Quote:
Originally Posted by photon
Good point about more efficient power plants (especially if you are trying to power your car with coal.  ). I was thinking of gasoline.
But if we go with the industrial coal power plant:
Coal -> Electricity -> Compressor -> Air -> Car
I don't think is going to be more efficient than
Coal -> Electricity -> Battery -> Car
Just because of the amount of heat that'll be generated when you compress the air in the first place.
Efficiency isn't the only factor to consider, energy density per unit weight and per unit volume is important too to get a usable range in a vehicle of usable size, and compressed air might be better in those.
I'm still on the side of developing battery technology.
Hm, not sure. I googled air compressors and ones capable of 300 bar seem to to use 4kw, assuming a 4 hour charging period that's less than a dollar. Even if you double the time to compress to 8 hours or add in losses due to heat or whatever, $2 to fill a tank seems reasonable.
At least now, if you converted most of the cars on the road to compressed air, I think the price of electricity would probably change lol. |
Here's something to consider about the overall efficiency model, if it were ever adopted wide-scale. One of the big problems with our power grid is that it's really crappy at storing power. Especially with hydro, solar and wind power, a significant portion of the potential energy that these systems create is simply lost because there's no way to store it.
One of the more creative (possibly crazy) ideas for storing power is to use large, underground reservoirs that have been emptied of natural gas as a sort of massive compressed air battery. Excess power on the grid during off-peak times is directed toward the compressors that build pressure during these times, that can then be released during peak times to generate power.
But let's say, rather than one massive underground reservoir, you had compressed air 'stations' scattered around a city. Each is basically a giant air compressor tank. During off-peak times, all of these tanks are filling up with compressed air using electricity that would otherwise be wasted. These become compressed air refueling stations for cars, and they'd also act a batteries that can return power to the electrical grid during peak times.