I heard Oxis energy are setting up a factory in Wales to produce batteries including for electric aircraft. They claim to have achieved 400 Wh/Kg which I think is 1.44 MJ/Kg.

And jet fuel comes in at about 43 MJ/kg. Assuming 30% efficiency of the engine, that is equivalent to about 13 MJ/kg of usable energy. For 1000 pounds of jet fuel (about 450 kg) we have a usable energy of 5850 MJ. A battery of similar energy content would weigh about 4000 kg. and would not lose weight as energy is used. So with similar fuel weights the range of the electric airplane would be about 11% of a turbine powered plane; gasoline energy density is very similar to jet fuel. This is just quick calcs and of course I am ignoring things like the lighter motor for the electric and the changes in fuel consumption for the turbine engine over the course of the flight.

I'm not slagging the effort but electrics have a long way to go......

The bigger the airplane the longer it will take to make use of stored electrical energy. For some drone, training aircraft doing pattern work or small aircraft local shuttle service it might work okay.
Maybe we should better try to beam the energy onboard up from the ground or down from space?

I hope that wasn't a serious suggestion.

Oh yes it was. Nothing for the narrow minded.
https://phys.org/news/2018-11-diamon...es-flight.html
https://www.newscientist.com/article...-indefinitely/

Me too, but it does point to a real issue. Electric motors are better than ICEs, but batteries aren't viable for aviation now, and quite possibly won't ever be. Is there another way of herding electrons which will be viable?

Nuclear power. Think radar satellites.
http://www.svengrahn.pp.se/trackind/RORSAT/RORSAT.html

I admit no realistic option for commercial traffic.

An electric motor has about 90% efficiency!

Quote all of the post! The electric motor itself might be 90% efficient but the battery has almost zero efficiency compared to fuel. That makes a fuel propulsion system way way better.

A small amount of power to a hovering drone.
How would you apply this to appassenger aircraft travelling at speed for hundreds /thousands of miles? Have you any idea how much energy that would require from the laser ?

I did not claim it would be enough to power an airliner.

I agree. The 30% number refers to the gas turbine or piston engine efficiency. In my rough calculation I generously give the electric motor 100% efficiency.

Baby steps. However, the sums don’t look as bad when you take into account:

It was replacing a Wasp Junior, which weighed 300kg and probably turned fuel into useful work somewhere in the 10-20% efficiency range (and less out of optimum power band) to make 450hp, with a 750hp electric unit weighing ~130kg at >90% efficiency. All the pipes, valves, generator, induction/exhaust, filters, controls, etc. can be removed which I’d guess is at least 50kg; you do need a power controller and wiring but because it’s fairly high voltage it’s not like huge bus-bars. That leaves space for ~200kg of battery before you get it to the dry weight it was before conversion.

For short hops there's no need to waste fuel to warm up the engine, there’s instant power available and maintenance should be less of a problem as the electric motor doesn’t care how many times it’s been started and stopped. Doesn’t need plugs and oil, either.

It’s obvious we won’t be getting transatlantic electric passenger aircraft for a while but this would seem an ideal place to start and see where the tech takes us. There are plenty of places where a quiet transport doing 10-20min legs would make a lot of sense...

Any idea what the voltage is? I haven't seen a number but assume it's not 12V! (or 6V like the old VW).

Personally, I'm a belt, suspenders/braces, and glue guy, myself. Hydrogen fuel cells, batteries, photovoltaics on the fuselage and wings (appropriately airfoiled) - all at once. One of the nice things about electric engines - they can run off more "fuel" sources than even a diesel. A watt is a watt is a watt.... ;)

Electric power is going to "work its way up" slowly but surely - from piston-prop-type aircraft to turboprop-type airframes. I won't even guess at when something resembling an "electric Embraer" will get here - if ever. But every little bit helps.

Unfortunately all technically feasible but a long way from commercial.
Electric aircraft, bio-fuels and laminar flow new design aircraft all part of the distraction developed by the ICAO regulator and industry to ensure that no one notices the industry has no plan to transition off hydrocarbon fuel.
Despite the often chanted 2-3% of CO2 emissions the industry repeats, by mid century it will be substantively more.

Unlike the maritime industry, aviation has no plan to replace the present source of fuel.

• Electric aircraft are an exciting concept, but as Fullwings notes a transatlantic flight a long way away......
• Bio fuels are technically feasible, but the sheer landmass required to grow the fuel would result in less food growing areas. Of course, bio-fuel still produces CO2... As a point of interest to replace 10% of the US airlines ASK would necessitate an areas the size of Florida to grow the fuel.
• Laminar flow developments aside, the flying wing concept as depicted by ICAO would fly for sure, but the re-design of all the associated infrastructure to support this new design is very very costly...

Your thinking is very much 20th century. Algae based biofuels have the potential to be carbon neutral, and it's estimated that - using algae - an area the size of Belgium could supply enough biofuel to supply the worldwide commercial airline fleet. The biggest drawback with algae is that, currently, the best algae for biofuel is fresh water, but there is optimism that the can develop a salt water version that works just as well.

BTW, what is the maritime industry plan for moving the current crop of 100,000 plus ton ships?

Japan, Korea and China are putting a lot of effort into installing a network of hydrogen filling stations, so that cars like the Toyota Mirai can run relatively pollution-free. As suggested above by pattern_is_full, an array of options feeding into the aircraft batteries could be the way to go. (Photovoltaic cells, even pax pedaling in the on-board foot rest gym bikes could provide useful trickles.)

LNG, electric and hybrid in operation, autonomous being built right now, wind assisted tested. Then we'll see.
Per