Electrolyzing water is so inefficient in terms of Watt hours consumed that it is really only practical (unsubsidized) if your electricity is 2 cents/kWh or less, which is cheaper than even the very lowest cost hydroelectric used by huge data centers in the dalles, OR and Grant and Douglas counties in WA, which have the record lowest industrial kWh rates.

Not entirely true. I am not sure about the US but in Germany we have in times of very strong wind negative electricity prices. And that is to some degree the beauty of hydrogen: you can store it relatively well for some time, so you do not need to produce it right when you are charging your battery but when electricity is the cheapest.

It's not hydrogen is all better as some people here on HN seem to think the argument is, it's just that both battery powered vehicles and hydrogen powered vehicles both have some advantages over the other that might be very beneficial if used together.

I am from Germany too. Yes, sometimes we have negative prices for electricity. But that does not mean, it pays for investments for facilities, which only make sense with low or negative electricity prices. And it is a rather temporary phenomenon. With the transition from coal to gas, it becomes much more feasible to switch off power generation to avoid surplus electricity.

Long term, with enough battery powered electrical cars on smart grids, charging will be synchronized with the electrical power levels. And then we are back to electrolysis using 3x the electrical power.

This is absolutely right, it has been pointed out before that a hydrogen based energy world could give countries in the Middle East and North Africa a chance to still continue making money with energy after their oil is gone by producing and shipping solar hydrogen from the desert.

Energy cost from wind may go negative for very short periods of time, fluctuating, but if you include the capital cost of building huge wind turbines and connecting them to the grid, the average yearly cost of electricity from huge wind farms (unsubsidized) is not lower than 6.5 to 8.5 euro-cents per kWh. It's a lot better than hydrocarbons but it is NOT competitive for huge constant base loads with rare specific geographic hydropower bargains (2.5 US cents/kWh for "all you can eat") power if you can locate a facility very close to the Grand Coulee or Rocky Reach dams on the Columbia river.

> And that is to some degree the beauty of hydrogen: you can store it relatively well for some time

I thought storing hydrogen was challenging, since hydrogen atoms are so small?

Embrittlement is often cited by hydrogen naysayers, but if they're selling cars how serious a problem can it be? Maybe they just coat their tanks with something impervious?

I mentally substitute ammonia for hydrogen when the question comes up, because it is much less implicated in embrittlement and is otherwise quite similar to hydrogen. (IANA Chemist, but I've read that ammonia actually carries more hydrogen atoms than elemental hydrogen does, at the same pressure.)

Electrolysis can be made more efficient. [0][1][2]

For commercialization efforts see See also http://www.bloomenergy.com/ and http://ballard.com/.

Also - if the power source (like geothermal or solar) is remote, energy transport via high tension line can be inefficient. Hydrogen can be seen as cheaper transport of energy.

[0] - https://en.wikipedia.org/wiki/Polymer_electrolyte_membrane_e...

[1] - http://www.sciencedirect.com/science/article/pii/S0360544206...

[2] - https://en.wikipedia.org/wiki/Proton_exchange_membrane_fuel_...

Recharging your car at home at night only works for suburban US (and some parts of Europe), there are also lots of people like me who live on apartment flats 8 or 10 storeys high who cannot use that. There's also the issue with what happens to the battery, long-term, when you're driving your car at -15 Celsius in the winter and at +38 in the summer. I agree, though, for most of the HN demographic (own their own suburban homes, live in CA) owning a Tesla is feasible.

> there are also lots of people like me who live on apartment flats 8 or 10 storeys high who cannot use that

Why is installing a few NEMA outlets in the parking garage not an option? My HOA did just that, and while we still need to figure out the etiquette of taking turns (there are more vehicles than available outlets), it's not an architectural issue for most buildings.

End of the day, though, this is less about charging availability and more about range after a single full charge - you don't expect your apartment complex to host a gas station, for example, but you go out of your way to fill up at one and then drive on a full tank. Gasoline vehicle's top-of-the-line range looks to be 600 miles (Toyota Prius has a 12-gallon tank, so multiplying that by 50 MPG), top-of-the-line Tesla Model S is 90D with rated 292 miles of range, so I'd say things are getting pretty close to where one could drive to a Tesla SuperCharger, spend exciting 20-25 minutes there, and then drive charge-free for the next 4-5 days, with perhaps occasionally charge-up at the office, train station, or the mall.

A huge number of European apartment buildings have NO on site parking spaces whatsoever. Look at most of the apartments in Berlin for example. It's all street parking, or you have to rent a space in a parking garage somewhere.

Presumably not everybody is depending on street parking. For those who live in 8 or 10 story buildings, how many don't have a dedicated parking space if they have a car?

Apartment buildings will start to have chargers, if they have parking spaces.

Lots of Tesla owners live in northern climates, line or way and Sweden, and it works there too.