Aviation alone is responsible for 3.5 percent of climate change, which is why in 2021 the Environmental Protection Agency issued a greenhouse gas emissions standard exclusive to aircraft. This move holds much promise: switching from fossil-fueled planes to electric planes can reduce CO2 emissions by as much as 88 percent.
What Is an Electric Plane?
Electric planes are aircraft powered not by jet fuel but by lithium-ion batteries, which can be recharged via solar energy, grid electricity and other methods. They can forego the use of fossil fuels, making for cleaner transportation.
The benefits of electric planes are obvious: “Running on electricity not only makes aviation more sustainable, but also drastically reduces noise pollution and carbon emissions produced by planes,” said Mogale Modisane, an engineer at ENGIE and representative of the United Nations World Energy Council. “Its motors are powered by battery packs that give it a quieter and smoother ride compared to its combustible counterparts.”
But as air taxis and eVTOLS take to the skies, the question of how companies plan to out-engineer electric aviation challenges — power, weight, energy density and range, to name a few — is still up in the air.
What are Electric Planes?
At their core, electric planes are aircraft powered by electricity rather than traditional jet fuel. While designs vary, most current models are outfitted with high-capacity rechargeable lithium-ion batteries and electric motors known for their zero-carbon-emission output. On a single charge, they can manage trips under 500 miles.
However, because of limitations with current battery technology, some companies are using alternative power sources such as hybrid and solar-power engines to develop sustainable propulsion systems and push the aviation industry to new heights.
How Do Electric Planes Work?
Electric planes work on a principle of electric propulsion.
Instead of using fuel-burning jet engines, electric motors drive propellers to generate thrust or rotors to generate lift — depending on the make, explained Ahmed Khan, a mechanical engineer and tech blogger at Fly That Drone and TechRandm.
Energy is stored in large lithium-ion batteries on-board, which may account for more than half of an aircraft’s weight. Lithium-ion batteries are the same ones that power our laptops, phones and electric cars. They can be charged in between trips while parked or in mid-flight via solar panels or regenerative systems powered by airflow.
How Far Can Electric Planes Fly?
As electric aviation is still in its infancy, it’s too early to pinpoint an average flight time or distance. Right now, companies are either just starting to conduct experimental test runs or working their way up to it.
Currently, the record for distance traveled is held by Solar Impulse’s Solar Impulse 2, which traveled over 5,000 miles non-stop from China to Hawaii during the round-the-world solar flight in 2015 and 2016.
Mark Tonkin, a first officer pilot for Atlas Air and a certified flight instructor, noted that, even in this early stage, many of the electric planes are being used to teach trainee pilots. Generally speaking, he estimates that most aircraft range to span 20 minutes to one hour of flight time, depending on environmental conditions.
“Regenerative and solar energy is not enough to operate the aircraft consistently,” Tonkin said, “and wind plays a large role in an aircraft’s ability, potentially reducing its range.”
Other factors that drag battery-powered aircraft include heat and payload.
“However, advances in battery technology and motor efficiency are expected to increase the range of electric aircraft significantly in the coming years,” Tonkin added, with some companies already developing hybrid-electric aircraft that can last up to 1,000 miles.
Types of Electric Planes
All-Electric Aircraft
All-electric aircraft are airplanes powered entirely by electric motors and batteries instead of traditional jet fuel. They have no direct carbon emissions and are less noisy than traditional planes, using electric propulsion to drive their propellers. All-electric aircraft are best suited for short-range flights.
Hybrid-Electric Aircraft
Hybrid-electric aircraft (HEA) use a combination of traditional jet engines, electric motors and batteries to deliver energy-efficient flights. HEAs will typically use electric motors for takeoff and landing and traditional engines during flight. A special gear system connects both electric and traditional engines, keeping the plane's propellers running no matter which engine provides power.
eVTOL
Electric vertical take-off and landing (eVTOL) aircraft are electric-powered vehicles that can take off, land and hover vertically. Primarily designed for air taxi services, logistics and emergency services, they feature no wings like a traditional aircraft. Instead, they rely on multiple propellers in multicopter or tiltrotor configuration for lift-off and flight.
Solar-Powered UAV
Solar-powered UAVs, often called “solar drones,” use photovoltaic panels to convert sunlight into electricity. This enables these autonomous systems to be in flight for extended periods. Solar-powered UAVs are lightweight and capable of high-altitude flights, making them ideal for surveillance applications.
Electric Plane Examples
Alice
Recording an eight-minute maiden voyage at an altitude of 3,500 feet, the world’s first all-electric commuter aircraft — named Alice — completed its first journey on September 27, 2022 at a flight test center in Washington. The slender, sharp-nosed twin prop jet is fully battery-powered and can seat nine passengers. And it produces zero emissions — a goal shared by virtually everyone in transportation technology.
Solar Impulse 2
The Solar Impulse 2 prioritizes efficiency, boasting a wingspan of 72 meters and over 17,000 solar cells while only weighing a little over two tons. This sustainable design is what made the first round-the-world solar flight possible in the Solar Impulse 2. During this unprecedented journey, pilots Bertrand Piccard and André Borschberg traversed over 25,000 miles and crossed the world’s two largest oceans during a span from 2015 to 2016.
