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_...