"But if the origin of the energy is clean (hydroelectric, wind, solar), you can use that to break water down and then transfer that energy to the car."
Using electrolysis, right? How pure must the water be? One can't use seawater, as that would produce HCl instead of H2, right? Desalination consumes a lot of power, but it may be an option if enough hydroelectric / wind / solar power is generated.
I wonder if one could use the water stored in the ice caps for electrolysis. An enormous source of relatively pure water could perhaps be an economical and scalable source of H2. Just speculating.
It's not that bad; a little math suggests people would still use more water for flushing the toilet than transportation over the average day.
Energy density of 1 kilogram of hydrogen = ~1 US gallon of gas. A gallon of water has ~2/(2+16) * 3.8kg =0.4 kg.
So ~2.4 gallons of water + (ton of energy) ~= 1 gallon of gas.
PS: Bulk fresh water still tends to run at thousandths of a cent per gallon in most areas. But, 14 kilowatt hours desalinates 1000 gallons of seawater so 14 watts per gallon which is a tiny fraction of the energy needed to split water into hydrogen and oxygen.
> PS: Bulk fresh water still tends to run at thousandths of a cent per gallon in most areas.
The marginal price of water in San Jose is around 0.3 cents/gallon. However, the "connection charge" and various taxes and fees end up doubling the "as delivered" cost.
They are probably using desalinization. "Depending on local energy prices, 1,000 gallons of desalinated seawater can cost around $3 or $4." http://www.livescience.com/environment/070625_desalination_m... Even still adding ~1.5 cents per gallon of gas equivalent is not really expensive.
However, the connection charge is just highway robbery if you are really paying that per gallon. They might also be adding the sewer system charges based on your water usage.
PS: The average American uses ~90 gallon /day * 0.3 = 27cents per day * 365 = 100$ / year which is hardly breaking the bank.
For the water bill that I'm looking at, the connection charge (which is determined by the pipe diameter) is $15/month and taxes are about $3. This household is using about 40g/day/person and its monthly cost for the water is about $15.
> However, the connection charge is just highway robbery if you are really paying that per gallon.
San Jose city govt uses services to pay off various folk.
> They might also be adding the sewer system charges based on your water usage.
I just looked - the sewage charge is on the property tax bill.
The "water source" report that they send every year mentions ground and well water. It does not mention desalinization.
Using electrolysis, right? How pure must the water be? One can't use seawater, as that would produce HCl instead of H2, right? Desalination consumes a lot of power, but it may be an option if enough hydroelectric / wind / solar power is generated.
I wonder if one could use the water stored in the ice caps for electrolysis. An enormous source of relatively pure water could perhaps be an economical and scalable source of H2. Just speculating.