Spirit of Innovation
With a top speed of 387 miles per hour, Rolls-Royce’s ‘Spirit of Innovation’ aircraft is the fastest electric plane in battery-powered aviation. It uses a 400-kilowatt electric powertrain — equivalent to that of a supercar — in tandem with a power-dense propulsion battery pack complete with 6,480 battery cells.
The Pelican Cargo
The Pelican Cargo is an autonomous, all-electric cargo plane with a 200-mile range and 400-pound capacity limit. It’s made by California-based startup Pyka, which initially produced fixed-wing aerial crop sprayers. In respect to payload, the Pelican Cargo ranks as one of the largest electric planes to have successfully taken flight.
The Wright Spirit
Developed by Wright Electric, this 4-engine, 100-passenger aircraft will be an electrified version of the airline’s pre-existing model, the BAe 146. With an airtime of one hour, the Wright Spirit is being designed to handle busy routes, such as London to Paris or San Francisco to Los Angeles, with plans for commercial takeoff in 2026.
Prosperity I
China-based tech startup AutoFlight holds the world record for longest distance traveled by an eVTOL in its aircraft Prosperity I, which flew 155 miles on a single charge. The aircraft can carry up to four passengers and one pilot. It was designed for short transfers, connecting proximal cities or airports. According to its website, the company predicts Prosperity I will be commercial flight-ready by 2025.
Alpha Electro
Alpha Electro was the first electric plane certified as airworthy by the Federal Aviation Administration, an accolade awarded to the 831-pound, battery-powered two-seater in 2018. Slovenia-based aircraft manufacturer Pipistrel created this model specifically for pilot training, combatting fuel and other associated costs for novice flyers by 70 percent. Newer models from Pipistrel include the Alpha Trainer and the Velis Electro.
PHASA-35
Designed to operate in the stratosphere for months at a time, the PHASA-35 is an ultralight solar UAV built for high-altitude missions above 66,000 feet. The aircraft is designed by BAE Systems and uses solar energy during the day and a battery storage at night to maintain continuous flights. PHASA-35 is engineered for surveillance, communications and environmental monitoring. PHASA-35 is engineered for surveillance, communications and environmental monitoring, providing an alternative solution to satellites.
RTX Hybrid-Electric Flight Demonstrator
RTX’s hybrid-electric flight demonstrator is an experimental hybrid-electric propulsion system. It is designed to test how hybrid propulsion can reduce fuel use during different phases of flight. Still in development, the aircraft features dual thermal engines, an electric motor and 200-kilowatt-hour battery in the hopes of advancing regional transport. The project aims to show a 30 percent improvement in fuel efficiency compared to current regional turboprops.
Are Electric Planes Practical?
It depends on how you look at it.
Applications imagined so far include air taxis, which are small commercial planes that transports riders short distances on demand to circumvent ground traffic congestion, as well as pilot training, crop spraying and cargo services.
Feature-wise, electric planes are quiet, quick to respond to weather changes, have superior handling in crosswinds and the ability to produce differential thrust in comparison to traditional combustion engines, according to engineering-oriented platform Lesics.
And, in terms of sustainability, electric planes are a zero-emission solution to decarbonizing air travel.
Electric aviation’s biggest hurdle, however, is balancing the energy density of a battery power source. Consider the fact that battery energy is more than 40 times heavier than jet fuel. The battery unit that powered Alice — widely considered the most successful electric plane flight to date — still added 8,000 pounds.
Essentially, it’s a snake eating its own tail. The heavier the aircraft, the less lift it can produce, which means it needs more power. However, in the case of battery-operated planes, adding power means piling on more batteries, which adds more weight. Improving battery technology is the key to electrifying the skies.
Other factors, like production, shouldn’t be overlooked either.
“Electrification, though low on carbon emissions, is not a totally environmentally friendly process — it still relies on fossil fuels, such as gas,” said Irina Tsukerman, a human rights lawyer who serves as a member of the American Bar Association’s Energy, Environment and Resources Section. “The environmental costs of mining lithium are high.”
Tsukerman noted that the countries on the forefront of developing and benefiting from this technology, like the United States and Europe, may not be the same ones physically mining lithium in their own backyard.
“This means that there is a high degree of dependency on countries, such as China, which is not known for environmentally friendly policies or safeguards,” she said. “Production of electric planes is very expensive, and the costs of operating are unaffordable for most users.”
Frequently Asked Questions
How far are we from electric planes?
Experts say it could take a decade or so before electric planes are ready for widespread commercial passenger use. But some airlines, like United Airlines, are pushing to electrify aircraft as early as 2026. And countries like Denmark and Sweden have promised fossil-fuel-free domestic flights by 2030.
How long do electric planes fly?
It’s still too early to determine an average flight distance for electric planes. As of now, the longest flight by an electric plane was completed by the Solar Impulse 2, which flew over 5,000 miles between China and Hawaii in 2015.
Will electric planes be cheaper?
Electric planes are expected to be cheaper as the technology improves. However, factors like battery weight and environmental costs during the production process could impact how effective and practical electric planes are in the future.
Are electric planes environmentally friendly?
Yes, electric plans are more environmentally friendly compared to regular jetliners. They produce no carbon emissions during flight and also have lower noise pollution levels. However, the battery manufacturing process does have high levels of emissions.
Will electric passenger planes replace jetliners?
Electric passenger planes are unlikely to replace jetliners in the near future. Although they offer zero emissions, current battery technology limits their range and power output, making them better suited for short-range commuter flights.
