OT: More National Grid woes

[Andy Bennet]

EasyJet plans to fly electric passenger jets by 2027

[The Natural Philosopher]

Easy jet virtues signals 'its intention' to pretend to fly electric planes by 2027.

[Richard]

Strapping pigs to the wings as backup for when the batteries go flat?

[The Natural Philosopher]

[Graham Harrison]

What's the difference between the battery going flat and running out of jet fuel?

The rules for electric planes will be similar to those for today's jets - enough fuel to get there + holding time + diversion time+ various fudge factors (including pilots instinct!).

I'm as doubtful about the date as everyone else.

[Clive Arthur]

At least they could have regenerative braking.

Cheers

[Chris Hogg]

So where will the passenger sit?

[Vir Campestris]

Not enough to notice.

You'll be hard pressed to get any back before you land.

So you'll lose all the energy you used in the climb, all the energy used to accelerate up to cruising speed, and be able to reclaim the bit that got you to take off speed.

Andy

[The Natural Philosopher]

The former happens after one hour, the latter after ten...

Ah. so that will mean they will be restricted to landing immediately after takeoff then, at the same airport.,,.

Ive flown more electric aeroplanes than anyone in this group I dare say. I've done man many calculations on them. In the end all that is stoipping them is energy density and a bit of safety. Batteries ten times better would do the job.

Batteries, except lithium air, cannot be made ten times better. Not even in theory.

Lithium air is a big challenge on safety and on other grounds., They may never happen.

And they make a plane land heavier than it takes off :-)

[The Natural Philosopher]

actually windmilling props and fans on the glide instead of airbrakes would get enough back for a go around, maybe

[Brian Gaff]

Not new news is it? Airbus have been playing with the idea for years. I am not sure if its going to be feasible by then though. Brian

[Brian Gaff]

Well with the loss of this projected nuke what now? Brian

[harry]

Bollix.

[Jethro_uk]

It's by asking such wrong questions we're in the mess we're in generally.

The correct question is "what are the chances of a battery failing catastrophically compared to the chances of a conventionally fuelled plane failing catastrophically ?"

Loads of Samsung owners got burned arse cheeks from a non-flat battery.

Anyway, there's no way you'd get the power/weight ratio required for serious passenger flight without a step change in technology. Currently (but not exclusively) room temperature superconductors which would increase the efficiency of motors.

[Marland]

Jethro_uk

Transport in the future may need a step change in attitude if people decide they want to travel, If electric land transport reaches the goal that has been set out out for it that is going to leave a lot of oil that will now be available for things where battery stored energy still isn?t practical,it may be expensive either by becoming a rarer commodity or deliberate political intent but there will always be some wealthy enough to continue much as they do now. The ordinary person may find that flying off to a foreign city just for a weekends birthday pissup is no longer the cheap option that has been available since EasyJet and Ryanair proved that many were happy with the equivalent of a flying bus rather than a Railway dining car. If such people still want to travel cheaply to such destinations then maybe they could take a hit on the speed of the journey and the airship concept gets revisited where weight of batteries may not be such an issue and the energy they need to provide will mainly be for propulsion rather than keeping the craft in the air as well.

GH

[Jethro_uk]

I think in a few centuries, 1900-c.2000 will appear as oddities in that personal transport was so widespread.

[The Natural Philosopher]

Motor efficiency is already in the high 90;s for a decent sort of motors, There is a trade off with weight though - but you can have a motor that is light and efficient in crusie but's a bit rubbish on takeoff power

Batteries are an order of magnsitude too crap .

Only one technology is even remotrely capable of being an order of magnitide better - lithium air, featuring raw elemental lithoium and a massive fire hazard as well as being simply rubbish so far.

"The lithium-air battery (Li-air) is a metal?air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow.

Pairing lithium and ambient oxygen can theoretically lead to electrochemical cells with the highest possible specific energy. Indeed, the theoretical specific energy of a non-aqueous Li-air battery, in the charged state with Li2O2 product and excluding the oxygen mass, is ~40.1 MJ/kg. This is comparable to the theoretical specific energy of gasoline, ~46.8 MJ/kg. In practice, Li-air batteries with a specific energy of ~6.12 MJ/kg at the cell level have been demonstrated. This is about 5 times greater than that of a commercial lithium-ion battery, and is sufficient to run a 2,000 kg EV for ~500 km (310 miles) on one charge using 60 kg of batteries. However, the practical power and life-cycle of Li-air batteries need significant improvements before they can find a market niche. "

[The Natural Philosopher]

I think in a few centuries, 1900BC - 1900AD will appear as oddities in that personal (horse) transport was so widespread.

[tabbypurr]

The current world record is over 15,000 mpg. I reckon we could likely reach 1,000mpg in a road going vehicle if it tops out at 25mph.

NT

[Jethro_uk]

My view too. The Next Big Thing tech is really waiting for is improved batteries, so that a smartphone can go a few days without charge.

That and improved UI tech to allow the ageing to carry in using the iShiny X.

The latter will be driven by the need to ensure the wealthy pensioners carry on spending online ...