Electric aircraft

No Chris, the energy density of batteries is at least an order of 10 short, with the additional disadvantage that they do not get lighter as discharged! This is pie in the sky by idiots. Typical BBC.

Not very practical  with the sizes and shapes of aircraft we have become accustomed to, but there are already a few unmanned electric aircraft that are solar powered, the batteries charging up during the day and keeping it airborne during the night. The electronics onboard to keep it in the air and above the clouds so it can recharge are quite fun. works very well as a flying radio, for temp comms until there is a big storm, but more manoeuvrable and not as vulnerable as a balloon.

For passenger use, a battery that is charged on the ground will make more sense. You will not get anything like the speed and lift of a jet of course, but a slightly slower replacement for the short hop turbofan, with rather more wing area, is a more practical proposition, right now it is the small prop 2 and 4 seat aircraft that are being demonstrated that can fly for up to an hour or so.

The energy density is not sufficient for long flights.

I do however see a future for battery aircraft for "short hop" flights such as those connecting small islands.

I also expect to see unmanned electric aircraft, much larger than todays drones, for delivering mail and light freight to remote locations. Possibly human controlled, but with the pilot sitting in an office rather than being on board.

The range of electric aircraft could be improved by use of a long trailing lead for take off. High temperature 2.5mm flex could in the short term carry 60 amps at 1000 volts. 60 Kw from the mains during the energy intensive take off would preserve battery power.

I  agree, and so would a steam catapult, or for smaller craft, a towing cable launch like a glider, or even a  big zebedee spring. Many things are possible, not all are necessary or desirable. I suspect  lot of the hurdles will be regulatory rather than technical.

"This is pie in the sky by idiots.  " or perhaps pie not in the sky Dave lad.

Sorry couldn`t resist that quip.


Yep as has been said I think more development on short hops/drone type technology might go somewhere yet. however major flying principles I think will remain largely as is at present for a very long time yet. I think the points mentioned ref launching technology has alot of potential merit though.


Given enough time (which we don`t really have climate-wise) things will eventually change quite a bit and new tech makes exciting possibilities. 


Looking back to my teens there were things that to my parents and grandparents were nigh on impossible, pure fantasy. A lot is now fact. How I wish my paternal Grandad could watch me print a pic  taken by my Daughter in Oz a few seconds ago and hang it on the wall. It would seem as fantastic as interstellar time travel itself.


What we might achieve is exciting , whether we save or destroy ourselves is terrifying

Electric doesn't necessarily mean batteries.  The energy density of hydrogen is much greater than batteries.  The prototype hydrogen fueled cars that are already on the road are 'electric' in the sense that a hydrogen fuel cell is used to drive electric motors on the wheels - fuel cells being more efficient than internal combustion engines.  So a hydrogen fueled plane where the fuel cell drives electric fans is a possibility.

Hydrogen has a problem and that is that liquid Hydrogen has a fraction of the energy density of hydrocarbon fuels. So the takeoff weight would be several times as large, and the overall fuel efficiency lower! Is that some kind of advantage, because I don't think so! Also whilst electricity may be an intermediate, it would require even more windmills, which we all agree are not all that green and cannot be made without fossil fuels. I think that trying to make wood blades rather than epoxy carbon fibre (both from oil!) would teach most people the error of their ways. Steel would also become unavailable, and saying "just use scrap" and arc furnaces is a non-starter from several points of view. So just how big an entirely wooden windmill without Iron or steel can you make? Well planes found that about 200 HP was the maximum a wooden prop could stand and that at 2500 RPM. I wait to see the windmill!

A friend of mine is currently working on his PhD for electrically powered aircraft which is being sponsored by a major aviation player.


Clive