alt.energy.renewable

David Williams wrote:
> -> When there is an actual factory, producing actual cars _that run on
> -> air_, get back to us. I won't be holding my breath.
>
> There are vehicles in production that run on lead-acid accumulators.
> Compressing air to a couple of hundred atmospheres stores energy with
> a similar density (joules per cubic metre, or whatever). So it is
> plausible to me that a vehicle could be manufactured that runs on
> compressed air. It would be similar to a battery-powered car, though,
> small, slow, and with very limited range.

If they could get it to work, yes, it would be of very limited use.

> I'm intrigued by how they make the air-powered motor run efficiently
> while the pressure in the air tank decreases. How can it be as
> efficient when the pressure is 50 atmospheres as it is at 200
> atmospheres?

I would suppose that they either use a regulator to deliver lower
(say 50 atmospheres) pressure to the engine at all times or they
use a modulated valve that delivers variable amounts of tank pressure
air to the engine. No doubt both methods would work out to be very
similar mechanisms and the throttle needs to control the amount of
air going to the engine anyhow.

Anthony