What are electric planes?
Electric planes, or electric aircraft, are powered by electricity instead of aviation fuel. There are many ways that electricity can be provided to the plane, including batteries. Electric motors typically drive propellers or turbines that allow a plane to fly. Planes, conventionally, have an enormous environmental impact. Electric planes have great potential to help cut down on the environmental cost by creating fewer emissions.
How does the technology of electric planes work?
Simply put, electric planes use batteries to power an electric motor. The motor turns the electric power into mechanical energy. Electric batteries have a charge that powers the motor, which spins when magnetic forces pull on the rotor.
An electric propulsion system also contains components like motor controller hardware or software, gearboxes, and cooling systems. Electric planes may have a variety of off-board power supplies, ensuring that they have the power they need without keeping all of it onboard, such as solar cells.
There are also hybrid electric planes in research and development, whereby an electric motor is combined with a conventional engine. And there may be another source of thrust or a power boost to the propulsion system during certain flight stages.
Are there different types of electric planes?
Electric vertical take-off and landing planes, or eVTOLs, use electric power to hover, take off, and land vertically. Electric helicopters use similar technology.
Urban Air Mobility (UAM) refers to the use of aircraft, such as drones, for transportation within urban areas. The technology is being developed and tested to safely integrate these aircraft into the national airspace for various purposes including transportation of people and cargo.
Small flying taxis are close to what some may have thought of as flying cars once upon a time. Electric air taxis might look slightly different from conventional fixed-wing craft, but they work similarly to other electric planes. Electric motors replace jet engines and often feature vertical take-off and landing technology with rotating wings and/or rotors instead of propellers.
Passenger drones are somewhat similar, flying passengers using electric power, but autonomously. Most use vertical take-off and landing technology. They join other classes of autonomous electric vehicles.
Electric cargo planes are a popular concept, perhaps because moving cargo is an easier first step than moving people. That said, these electric planes do need to be large and powerful enough to make cargo movement worthwhile.
Small, mid-size, and full-sized electric passenger planes work similarly but with the necessity of moving people rather than performing deliveries.
Are commercial electric planes already a reality?
Rolls-Royce’s electric plane, ACCEL, or Spirit of Innovation, had a test flight in 2021, reaching a top speed of 555.9 km/h over three kilometers. The aircraft was propelled on its record-breaking runs by a 400kW electric powertrain and a power-dense propulsion battery pack.
Boeing tested an electric passenger air vehicle, or passenger drone, in 2019. The prototype completed a controlled takeoff and hovered momentarily before landing.
Airbus’ E-Fan 1.1 was the first electric plane to cross the English Channel in 2015. It is a light, two-seat craft powered by lithium-ion batteries and two electric motors. In 2017, they launched the E-Fan X demonstrator program with Rolls Royce to test more technologies, a program which ended in 2020.
Ampaire’s Electric EEL, a modified three-passenger Cessna 337 Skymaster, completed a 341-mile test flight in 2020 and a record 1,135 miles across the USA in 2022. The company says the EEL demonstrated fuel savings of up to 40 percent compared to a standard Cessna Skymaster. Earlier in the year, Ampaire also started ground-power runs with the Eco Caravan regional aircraft designed for commercial use.
Are we far from having private electric jets?
Some companies are looking at jet aircraft powered by electricity. For example, Wright Electric is working on a 100-seat fully-electric regional jet that could take off starting in 2026. The Wright Spirit is a conversion of the BAe 146 regional jet, destined for one-hour flights.
Most of the electric planes in research and development right now may be well-suited to the needs a private jet usually fills. They are small and able to make shorter flights. They may be slower, but as technology improves, electric passenger plans and private jets may be nearer than one might think.
How will this tech impact the future of commercial air travel?
United, the third-largest carrier in the U.S. expects that electric planes will be a crucial part of its future, potentially impacting commercial air travel in numerous ways. Their plan is not to replace large-capacity jets with electric planes but instead focus on regional service. They are also exploring the use of eVTOL technology for local transport.
Instead of switching frequent flyers over to electric aircraft, the company is targeting a new market – people who would typically drive for shorter trips. Currently, less than one percent of travelers making a 250-mile trip choose to fly.
United says that electric planes will bring new services to small cities or provide a greater frequency of service. People can fly in and out in one day instead of driving over multiple days. They expect initial service to small cities with 30 passenger aircraft.
What are the benefits of using electric planes commercially?
Electric planes offer the potential for significant cost savings. Fuel costs are a large part of operations for aviation companies, and these can be variable costs. As fuel costs increase, so do flight costs for passengers. People may be less likely to fly when ticket prices rise due to fuel costs,which affects the bottom line. Cargo companies, too, must charge clients more when fuel costs rise.
Another critical benefit is noise reduction. Travelers who have taken a red-eye know about airplane noise restrictions around airports, where noise reduction programs are in place to protect residents, passengers and aviation staff alike. Noise pollution is a problem that impacts air traffic and the viability of local airports.
Conversely, electric aviation is much quieter compared to jet and turboprop aviation. This means planes can fly later at night, land in more densely populated areas, and contribute to a reduction in aviation-produced noise pollution overall.
Finally, electric planes have some advantages that may prove to be more reliable in time than their conventional counterparts. Electric motors are far more straightforward than fuel combustion engines. Maintenance is a large part of aviation costs, where an issue with one component can ground a plane indefinitely. Electric planes may have fewer parts subject to wear and tear, potentially reducing maintenance costs and downtime.
What is the impact on the climate?
Airplanes, conventionally, are not great for the environment. As a Rolling Stone article on making airplanes climate friendly states, planes produce about 2.4 percent of annual greenhouse pollution and could soon represent one-sixth of the world’s remaining carbon budget.
Conventional airplanes also leave behind contrails and cirrus formations that keep more heat in the atmosphere, making their warming footprint larger than their carbon footprint. Electric planes do not create the same kind of pollution and emissions. A Skies Magazine article notes that electric planes with current battery technology could help fight against global aviation emissions. Even better, as battery densities improve, they could eliminate 33 percent of the total aviation emissions caused by flights under 1,300 km (about 800 miles).
What are the drawbacks?
While there are clearly many potential benefits to electric planes, there are drawbacks and headwinds for continued commercialization.
Flying through the air requires a lot of energy, so airplane fuel requires high energy density. Presently, the size and weight of current battery technology make electric propulsion a challenge for larger aircraft in particular.
What is the current state of commercial electric planes?
The Alice flight
In September 2022, Eviation Aircraft launched the nine-seat Alice from Moses Lake, Washington, traveling for eight minutes at 3,500 feet. Eviation expects several more years for flight tests and certification, and thus Alice might not be commercially viable until 2027.
Do planes need a battery breakthrough?
With current battery technology, it’s challenging to electrify anything other than a commuter aircraft. According to ICCT, a regional, narrow-body and wide-body aircraft would require six times, nine times, and 20 times the battery capacity of today’s capabilities, respectively.
Why is the progress of battery tech so significant?
ICCT research also shows that from 1991 to 2015, the specific energy and energy density of lithium-ion batteries improved by a factor of three. If today’s batteries progress at the same rate — three times better in 25 years — it will be 2090 before the largest, wide-body aircraft can be electrified. How battery technology evolves will greatly impact the trajectory of the commercial electric plane industry far into the future.
How does energy density factor in?
Today’s batteries, including Amprius’s silicon nanowire anode batteries, are highly energy dense. The more energy-dense a battery is, the more power is packed into each cell. Small, energy-dense batteries are needed to power electric planes without making them too heavy to fly.