While large all-electric commercial aircraft are likely years away from becoming a reality, aircraft electrification is already underway. The National Renewable Energy Laboratory (NREL) reports that small-scale electric and hybrid aircraft are currently under development, with small e-aircraft already certified for flight.
Why Electric Aircraft is on the Rise
Several factors are influencing the growing interest in electric and hybrid aircraft. These include:
• Recent industry economic downturns are resulting in the retirement of inefficient aircraft with a greater focus on more efficient alternatives.
• Lower fuel costs of electric aircraft by up to 90% in some cases and a reduction in maintenance costs by up to 50% (NREL).
• Reduced noise on take-off and landing.
• Lower emissions and reduced carbon.
• The economic viability of serving regional, more rural markets.
• Increased accessibility by reducing ground transportation travel time, costs, and congestion.
• The potential for economic growth by expanding to underserved areas.
• Helping mitigate the existing pilot shortages and reduce the cost of pilot training via drones and unmanned aircraft
• The ability to provide critical community services including organ delivery and medical evacuation.
• Recent advances in power electronics, flight control systems, power generation, and other technologies.
Electric Aircraft Applications
According to NREL, electric aircraft applications span the full spectrum of current aircraft uses, including:
• Aerial survey and inspections for agriculture, disaster response, military logistics, and surveillance
• Flight training
• Delivery of high-value cargo such as critical medical shipments and overnight delivery
• Large-scale freight/cargo delivery
Meanwhile, passenger-related applications include
• Urban air mobility
• Military personnel movements
• Rural passenger access
• Remote community mobility
• Regional commuter service
• Corporate travel
• Large-scale commercial air service
“Ready Now” Components to Manage Noise, Vibration, and Motion Control
For decades, Parker LORD has supported the design of all types of fixed and rotary-wing aircraft in addressing the issues of noise, vibration, and motion control management. Our products have supported rotor hub components, powerplant mounts and avionics, and equipment mounting, to name just a few examples.
The problems associated with noise and vibration do not disappear with the use of an electric propulsion system; these issues need to be addressed to ensure these platforms deliver the same levels of safety and comfort provided by today’s conventional aircraft. Our electrification support strategy focuses on enabling the integration of the entire airframe and powerplant system, from mounting batteries, fuel cells, and power system components to attaching the aircraft propulsion and/or rotor systems.
As the market develops its requirements, it is clear that minimizing size and weight while delivering performance are key design drivers that our technologies are highly capable of meeting. Marc Papie, Global Manager of Commercial Aerospace, noted that “fixing aircraft noise and vibration issues is at the core of what we do. Working with our customers to address these issues early in the design cycle is the key to technical and commercial optimization.”
The Battery Challenge
A major challenge for electric aircraft in terms of long-distance flying is the low energy density of batteries (Markets and Markets). Key to the future of electric aviation is the development of advanced battery technologies, including greater energy density. Even those aircraft making relatively short trips will require batteries that are light yet powerful. The U.S. Department of Energy has set a 500 watt-hours per kilogram goal for aircraft batteries. Some estimate that, for large aircraft like the Boeing 737, this amount should be doubled.
Replacing a jet engine with an electric battery means the aircraft can fly more efficiently, extending the range and passenger capacity. Yet, with the benefits comes the risk of fire associated with the structural design of the battery. Preventing overheating in the battery is crucial and can be accomplished using a cell-bonding adhesive with thermal management properties.
Parker LORD’s CoolTherm® materials, the latest advancement in thermal management, combine the ability to achieve both the bonding and removal of heat. CoolTherm TC-2002 was incorporated into the design of Electroflight’s all-electric aircraft inaugural flight project “Spirit of Innovation” (designed and manufactured in partnership with Rolls-Royce and YASA) as it offered structural support while providing thermal conductivity to keep the battery cool and prevent it from overheating. Electroflight was thrilled with the results. “The benefits of the LORD CoolTherm thermal management portfolio in combination with the continued processing and technical support have been pivotal in the development and delivery of our battery solutions,” said Douglas Campbell, technical director, Electroflight.
In November 2021, the Spirit of Innovation became the world’s fastest all-electric aircraft, breaking two speed records.
As with the auto industry, innovation and technology continue to break barriers for electric aircraft. “The electric aircraft market will piggyback on the rapid advancements in battery technology currently propelling the auto market,” said Prasanna Srinivasan, Global Market Manager at Parker LORD. “As energy density increases, the business case of electrification becomes more appealing.”
The Future of Electric Aircraft
Markets and Markets™ have indicated the global market for electric aircraft is projected to reach nearly $3 billion by 2030. They point to the deployment of urban air mobility aircraft and the increasing use of electric aircraft for cargo applications and aerial mission-specific activities as the primary drivers of this growth.
In addition, electric aircraft manufacturers, in response to the growing concern for more sustainable air travel, recognize the need for cleaner aircraft as a major opportunity shortly. The battery, the most common onboard energy storage component of electric aircraft, will continue to be a driving factor in the growth of this industry.
Lastly, collaboration across industries, the academic community, and the government will be required if we hope to see electric aircraft take off. According to Esther Takeuchi, a battery scientist at SUNY Stony Brook, aviation, as we know it, was initially electric with the first round-trip flight by an aerial vehicle (La France in 1884) flew by the power of a zinc-chlorine battery. She believes in the future of battery-powered jets saying, “electric is ready for a comeback.”