So water electrolysis has losses of 50-80%. And then you need to transport it to refueling stations (which could be pretty high). Edit: forgot the obvious, the losses in the actual fuel cell. 40-60%. Yeah that equation doesn't add up.

What losses to we have on the battery end? Transmission line losses (6%), li-ion charge/discharge losses (80-90%), losses due to the fact that the car needs to keep the battery warm/cool depending on outside temperature (pretty high in the winter, regular 120V outlet is not enough to keep the capacity up).

Personally I dismiss hydrogen mostly because I'm frightened by the thought of a bunch of high pressure fire bombs being driven around by drunk people.

One possible solution is renewable energy.

All current renewable energy sources have one big flaw. They produce energy when the circumstances are right, not when required. Beacause of this they cause issues in the energy grid.

If we could build water cracking facilities at the right scale with the right characteristics, that could help offset the efficiency/cost issues.

And on the issue of high pressure fire bombs, gas powered cars are pretty common here in Europe and those things are pretty safe. There are numerous safety features, not to mention that gas tanks are pretty tough vessels.

Edit: On the topic of fire bombs. I have today learned that one would not want Hydrogen tank in his vehicle.

>Edit: On the topic of fire bombs. I have today learned that one would not want Hydrogen tank in his vehicle.

Everyone comes to this conclusion when you realize how deadly compressed hydrogen is compared to liquid petroleum. Nothing like being burned by fire you can't see.

Given how quickly an explosive shock wave travels through hydrogen, I doubt anyone near the car would be alive long enough to even register a mild temperature increase when the tank blows up.

source? edit: that link doesn't really say that hydrogen is less efficent than batteries, just that it has less energy than the energy content of the original fuel, which is true with charging a battery too because of transmission losses, ect.

Nature? Free hydrogen doesn't really exist on earth; atmospheric hydrogen is something like 1 ppm. There's tons of hydrogen on earth, but it's all in water and hydrocarbons, which you have to split to get to the hydrogen itself.

The Wikipedia article on water splitting notes that "production of hydrogen from water requires large amounts of energy and is uncompetitive with production from coal or natural gas." If you're capturing it as a byproduct of an existing process, then it probably makes sense, but just applying electricity to water to generate hydrogen to burn isn't very economical right now.

And how much energy is lost charging batteries? Because there are no native sources for charged Tesla battery packs. You're either using electricity to charge them at your house (with 60% lost in transmission) or charging them closer to the power plant.

It's more efficient to simply use hydrogen.

I don't understand why anyone would be convinced by arguments like this that don't include numbers, when you can make the argument sound equally valid on either side of the debate.

> using electricity to charge them at your house (with 60% lost in transmission)

The overall losses in Germany are 7%. [1]

> It's more efficient to simply use hydrogen.

Only if you fake your numbers by an order of magnitude, see above.

> I don't understand why anyone would be convinced by arguments like this that don't include numbers.

Still better than your astroturf numbers. If hydrogen is better, so be it. However, the Tesla S can go 450km with one charge today and it can be charged everywhere.

An electric car is the nightmare of traditional car manufacturers: an electric motor costs nothing and lasts unlimited kilometers. You need no engine oil change, the brakes last a lot longer and cars will easily last 1.000.000 miles / kilometers and a lot more with little maintenance. You do need to change the battery but this is not money for the car manufacturer.

So there are two huge industries for which e-cars are a nightmare: petrol and classic car manufacturers.

Disclosure: I drive an MiEV an it works amazingly well.

[1] http://de.wikipedia.org/wiki/%C3%9Cbertragungsverlust (german)

I know, we'll get it from the atmosphere of Jupiter!

I know this is somewhat tongue-in-cheek, but what would the long-term consequences be of importing large quantities of hydrogen from off-planet and then binding it to local oxygen?

I suppose if we had the tech to do that, we might be able to find off-planet oxygen as well...? Except wasn't most of ours produced by plants splitting carbon-dioxide?

More water vapor, which is also a greenhouse gas. It's quite a bit more potent of one than CO2, in fact.

With a fleet of SpaceX Falcon Heavies?