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I think your factor of 4 is overly pessimistic. Again, remember that
the conversion losses will apply only to a portion of the energy, not
to all of it. Besides immediate use of electricity, there's also solar
space heating and water heating which don't even suffer from the
low efficiency of photovoltaics. Some energy can be stored in
pumped hydropower facilities, which are much more than 25% efficient.
Even when we need to use hydrogen for energy storage, it is
quite possible to convert that hydrogen to electricity at better
than 50% efficiency. Combined-cycle gas-fired plants already do
better than 50%, and fuel cells may do better still, as you say.
For transportation, we currently live with engines that are only
about 25% efficient. Replace those with 50%-efficient fuel cells
and you can probably live with the energy cost of producing the
hydrogen in the first place.
Currently, many utility customers pay higher rates for electricity
at times of peak demand, because it costs more to generate the
extra electricity at those times. In the western U.S., peak
electricity prices paid by utilities have been skyrocketing, as
I'm sure you've read in the news. In a future economy based
mostly on renewables, electricity prices will probably be much
higher at times when the sun isn't shining and/or the wind isn't
blowing. This will encourage customers to use less electricity
at those times, just as many large industries already use less
electricity when they have to pay peak rates. It isn't obvious
to me that the overall inconveniences will be any greater than
the ones we currently live with (especially when you factor in
the environmental costs of current energy sources).