Once again, batteries just aren’t living up to hopes and dreams. Only a year ago Rolls Royce were excited about the nine-seater P-Volt electric plane — forecasting that it would be carrying customers on ninety mile hops in 2025 and 250 miles by 2030. Alas, it must have been a sobering year. The developers of the P-Volt have pulled the pin indefinitely and decided to wait until battery capacity and weight improvements make it realistic.
The P-Volt made by Tecnam
Pioneering electric plane shelved as batteries only last a few hundred flights
Howard Mustoe, The Telegraph
A pioneering electric plane developer has shelved development of its new craft after discovering that its batteries will only last a few hundred flights before they need to be replaced.
Tecnam said its main challenge was the energy density of the batteries available today, which are relatively too heavy for the amount of power they can store.
The speed at which the batteries would lose charge would erode the nine-passenger craft’s value, ruining its commercial prospects, it added.
“Not commercially viable” could be name for most Green engineering.
What do we call it when it’s so bad it’s not even subsidy-viable? — A blessing.
They’re talking about batteries “degrading in weeks”:
Tecnam was more forthright in their press release. “A few hundred flights” was the optimistic best case scenario. Fast charging and rapid turnarounds would make that worse:
The proliferation of aircraft with “new” batteries would lead to unrealistic mission profiles that would quickly degrade after a few weeks of operation, making the all-electric passenger aircraft a mere “Green Transition flagship” rather than a real player in the decarbonisation of aviation. Taking into account the most optimistic projections of slow charge cycles and the possible limitation of the maximum charge level per cycle, the real storage capacity would fall below 170Wh/kg, and only a few hundred flights would drive operators to replace the entire storage unit, with a dramatic increase in direct operating costs due to the reserves for battery replacement prices.
The power to waiting ratio was doomed
Waiting times are too long, the power is too low, and the battery life is terrible.
The truth is everyone in aviation wants fast-charging planes so the air crew and the capital assets aren’t sitting around for hours paying airport-world prices while they earn nothing. But batteries have a shorter lifespan if they are pumped hard, fast and charged completely full. Sadly slow charging and underchanging are not a solution either. Even if we treat these babies gently with long slow feeds, they would only store less than “170 watt-hours per kilogram”. As the Telegraph authors point out, jet fuel has an energy density of 12,000 watt-hours per kilogram, which is seventy times as much.
The bottom line, Tecnam explains, is that the only alternative to waiting for the development of much lighter, better batteries, is “extremely aggressive speculation on uncertain technology”. It would be a wild and risky bet. Not that we aren’t doing that with our energy grids.