Greater range can be achieved by having the top surface of the wings and tailplane covered with solar cells. When an aircraft is flying at normal height - especially an airliner - any clouds would be below the aircraft thus the panals would get full exposure.

Mr R J Hammond, March, UK

If you bother to do any research, you will find that people do frequently "talk about the cost and carbon footprint of prodcing the electricity in these situations". And the result of investigations is that typically there is significant benefit to "producing the electricity".

Apropos of "the total environmental impact without toxic and expensive-to-replace batteries is probably better - rather like 'energy-saving' light bulbs, in fact..."
In fact, although it's certainly the case that CFLs present a problem that should not be dismissed -- and that LEDs will be a much better solution in the fullness of time -- given current power stations CFLs result in lower toxic emissions because the power stations themselves (largely coal-fired) emit, for example, mercury. So by reducing electricity consumption, you're net reducing toxic emissions.

mmalc, Cupertino, CA/USA

Electricity comes ofcourse from http://www.trecers.net/downloads/articles/trec_white_paper.pdf

A dirty source of electricity would spoil the fun, no?!

See also http://www.sciam.com/article.cfm?chanID=sa003&articleID=1FC8E87E-E7F2-99DF-3253ADDFDBEC8D41&ref=rss

Cheers,

Emil Möller

Emil Möller, Maastricht, Netherlands

Must have some length of cable.

Alan Kidd, Perth, Scotland

Congrats to those folks! There is certainly much to be learned about what will AND will not be feasable. I will be looking forward to more inovations of electric transportation.

I think the majority of selling point of rechargeable batteries is based upon the present excess capacity and lower cost (theoretically) available during off-peak hours.

the next couple years will be exciting as oil prices go through the roof!

Jay, New Mexico, USA

"So how exactly is this green? Where does the electricity come from?"

Nuclear.
Wind.
Geo-thermal.
Tidal.
Solar.
etc.

Chris, London,

"the fuel cost per hour of the Electra was €1 (70p) compared with about €60 for an equivalent petrol-driven machine."

But the petrol-driven machine won't be 'equivalent' because it will have more than 25hp to play with. If petrol-driven planes were made the same way as electric ones, they would be almost as cheap to run and a lot more convenient (you carry spare fuel in a can). Moreover, the total environmental impact without toxic and expensive-to-replace batteries is probably better - rather like 'energy-saving' light bulbs, in fact...

Francis Pickett, Arreton, Isle of Wight

To the extent that propeller-driven aircraft are in use today, this configuration is a good substitute, but I am still waiting for a hydrogen jet replacement for existing jets. The link below is for a fuel cell powered craft that I believe is still propellor driven, but has a jet configuration:

http://www.horizonfuelcell.com/

Jason M. Hendler, Melbourne, FL

You neglect to mention that propeller-driven aircraft are considerably slower than their jet engined counterparts, regardless of the means used to power them. So what possible use would they be in a commercial airliner?

Terry Chamings, Madrid,

So how exactly is this green? Where does the electricity come from? How great are the losses from conversion of fossil fuel to electricity, distribution losses, storage (loss in batteries).

Kidd Garrett, Bristol, UK

No one ever talks about the cost and carbon footprint of prodcing the electricity in these situations. Production of electricity is little based on renewable technology at present, some originates from nuclear power, most from fossil fuels.

I drive an old car, it does have a large engine and is not as fuel efficient as modern cars, but the carbon footprint on its manufacture was spent two decades ago, so am I eco ignorant or eco friendly? I cycle to work and only cover about 6k miles a year by car, whats right whats wrong?

Mike, Newport,