THE KEY HURDLE in the hydrogen economy is this:
If we change to hydrogen - - besides it being VERY expensive relative to a plug-in hybrid ($ 2.50 electricity/100 miles - - before we have a true EXCESS of clean-made electricity (PROJECTED IN 2050), THIS WILL CAUSE A BOTTOM-LINE INCREASE IN CO2 and would therefore negate the non-polluting effect of hydrogen cars.
We keep seeing a strange, unexplained push towards hydrogen. Big business (auto industry, oil) apparently can't have it that people have cars for which they can make their own fuel (electricity from their own rooftop PV systems, $ 2.50/100 miles). Hydrogen as fuel is estimated (at the pump) to cost $ 6.00 and up for a gallon equivalent. Who would buy this overpriced and dangerous fuel, also knowing that it pollutes with CO2(?) - - unless there is no alternative ( auto makers literally refusing to produce plug-in hybrids)????
Are hydrogen cars the equivalent of today's computer printers? After buying one you keep getting milked by having to buy expensive printer cartridges (hydrogen gas)!