Solar PV is probably $5.00 per watt installed, so something able to charge 8 kw-hrs/day would be about 1kW or about $5000. To displace about $1 of electricity per day. Call it $2 to account for the carbon improvement. Even so, that’s 2500 days to pay for itself.

As for the entropy in compressed air, etc., you aren’t really comparing apples with apples. Compressed air is a stored energy source (a ‘fuel’, if you will) and as such is considerably more convenient than the un-stored electricity powering the electric motor. Unless you have an extension cord, that too has to be stored somewhere, like a battery or whatever. The round-trip efficiency of charging/discharging a battery might be better than air compression, but the battery is more expensive than the compressed air tank. So the calculation is a bit more complex.

Overall, any energy storage from renewable sources, be it via batteries, compressed air, or even hydrogen, is ungodly expensive compared with present day gasoline prices. These costs are best mitigated by PHEV technology, which uses a small amount of stored renewable energy to do short drives, but uses the density of fossil fuels to provde the range needed by the consumer.

As for compressed air, the entropy losses on this are ridiculous. They are 15% efficient vs 90% for an electric motor. With your carport idea you are going photons-to-DC to-compressor-to-mechanical energy in a custom car that runs on air. c’mon.. And look at how shrimpy and slow these things are http://www.mdi.lu/english/

Compare this to the $0.08 (or less) a kWh you’d get charging your EV or PHEV car with grid electricity at night. Solar carport? , get real.. It is economically unrealistic misdirection like yours that is eating away at the progress we are making educating America through this important transition.

Perhaps PBP is supported by the gas station lobby, to find a reason to stop and buy that soda or bag of chips.

GM has long understood that visiting a service station is a hated experience for drivers, and one that drivers wish to avoid. PHEVs would reduce these visits. Battery change stations seek to extend it.

The plain truth is that without the battery change stations, BPB is really nothing at all; just a company seeking to socialize and control a fueling strategy with no net benefit to the consumer. PHEVs accomplish everything BPB seeks to do with lower cost, and less social control. Run them (the PHEVs) on E85 if you wish if you are concerned about gasoline usage.