Plugged In and Taking Off: Electric Planes Hit the Skies

Jet fuel powers the aviation industry, which fosters interconnectivity on a global scale. However, the high greenhouse gas emissions from conventional fossil-fuel aircraft are unconducive to modern climate change goals. Aircrafts release both carbon dioxide and nitrogen oxides—greenhouse gasses that act like atmospheric blankets to trap heat. In total, aircraft fossil fuel emissions are responsible for nearly four percent of all human-driven climate change contributors. While this may seem low, the impacts of greenhouse gas emissions in aviation are more difficult to mitigate because they occur higher in the atmosphere. 

However, this could one day change. Across the globe, an electric revolution is unfolding. Considering the fast-rising popularity of electric vehicles, many entrepreneurs and engineers have turned to the skies in hopes of cutting emissions using similar technologies. While conventional planes rely on fuel-guzzling engines to power their flights, electric aircraft are powered by batteries and use an electric motor to spin a propeller. The introduction of electric planes could pave the way for a future where air travel is not synonymous with greenhouse gas emissions.

Electric power was first employed in aviation in the 19th century when it was used to fly hot air balloons. However, after this early breakthrough, the use of electricity to power aircraft remained extremely uncommon until the 1970s, when a number of small electric aircraft projects began to take shape. Engineers Robert Boucher and Paul MacCready pioneered the use of electric motors in small model planes, further contributing to the development of fully electric planes. In these motors, an electric current in coils wrapped around a magnet switches its polarity, creating a tug-of-war that continuously spins the motor and the propeller. Boucher and MacCready produced the manned solar-powered plane Solar Challenger, which made a fully electric flight across the English Channel in 1979. Throughout the remainder of the century, engineers developed numerous other solar-powered planes and drones.

In the 2010s, lithium-ion batteries largely replaced inefficient lead batteries due to widespread climate concerns. This concern also caused the formation of a number of startups dedicated to electric aviation, such as Pipistrel and Eviation. Commercial advances continued throughout the decade, with Pipistrel’s small Velis Electro becoming the first electric aircraft to be certified by governmental aviation safety boards in 2020. More recently, in 2022, Eviation’s fully electric aircraft Eviation Alice made its first flight in Washington State. Though it flew for only eight minutes, it marked the first time a fully electric passenger plane had taken off, proving the feasibility of these types of aircraft.

Additionally, during the 21st century, engineers have begun exploring the possibilities of hybrid aircraft, which use both fuel and electricity. Today, several experimental hybrid aircraft exist, like the e-Genius, a small electric aircraft designed by the University of Stuttgart in 2021 and modified to have hybrid propulsion.

Electric aircraft have a number of benefits that make them effective in the modern world of aviation. The primary benefit is environmental—fully electric aircraft have zero harmful greenhouse gas emissions. Electric planes are also more economical than conventional fossil-fuel-powered aircraft in regard to maintenance and power costs. Since they have fewer moving parts, such as combustion engines, electric planes possess fewer points of failure and thus require less maintenance, which reduces the upkeep costs that come with conventional aircraft. Furthermore, electricity can be more cost-effective compared to fuel; electric aircraft consume energy at a fraction of the cost of fossil fuel aircraft. For instance, a fully electric version of the e-Genius flew 62 miles using just $3 worth of energy, a mere fifth of the cost of the fuel required for a comparable gas-powered plane on the same flight path. Additionally, due to their use of electric motors over conventional engines, electric planes are far quieter than gas-powered ones, which reduces noise pollution and makes them optimal for densely populated regions.

However, the range and time limitations on battery technologies for electric vehicles are an obstacle. Lithium-ion batteries used in electric planes are up to 50 times less energy-dense than fuel, so electric aircraft can’t fly as long or as far as traditional aircraft. For instance, the Velis Electro has a range of just 125 miles, while the similarly sized but conventionally fueled Cessna 162 has a range of over 500 miles. Smaller and more energy-efficient batteries must be developed for large-scale applications in aircraft. Additionally, any new electric aircraft needs to have less mass than current models. Since batteries are less energy-dense than fuel, an electric aircraft will be forced to carry batteries heavier than the weight of a conventional aircraft’s fuel tanks to cover the same range. This means that weight will need to be removed from other areas of the aircraft.

To deal with these technological shortcomings, rapid development is occurring in both new aircraft technology startups and larger entities like NASA and Rolls-Royce. Currently, about 170 electric aircraft projects are underway or being conceptualized, which demonstrates an increasing interest in electric aircraft technologies. For instance, new battery systems that would increase energy density are in development. One unique lithium battery developed at MIT is both lightweight and twice as energy-dense as current lithium-ion batteries, making it ideal for powering an electric aircraft.

Though many necessary technologies remain in the infancy stage, for now, the future appears bright for electric aviation. Commercial airlines see it as a lucrative investment in the long run because it will allow them to reduce flight costs and paint themselves in an environmentally conscious light for public perception. Furthermore, the quieter nature of electric aircraft will improve passenger experience. 

While electric aircraft have significant potential to cut down or even eliminate the impact of the aviation industry on greenhouse gas emissions, it is important to remember that no large-scale aviation revolution can be made until the technological challenges currently limiting improvement are addressed—an endeavor that could take decades. A fully electric aviation industry requires a united effort from researchers, engineers, and leaders in the aviation industry to make it a reality, but rewards from electrifying the aviation industry such as creating a healthier planet for generations to come are well worth the struggle.