Battery Airplanes? Nope! (MIT Technology Review)
By Robert Bradley Jr. -- October 20, 2022
“… the usable range of a 19-seat plane goes from about 160 miles to about 30 miles. For a larger aircraft like the 100-seat planes that Wright is building, it’s less than six miles.”
“Electric planes could take to the sky soon, maybe even before the end of the decade. But they probably won’t be able to take very many of us very far. For now … you might want to just ride a bike or take the train.”
In a sea of government subsidies and PR stunts, the Deep Decarbonization movement regularly tees up alternatives to direct fossil fuel usage. Posing as technological optimists, the strategy is to change the mindset of mineral energy dominance, so that an attitude of “if government builds it, they will come” can be politically possible.
But what is physically possible is not what is economically prudent, defined as using less resources rather than more to allow other wants to be met.
The market picks winners, leaving losers for government. Rather than tax-and-spend, taxes should be reduced for individuals and business to allow greater market entrepreneurship.
Perhaps sometime in the future a revolution will take hold from what is today’s best practices, but by then, the technology might be wholly different from what the government is subsidizing.
When it comes to airplanes, batteries are the killer: too heavy, too bulky. Energy density, in other words. (And that electricity is probably fossil-fuel created anyway.)
This story is told in This is What’s Keeping Electric Planes from Taking Off (MIT Technology Review (August 17, 2022). Casey Crownhart provides a reality check on electric airplanes. Excerpts follow:
- Startups are exploring how electric planes could clean up air travel, which accounts for about 3% of worldwide greenhouse-gas emissions. The problem is that today’s electric aircraft could safely carry you and about a dozen fellow passengers only around 30 miles, according to a recent analysis.
- The limiting factor is the battery, in particular the amount of energy that can be stored in a small space. If you’ve folded your legs into a cramped window seat or been charged extra for overweight luggage, you’re probably familiar with the intense space and weight constraints on planes.
- Today’s batteries don’t have the energy density necessary to power anything but the lightest planes. And even for those, the trip will be about as far as a long bike ride.
- Batteries have been packing more power into smaller spaces for about 30 years, and continuing improvements could help electric planes become a more feasible option for flying. But they’re not there yet, and ultimately, the future of electric planes may depend on the future of progress in battery technology….
- The battery requirements to fly even these short trips are pretty substantial. Heart’s 19-seat planes will carry about 3.5 tons of batteries on board, for a combined capacity comparable to that of eight to 10 electric vehicles….
- Some in the industry are skeptical that such planes could be successful without major improvements to batteries. “The battery technology is just not there yet,” Mukhopadhaya says.
- In a recent report by the ICCT, Mukhopadhaya and his colleagues found that the range of electric aircraft would be severely limited with existing energy storage technology. “We were surprised by how terrible the range was, frankly,” he says.
- Using estimates for current battery densities and plane weight restrictions, the analysts estimated that 19-seat battery-powered aircraft would have a maximum cruise range of about 260 km (160 miles), significantly less than the company’s claim of 250 miles.
- Forslund argues that estimates by outside observers don’t give a true picture of the company’s technology, since they’re not privy to details about its battery pack and plane design. (The company plans to design its own aircraft rather than retrofitting an existing model to run on batteries.)
- Reserve requirements could severely limit the true range of electric planes. A plane needs extra capacity to circle the airport for 30 minutes in case it can’t land right away, and it must also be able to reach an alternative airport 100 km (60 miles) away in an emergency.
- When you take all that into account, the usable range of a 19-seat plane goes from about 160 miles to about 30 miles. For a larger aircraft like the 100-seat planes that Wright is building, it’s less than six miles.
- “That reserve requirement is ultimately the killer,” says Andreas Schafer, director of the air transportation systems lab at University College London.
- According to the ICCT analysis, batteries would need to basically double in energy density to enable the short routes that startups are aiming for. That improvement likely approaches the limit of lithium-ion batteries, which are used today for EVs and consumer electronics. Even with this sort of progress, electric aircraft could only displace enough aircraft to cut less than 1% of emissions from the aviation industry by 2050.
- In order for electric planes to play a more significant role in decarbonizing air travel, energy density may need to quadruple, Schafer says. This could require novel types of batteries to reach commercialization….
- Electric planes could take to the sky soon, maybe even before the end of the decade. But they probably won’t be able to take very many of us very far. For now, unless there’s a fjord in the way, you might want to just ride a bike or take the train.
Yes, electricity for bikes, golf carts, or kiddie get-arounds. But not for airplanes, much less rockets. And cars and trucks–that is political correctness in place of economic correctness. At a time of record federal budget deficits, deep decarbonization subsidies and edicts are an easy cut.