One of my photos

Very alternative fuels

May 23rd, 2008 · Posted by Skuds in Technology · 4 Comments · Technology

The story about the financial benefits of petrol-electric hybrid cars in today’s G2 generated a lively discussion in the canteen today.  Maybe it was a mistake to involve engineers in such a debate…

We started by talking about how hybrid cars are inherently less efficient than pure electric cars – because a lot of the stored electricity is ultimately generated by burning petrol in the engine, while electricity generated by a power station involves a better use of fuel.

We touched on the idea of hydrogen cells, but soon somebody got onto the possibility of cars being run on compressed air.  This developed into how it would not matter if compressing air was inefficient in converting electricity into stored potential energy if it was powered by renewable sources like wind farms, and then it turned a little surreal.

It was declared that in theory, you could find yourself never totally stranded in a compressed-air car because you could  recharge the tank with a hand pump.  It might take a lot of muscle-power and time and pumps with gearing mechanisms so good as to be unlikely, but theoretically you could run out of fuel and pump in enough to get you to the next filling station.  Theory is a big thing to those with a scientific background.

From there it was only a small step to think that you could even pump air into your vehicle by hand while it was moving, by having the passengers pumping away like mad as you drive.  That all sounds a bit wacky races doesn’t it?

The reductio ad absurdum got even more absurdum when we imagined a situation where a lot of people sat in rows pumping away to force air into the tanks for a large compressed-air vehicle – like a steampunk version of the old triremes – which developed into double-decker buses where you could pay to travel upstairs or travel for free if you joined the lower deck where everyone was pulling at rows of levers while a fat bloke with a drum kept the rhythm for them…  so in half an hour we got a (almost) logical progression from dwindling oil supplies to a resurgence of a slave-based economy.

On the plus side, we have at least worked out how Boris is going to square the economic circle with his Routemaster 2 cunning plan.  As a fat bloke with a liking for percussion I should be OK.

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4 Comments so far ↓

  • skud's sister

    Electric cars will always depend on how you generate your electricity. Us smug buggers on a 100% renewable tariff might be okay but if your leccy company provides the result of burning endangered species over moon-rocks then you’d be better off walking. Or cycling, since the avaerage cyclist has the fitness levels of someone 10 years their junior.
    And the rows of people ‘pumping away’ just got me wondering whether it could be a use for the average contents of your local lovers lane..

  • Rob Glover

    I like the idea of the car powered by human muscle, but it does remind me a bit of the Flintstones. May as well get out and walk.
    I think the trade-off between hybrid and pure electric cars will come from the range you need to do in between charges and the relative charging time. It’s horses for courses – if you only use a car to go 3 miles to work and back, get an electric (or a horse). If you drive long distances regularly a hybrid is probably more the thing.

  • Skuds

    “Local lovers lane” What a cute and old-fashioned way to describe a dogging spot 😉

    Charging is always going to be what prevents pure electric cars from being attractive. During our conversation a colleague was excited about a car that could get a complete charge in about 20 minutes. That is very impressive – but still at least 15 minutes more than you want to spend at the ‘pump’.

    Talking of horses, one of my colleagues offered the supposed fact that companies have a legal obligation, through an old law that was never repealed, to provide a stable for any employee who travels by horse. Does anyone know if that is actually true, and if so has anyone tried it?

  • skud's sister

    If you regularly drive long distances then a hybrid mostly uses the petrol rather than the electric side (on motorwayish bits) so I’d stick with the diesel.