Is a Hydrogen/Electric Car REALLY green?

Question

Hydrogen cars for the most part use a Fuel Cell to "burn" hydrogen producing Energy. This requires hydrogen to be separated from water, and requires the same amount of energy as you would get from the fuel cell. if the fuel cell & Electrolosys were 100% efficient. Neither are, and some estimates are as high as 75% energy loss due to inefficiencies.

The Byproduct of the fuel cell is water vapour which wikipedia states accounts for 36-70% of the greenhouse effect. I also can't help thinking about the environmental impacts if all the millions of cars on the roads today produced water vapour and the amount of rain this would produce, Mudslides and floods etc.

Electrolosys is the process that splits water into Hydrogen and Oxygen, however as the name suggests, this requires Electricity to work. "The Grid" or electrical supply for this electrolosys or my electric car is largely powered by fossil fuels. Just cause i cant see the pollution from an electrical outlet doesnt make it green

Answer 1

Hydrogen cars - at the moment no.  Electrolysis is far too inefficient of a process.  Even using renewable energy to break the atomic bonds in water to get hyrdogen wouldn't be green, because you'd be wasting that renewable energy on a highly inefficient process.

Much better would be to power an electric car on renewable energy, because electric motors are about 90% efficient.

Even on the current US power grid mix, electric cars are much greener than gas cars (and even hybrids) due to their high efficiency.  See the study linked below for further details.

Answer 2

Nothing that consumes resources is REALLY green.

but electric vehicles are nowhere near as bad environmentally and personally as infernal combustion. electric motors are far more efficent & have much better torque charactistics for motive use.

less noise pollution, less composite complex metalurgy or clunky transmission & oils, fully recycleable batteries, less particulates, no leaky & off-gassing tankers or pipelines; no refineries; refuel at home or work; electric generators run at optimum load & temperature, constantly monitored & maintained....

Answer 3

No.  It all comes down to NET ENERGY GAINS, which we have not yet been able to extract from hydrogen.  Gains are negative so far because it takes more energy to isolate hydrogen than what it can offer when burned.

Electric cars are more green if, as mentioned, the source of the electricity it is charged with is green, and, more than likely, it is not.  Even if the source is not green it will still be better than fossil fuel burners (with respect to emissions).  However, this brings me to the important reason why they are NOT green, which is that the extremely large batteries they require do not last forever and are very toxic to manufacture and are very hazardous to dispose of.

Toyota even admitted to this when manufacturing the large Prius batteries which are still much smaller than the batteries that go into electric cars.

Answer 4

Only if the hydrogen comes from electrolysis powered by renewable energy.

There is more exotic analysis you can do.  If you can separate the hydrogen from the hydrocarbon by reforming it, the efficiency of a fuel cell is much better than a combustion engine, so that's an improvement.  If you can separate the the hydrogen and sequester the carbon, that's even better.  Although in both these cases you still have to mine the fossil fuel resource.  

I've imagined giant floating solar platforms in the ocean to create the hydrogen. The energy you intercept to create the hydrogen wouldn't get to evaporate some rainwater, but when you drove your car the water vapor would come out your tailpipe in Des Moines.

The earth is one big system and if we are going to engineer it, we better be sure what we are doing.  Oops, we're already engineering it.

http://www.solarenergyltd.net/energy%20i...

Answer 5

I would power electrolysis through solar power, not fossil fuels. The only thing that gets into the air is the hydrogen itself. To create massive amounts of rain and etc., you need water vapor. Maybe hydrogen ICE is better with your theory??

Answer 6

Electric Yes

Hydrogen No,

And then only of the electricity is coming from a source that is "green"  Of those sources Wind, Geothermal, hydroelectric, and others are all better sources than Solar.

At the moment solar power is not a good way to produce mass amounts of electricity.  It works great to power a single home but the effiecency of the current panels we have is not good enough to justify the energy to space ratio they panels take up.

Answer 7

They're part of a system.

We also need electric power plants that don't use fossil fuels; nuclear, solar, wind.

Water vapor is responsible for most of the greenhouse effect.  But it can't cause global warming.  Excess water falls out very rapidly as precipitation.

Excess CO2 stays in the air for years, which is why it does cause global warming.  More here:

http://environment.newscientist.com/chan...

Electric/hydrogen cars are not perfect.  But they're far far better than fossil fuel driven cars.

Answer 8

Be very careful as the H atom is so small it will leak through anything. I have worked with Helium and on a satellite dish it was always leaking. Hydrogen is also very explosive. A few gallons of liquid hydrogen could blow away the hold block.