Reducing carbon emissions from commercial aircraft is hard. Unlike cars, trucks, and buses, where the extra weight of batteries is more or less irrelevant, weight is absolutely critical when it comes to planes. If 747s were made of cast iron, the history of flight would be short indeed.
It’s simple physics. According to Jet Pack Aviation, jet fuel has an energy density of 9.6 kWh per liter. By comparison, the battery in a Tesla Model 3 has an energy density of 207 wH per kilogram. That means jet fuel has about 50 times as much energy by weight that the best batteries available today. That’s not the end of the story, of course. Electric motors are far more efficient than jet engines, so that narrows the advantage a bit. Even so, a thousand pounds of jet fuel yields about 14 times more power than a thousand pounds of batteries.
What that means is that electric aircraft are not going to be shuttling 500 people non-stop across the Pacific Ocean any time soon. However, they may be be able to fly a dozen or more over short distances fairly soon. Swedish electric airplane startup Heart Aerospace says its ES-19 will be ready to begin commercial service on flights of 250 miles or less by 2026.
Unites Airlines, through its venture capital subsidiary, has agreed to purchase 100 ES-19 electric aircraft from Heart and anticipates having them transporting paying passengers before the end of the decade. Mesa Airlines, a subsidiary of United, has also signed up for 100 of the electric airplanes. Heart has also attracted investments from Bill Gates’ Breakthrough Energy Ventures.
In a press release, United vice president Michael Leskinen says, “Breakthrough Energy Ventures is the leading voice of investors who are supporting clean-energy technology creation. We share their view that we have to build companies who have real potential to change how industries operate and, in our case, that means investing in companies like Heart Aerospace who are developing a viable electric airliner. We recognize that customers want even more ownership of their own carbon emissions footprint. We’re proud to partner with Mesa Air Group to bring electric aircraft to our customers earlier than any other US airline. Mesa’s long serving CEO, Jonathan Ornstein has shown visionary leadership in the field of electric-powered flight.”
What’s the big deal about small, electric aircraft? First, their cost of operation is considerably lower than a conventional airplane. Not only is the cost of electricity less than the cost of fuel, maintenance costs will be lower as well. Second, small airplanes can access smaller airports with lower landing fees to bring passengers to larger transportation hubs. In a sense, lower emissions are just part of the story. Expanding air travel to include customers who find flying too inconvenient today can be a major boost to revenue.
United currently operates 100 short-haul routes that could be serviced by the ES-19. “We expect the short-haul regional air travel market to play a key role in the evolution of the electric aircraft. As battery technology improves, larger-gauge aircraft should become viable but we’re not going to wait to begin the journey,” Leskinen says. “That’s why we’re looking forward to beginning our work with Heart, so that, together, we can scale the availability of electric airliners and use them for passenger flights within the next five years.”
Carmichael Roberts of Breakthrough Energy Ventures adds, “Aviation is such a critical piece of our global economy. At the same time, it’s a major source of carbon emissions and one of the most difficult sectors to decarbonize. We believe electric aircraft can be transformational in reducing the emissions of the industry, and enable low cost, quiet, and clean regional travel on a broad scale. Heart’s visionary team is developing an aircraft around its proprietary electric motor technology that will allow airlines to operate at a fraction of the cost of today and has the potential to change the way we fly.”
With a capacity of 19 passengers, the ES-19 is significantly larger than many other electric airplanes for commercial use, including the 9-passenger Alice from Eviation that Zachary told us about a few days ago. For passengers, electric airplanes hold the promise of cheaper fares and a much quieter trip than they are accustomed to on today’s short-haul turbo-prop aircraft. Zero direct emissions while in flight is just an added bonus.
The FAA will make sure these new aircraft are fully airworthy before the first paying customers climb aboard. United also has a vested interest in seeing to it that its passengers get from Point A to Point B safely. In 2016, the Solar Impulse team predicted the first commercial aircraft powered by electricity would take flight within ten years. That prediction may turn out to be eerily prescient.