knew from watching the EV industry that developing the capability to manufacture our aircraft at high volumes was perhaps the No. 1 enabler of our future success alongside the design and certification of the aircraft,” co-founder Adam Goldstein said during an earnings call earlier this year, elucidating the rationale behind the company’s decision to accept the automaker’s investment.

In the meantime, Santa Cruz, California-based Joby Aviation (JOBY) has received support from Toyota (TM) and Delta (DAL) Airlines. The eVTOLs developed by the firm can cover a distance of up to 100 miles on a single charge, or two round journeys from JFK Airport to central New York City. Within the framework of a larger deal with the US Department of Defense, the business has already given one of its planes to the US Air Force for training and testing.

An internal unit of French aircraft manufacturer Airbus (AIR.PA) is developing an electric air taxi prototype, with a target delivery date of the end of this decade.

Wisk Aero, an eVTOL startup based in Mountain View, California, was acquired by American aircraft manufacturer Boeing (BA) last year. In 2022, Boeing contributed $450 million to the business.

“Today’s startups are collecting information on how to fly one of these aircraft in an all-electric setting,” stated Dave Shilliday, vice president and general manager of Honeywell’s advanced air mobility (HON) division. The company produces interior parts and engines for both conventional and electric aircraft.

Although the Federal Aviation Administration has not yet given its full approval for the use of electric aircraft for commercial purposes in the US, Archer and Joby intend to introduce the vehicles for use in commerce in 2025.

Self-governing Aerial Taxis

Since 2010, Wisk has been developing a completely self-governing aerial taxi. With a range of up to 90 miles, the startup’s “Generation 6” vehicle can accommodate four people together with their carry-on bags. Humans on the ground supervise the flights even though there are no pilots on board.

Wisk and the City of Sugar Land, Texas, have announced a partnership to build the necessary infrastructure for Wisk to eventually operate autonomous air taxis throughout the Greater Houston area.

According to the company, its objective is to make the service accessible to everyone, including professionals and college students. According to a spokeswoman, “a trip in Wisk’s aircraft will be comparable to a basic ride-share service cost per mile.”

Although the date of Generation 6’s commercial flight certification is unknown, the business has already completed almost 1,700 test flights using several aircraft generations.

Hybrid Aircraft

The airplane industry is transitioning to electric power gradually, just like the auto sector has adopted hybrid automobiles as a transitional stage before going fully electric.

One such is the 15-foot-long hybrid eVTOL that Ontario, Canada-based Horizon Aircraft (HOVR) is now developing, with the first goal being municipal use and emergency scenarios such as hospital transports.

According to Brandon Robinson, co-founder and CEO of Horizon Aircraft, “consider it [the hybrid] as a very practical bridge to a future when all-electric aircraft actually make a lot more sense.”

In the near future, more hybrid solutions will be driven by cost-effectiveness, according to the former Canadian fighter pilot.

“When you burn less fuel per unit mile, you not only save yourself costs, but also, from a sustainable aviation perspective, you produce less hydrocarbons,” he added.

Sustainable Fuel

As long-haul electric flights are mostly limited by battery weight, the industry is currently shifting its focus to clean jet fuels for large aircraft.

The first transatlantic flight from London to New York City using 100% sustainable aviation fuel (SAF) that isn’t sourced from petroleum was tested by Virgin Atlantic last year, making history.

“The world will always assume something can’t be done … until you do it,” read a blog post by founder Sir Richard Branson. “This flight today shows that sustainable jet fuel can be used as a drop-in replacement for jet fuel — and it is the only viable solution for decarbonising long-haul flights.”

By 2030, the International Civil Aviation Organization of the UN hopes to raise the total SAF pool from its current levels of less than 1% to 5%.

Gavin Towler, Honeywell’s chief sustainability officer, told Yahoo Finance, “We think that’s very achievable.” Startups and oil corporations can license the company’s SAF technologies for chemical facilities.

Although there are many techniques to make sustainable aviation fuels, three have come to be recognized as leaders in the field. Feedstock is used by one of them. The other is associated with ethanol, a component of gasoline mixtures. The third entails producing aircraft fuel by combining carbon dioxide and hydrogen.

According to Ramanan Krishnamoorti, vice president for energy and innovation at the University of Houston, having a single standard for SAFs across the board would hasten the transition to sustainability, as reported by Yahoo Finance.

“Price is the biggest challenge that we face today,” he said. “The second is also having the same quality of the sustainable aviation fuel across the world.”