I think the issue with hydrogen is being able to produce it without a carbon footprint and also to use less energy to make than it provides. I think with current technologies are a Zero sum proposition. I am hopeful this will change in the future.
Also it always amuses me talking to some people that have electric cars. They talk about how clean it is. Hate to pop your bubble but if you plug it into the grid to charge where do you think that energy is coming from as you charge your car??? Some of it might be from renewable solar or wind energy but some is from natural gas run generators, coal plants and other carbon footprint type generation.
Don't get me wrong, its the future and I am all good about it but it won't be the green non-carbon footprint transportation that we all want until you have a solar panel on the roof of your garage that charges your car after you get home, then you will have a green mode of transport other than the original carbon footprint left from the manufacture of the panels and car itself.
Just my opinion for whats its worth
On hydrogen: other issues include
1. well-to-wheel efficiency. Summary: horrible. It takes energy to product the clean water prior to electrolysis, takes energy to electrolyze, takes energy to compress/store (or liquefy, if that's your thing), and fuel cells are at best 60% efficient. If you're using H2 in a converted ICE, its probably 30% (a little better than gasoline, not sure how much). So you multiply those efficiencies together and its abysmal - 15% or so, depending on assumptions. Batteries are 90+% right off the bat; transmission lines about 95%, so you apply that to hydro and its 80%. Apply to a fossil-fuel plant, and well-to-wheel is about 80% of the powerplant's efficiency. Not bad and way better than gas or H2.
2. Transportation & storage - H2 is more prevalent to leak (its the smallest molecule, after all!), it embrittles metal under stress (ie, when the tanks/pipes are pressurized!), it embrittles O-rings. One cannot assume that NG pipelines & tanks can be easily converted w/o loss of H2 and higher maintenance costs.
3. Lifetime costs - current fuel-cells have cycle limits, just like batteries. Don't know the replacement costs but w/o lots of long-term testing, I don't think anyone does. Batteries have pretty extensive history of operations & testing, so their end-of-life performance and replacement costs are easier to factor.
4. Fuel cells - most current low-temp models (that would be appropriate for cars) use platinum as the catalyst. Pricey metal to begin with; now see what the price does if demand were to increase with more fuel cell cars (tho industry would likely come up with alternatives as they often do)
5. Water demand - H2 can come from methane or water. Methane is a no-go if you care about CO2, so you have to use water. Pure water. Lots of it. Which, if you've read the news, isn't always in abundant supply near cities or at all times of the year! There's always tension in some societies between growing food and growing material for fuel (ethanol). And there's tension between water users - farmers vs people who like green lawns. Now add in people who will want water to make fuel to drive their cars/trucks.
On the 'cleanliness' of batteries - your comment on GHG's due to charging at night is often cited but I think its wrong for the following reasons:
1. Most grids have nuclear & coal as baseload - while they operate, they operate at 100% 24/7. Varying loads are handled by hydro, then various types of NG plants as demand further decreases. Charging millions of cars at night doesn't increase coal power plant production (which as I said, if operating, is already at 100%), it would likely come from increased output of NG power plants, or more accurately, LESS decrease in power output of NG plants from their day-time peaks (because they otherwise cycle down at night and cycle up in the day) or maybe hydro.
2. Power plants operate most efficiently at 100%. So even tho the total demand on NG would be higher if everyone's charging at night, GHG/KwH is less as the plant operates at a higher output.
3. GHG emissions from NG plants is far less than ICE cars. From efficiency alone, a NG plant is about 3x's as efficient (close to 60% for more advanced plants compared to 20% at best for a car).
4. So, quick & dirty math - electric cars, per mile/kwh/etc, are doing to result in at most 1/3 emissions compared to ICE car (or less depending on the power source for charging, tho that's hard to reliably predict).
