There is a very interesting technology that was described in the scientific press some 10 years ago about a system that runs water over a catalyst the liberates the H2 from the water at a sufficient rate to run a fuel cell which in turn produces water as well as electricity. The claims were that water losses were less than 1 litre per 1000kms. Where's the catch? the catalyst obviously expires over time and needs to be exchanged, but they envisaged this to be done at a service station as a "refueling" process. The used catalyst could then be recycled using solar energy. The real advantage of this is that 1. there is not a lot of hydrogen avaliable at any one time reducing explosion risks. 2. it becomes a "solar" cycle using entirely renewables. 3. Far less chance of fire in an accident.
The only downside I see is keeping the catalyst blocks dry in a "Sandy" or "Katrina" situation (although this can be done) and what happens when a car ends up in the drink?
I had a quick look and can't find that article, but I think it was New Scientist.
Excellent addition to the discussion (the A/C and battery replacement issues.) On the natural gas front I would like to advise that New Zealand actually has a very successful natural gas (CNG) program, with a lot of vehicles taking advantage of tax reductions, and in Australia they have a petroleum gas program (LPG) where 100% of taxis, a lot of regular drivers (about 500,000 vehicles or about 4% of the fleet) and there are no issues with driver refilling, it is safe. Check this Wikipedia link to see how globally successful these programs are http://en.wikipedia.org/wiki/Autogas
I agree that both the battery and AC issues are also drivers against financial payback on some applications. Battery replacement is certainly an issue; more so on full EVs, which run through a larger state of charge (SOC) range in operations. The charge sustaining HEV class highlighted in the article use a narrower SOC band (like the original Prius') and have less severe issues with battery life.
In addition to AC with PHEV and EV applications; there is also a winter driving issue that impacts economics. As the temperature has started dropping my Volt now runs the engine for several minutes on every drive to prevent operating the pack at low temperature. This also is less of an issue on basic HEVs where the engine is always operating.
Can you say why a "coast" mode would be better than active regen to bring the vehicle to stop? Maybe I misunderstood what you were driving at there. Zero pedal position can certainly be observed in a control system to indicate coast and an opportunity to recharge a pack.
Yes, I do have an idea. It is an insignificant amount. It has become fashionable to cite statistics claiming that refining uses large amounts of electricity. That is flatly wrong. The statistics that are cited indicate the energy equivalent of electricity that is used in refining. The energy used in refining is in the form of natural gas, not electricity.
The things that have been left out of the discussion are the impact of battery replacement on the economics of all electric vehicles, hybrid or not. And the distance killer for all EVs is air conditioning, which would cut the range by more than half in city driving. Nobody else mentions that unfortunate reality. The addition of a driver initiated "coast" mode to the start-stop vehicle can easily provide a large increase in MPG at a very small additional price. But it would depend on driver skill because a computer is not able to adequately perceive the driving situation, and that is not likely to change in the next decade.
Natural gas would be a good fuel, but the logistics of distribution would be a real problem, and the general public is no way ever competent to do natural gas fueling of a vehicle. That is the downside of all kinds of gas fuel options.
Strange argument, drink a glass of most hydrocarbons my guess is you won't see the next election let alone the end of oil. Sure we need carbon in our bodies and food, but history has taught us what atmospheric carbon at the 500ppm level looks like.
I hate to bring this up, but patriotism and price are poor metrics when you consider the long term implications of a carbon future. It really doesn't make a lot of sense to have a big pickup truck for a trip down to the local McDonalds or other short trips, so downsizing is not a bad thing. That said, diesels can achieve close to 50% efficiency and diesel hybrids better still and may be one of the over all better solutions as a I fear a lot of plug-ins will burn out the grid, We say they charge overnight, but 100e6 cars charging overnight with an average storage of 100kW is going to be a killer.
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