Berkeley Engineers Have Some Bad News About Air Cars 278
cheeks5965 writes "We've argued before over compressed air vehicles, a.k.a. air cars. Air cars are an enchanting idea, providing mobility with zero fuel consumption or environmental impacts. The NYTimes' Green Inc. blog reports that the reality is less rosy. New research from UC Berkeley and ICF International puts a period at the end of the discussion, showing that compressed air is a very poor fuel, storing less than 1% of the energy in gasoline; air cars won't get you far, with a range of just 29 miles in typical city driving; and despite appearing green the vehicles are worse for the environment, with twice the carbon footprint as gasoline vehicles, from producing the electricity used to compress the air. Given these barriers, manufacturer claims should definitely be taken with a grain of salt."
You should use two measures of electric vehicles (Score:5, Interesting)
The significant fact about electric (or hydrogen fuel cell), or electrically compressed air vehicles
is that electricity (and hence hydrogen via electrolysis, or compressed air tanks) can be generated
in all manner of relatively or completely "green" ways, whereas fossil-fuel transportation is
at least presently restricted to getting its fuel by digging up stored carbon from the Earth at
unsustainable rates.
So electric vehicles (or hydrogen fuel cell, or even relatively inefficient compressed air) vehicles,
are stepping stones on the path to a non-GHG producing future energy system.
So the "green-ness" or carbon footprint of these electrically based technologies should be
measured with two separate baselines:
1. What would their carbon footprint be if all electricity was generated with carbon-neutral generation
methods such as wind/solar/geothermal/hydro/wave/nuclear.
2. What is the carbon footprint assuming the US continues to maintain arguably the most carbon-dirty
electrical generating mix in the world.
Measured in this light, it can be seen that the complete issue is changing the electrical power source for the
US, in parallel with adopting one or multiple forms of transportation technology that is electrically based.
Either change without the other does not work. Both are necessary for effective improvement in emissions
reduction of transportation.
Cold Steam Engine? (Score:3, Interesting)
It occurs to me that a compressed air vehicle could be compared to a "cold" steam engine.
Have there been any scientific advances that could make steam engines in general viable for car sized engines?
Comment removed (Score:4, Interesting)
Re:Zero Emissions are worse?? (Score:3, Interesting)
Citation? I did a little googling, and it doesn't appear to be a hot topic by any standard. The biggest problems with nickel seem to be in its production, not its disposal, and I didn't see any references to nickel toxicity itself.
Plus, we're talking about battery disposal here. The odds are much better that they'd be dumped in landfills than that they'd be dumped in rivers, lakes, and oceans. With landfills, you'd be more worried about aquifer pollution, and I didn't see much concern there, either.
Re:At least they don't pollute the city directly (Score:3, Interesting)
These were also the same environments that fireless steam locomotives were used in. The hot water stores a lot more energy for a given volume than compressed air.
Re:"zero fuel"? (Score:3, Interesting)
Time to fish out the calculator (Score:3, Interesting)
Compressing air can be done with any source of mechanical energy. Put a windmill on your roof, gear it down, and have it drive the compressor directly
Translate this into practical terms.
Give me an estimate of the air car's speed, range, weight of cargo, weight of passengers.
Tell me how long it will take to refill the tank.
Re:Zero Emissions are worse?? (Score:4, Interesting)
i'm curious as to how much thought you're really given to this, above and beyond the 'mythbusters' level. firstly, you're right, Priora are not built with lithium batteries, though you should wish that they were. Lithium is NOT stripmined, Lithium salts are extracted from the water of mineral springs, brine pools and brine deposits. The metal is produced electrolytically from a mixture of fused lithium and potassium chloride. Nickel on the other hand IS strip-mined and while their disposal may not be all that bad, the production of nickel batteries is extremely harmful to the environment. IIRC there is a mine in Canada used for the production of Prius batteries, if thats the one i'm thinking it is, there is a 60 mile dead zone around it which contains about as much life as the surface of the moon.
there are of course problems with most forms of energy storage, the trick is finding ways to manage those problems.
Re:Full of Shit (Score:3, Interesting)
Get a deal for 100 megawatts at 50KV, line saturated to 70% of its capacity 24/7 except holidays,
Get a deal for 10 kilowatts at 110V saturated to 40% of its capacity in the evenings and 10% the rest of the time.
See how much you pay for KWh in the first case, how much in the second case.
Bulk trade rules apply to electricity much more than to normal goods.
Also, check how much a solar panel costs. About $1000/100W.
Considering about 15 cents/KWh energy, that's 1.5 cent/hour you save. That's 7.5 years for return of the investment, assuming no efficiency drop-off and all the infrastructure (inverter etc) for free. Now consider some 4 cents/KWh of energy a massive bulk customer like the solar panel factory pays, how long till that kind of investment is returned? 30 years? How well will the panels perform then?
Solar panels are a means of packaging bulk industrial energy into packges suitable for retail and reselling it to retail customers.
Re:At least they don't pollute the city directly (Score:2, Interesting)