I came across an interesting podcast interview by Aviation Weekly, in which two aerospace industry analysts discuss progress in building electric planes, and make predictions about the future of the niche. Here’s a list of their key points:
- There is a strong, long-term trend for aircraft to have more electronics, and fewer mechanical components like hydraulics. The Boeing 787 is the pinnacle of this.
- Even though gas-powered planes get more fuel-efficient each year, the total number of plane flights is growing so fast that, by 2050, 10% of global CO2 emissions will come from planes. As time passes, public pressure will grow to reduce aircraft emissions. Logically, this will help the electric plane industry since they are less polluting than gas-powered planes.
- A stumbling block will be the disparity between the stated and revealed preferences of customers: While most people claim to care about global warming and claim they’d be willing to pay extra money to avert it, they might not actually be willing to pay more to fly on a low-emission electric jet. [Consider how people today harshly complain about the small seats, bad food, and nickle-and-diming common on regional airlines, yet they aggressively demand low ticket prices and don’t want to pay more money for better service.] Electric planes will be more expensive than gas-powered planes for decades to come.
- As with cars, there are two basic types of electric aircraft: all-electric and hybrid-electric. Many new technologies from the auto sector are crossing over into the aircraft sector, so the electrification of cars today yields insight into the future of planes.
- A big difference is that plane engines require ~100x as much power output as car engines. Low battery weight is also much more crucial for planes, and is the primary impediment to their development. Electric planes will only become feasible once a battery with 500 watt-hours per kg is created [for comparison, a Tesla Model 3’s batteries are 207 Wh/kg]. Even that would be an order of magnitude less energy dense than jet fuel.
- While advances in battery technology are unpredictable and happen in fits and starts, long-term trends suggest that a 500 Wh/kg battery will be invented around 2030.
- Small planes that traverse short-distance routes will be electrified first. Large planes designed for long-distance routes won’t be electrified until the energy density of batteries equals that of jet fuel. The lag time will be decades long.
- The number of experimental electric aircraft is rapidly growing. Most of the prototypes and their corresponding startup companies will fail.
- $15-20 billion would be needed to develop a large, all-electric passenger plane. Due to the high cost, today’s electric plane startups are focusing on making small planes.
- Electric aircraft could demand very different architectures from gas-powered aircraft. For example, large electric aircraft wouldn’t have fuselage-wing layouts. [The pundit doesn’t elaborate, but the default alternative is the flying wing layout.]
- In 20-30 years, the aerospace industry could look very different.
- To meet the energy demands of electric planes recharging their batteries on the ground, airports would have to be massively upgraded with power infrastructure. [In addition, if the planes had different layouts like flying wings, the airport terminals themselves would need to be rebuilt to accommodate the planes.]
- China could seize the global lead in electric aircraft. The country has the technological expertise to make advanced electrical components and batteries, it lacks an established aerospace industry that would politically resist plane electrification in order to protect investments in legacy fleets of gas-powered aircraft, and its government supports any high-tech innovation that could lead to leadership in some industry.
- “Subregional,” inter-city plane flights might get much cheaper. Electric, short-takeoff-and-landing (STOL) aircraft could use airstrips close to city centers in the future. This would pose a big challenge to inter-city rail networks.
Finally, let me cite one of my personal predictions, from my big post:
[By the end of the 2070s] It will be technologically and financially feasible for commercial aircraft to produce zero net carbon emissions. The aircraft might use conventional engines powered by synthetic fossil fuels, or they might have electric engines and very energy-dense batteries or fuel cells.
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