Lennart Stridsberg pulls in a letter to the editor on the DN Review (19 February), an equally enthusiastic as ignorant lance elflyget. Since each kg of fuel must be replaced with about 30 kg of batteries is elflyg, except in some special applications, an aeronautical impossibility.
The global air travel is increasing by 4-5% per year. At the same time increases emissions of greenhouse gases.
today, there are approximately 30,000 passenger aircraft in the world, of which about half has about 150 flygplansstolar. In order to make the difference in terms of emissions of greenhouse gases would, say, ten per cent of capacity need to be replaced annually. A significant capital destruction and the large costs of whatever nature of the new technology.
viktskänsliga. The fuel is a big part of the take-off weight (10-35%), and the tare weight represent between 50 to 60 per cent. Therefore, always have a great deal of effort been expended to reduce the fuel consumption, which also means a big cost directly and indirectly (pushing up the weight of an aircraft and thus the price).
the Kerosene contains about 12.4 kWh/kg of fuel. With regard to the efficiency of a typical engine, this will be approximately 3.7 kWh/kg net.
As an example, weighs a 100 kWh battery for the latest generation of Tesla-elbilmodell about 600 kg = 1/6 kWh/kg battery. With regard to the efficiency of the electric motor and the fan/propeller, this gives around 0.12 kWh/kg net.
to the efficiencies of the various components must thus each kilogram of kerosene is replaced with about 30 kg of batteries.
the take-off weight of 150-the seats, the Airbus A320, respectively, Boeing The 737 is about 60 tonnes. For a ”typical” flight, 20 percent of the starting weight to be fuel (of which five percentage points in the reserves).
Traded to at the start of stored electrical energy, the batteries would (”fuel”) with ”Teslastandard” weigh 360 tons. Already the required reserves requires 90 tons of batteries. Not even the great improvements of the aerodynamics, or curb weight would make any principled difference.
battery-powered passenger aircraft regardless of size, is aviation technical impossible, even for very short distances. The batteries must be at least 20 times better for that battery-powered aircraft shall be able to become a reality.
the Electric drive would also not entail any particular technical advantages, but rather the contrary. This also applies to claims of ”quiet elflygplan”. In almost all applications noise, because of high spetshastigheter, the propeller/fan the most.
of Course there may be specialized applications outside the large scale commercial aviation, for example, in sport aviation, where the electric drive can be interesting.
