Electric aircraft have consumed headlines as of late, as fuel and maintenance costs take their toll and the environmental regrets hit home. Based on the current state of technology, what is the appropriate market entry point? How should electric aircraft be introduced to the commercial market, in a setting that emphasizes their economic and environmental benefits?
Rolls Royce has it right: https://www.aviationtoday.com/2020/03/10/regional-aviation-likely-commercial-test-bed-for-hybrid-and-all-electric-aircraft/
Regional aviation presents the best opportunity for current hybrid and electric aircraft. With current battery energy densities hovering around 200-300wh/kg, ranges are limited far short of fossil fuel powered equivalents. As an example, a 737 assuming a similar mass fraction as a full fuel load will only achieve a full electric range of ~600 miles (a little over half of the flights in the US fall under this distance), compared to over 3000nm fueled by Jet-A.
This value proposition sounds depressing until the realization that the cost to charge is only $250 for a full charge at wholesale rates, compared to $3000 worth of Jet-A burned for a similar range flight. Additionally, overhead maintenance costs are significantly reduced: an electric motor has only one moving component, one which will not fail catastrophically and harm other systems. Electric motor overhaul intervals fall on the order of tens of thousands of hours, compared to 3,000-5,000 for jet engines. This interval for jet aircraft is further reduced by increasing cycles, as experienced by regional aircraft.
This is why regional flights make sense - lower operating costs, higher cycles on motors, bearable weight on existing airframes, and reasonable charging times. Until energy densities increase by an order of magnitude, long haul remains out of reach as a pure electric route.
How does this pertain to flight test? Flight test should, at the later stages, prove out end to end operations in operationally representative environments. This means flying out of region airports, charging on existing grids, and exercising the full logistical infrastructure required to turn the aircraft. Without developing and testing the electric ecosystem, commercial electric aircraft will never realize their value.
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