The hydrogen would be used to power fuel cells.

Alternatives would be battery storage or compressed air, or pumped water storage.

There was a recent post on TOD on compressed air storage, if you are interested.

The Oil Drum: Canada | Compressed Air Energy Storage - How viable is it?

One of the most critical aspects of the implementation of renewable electricity is the ability to store electricity.  If a good solution existed right now, our situation would be a good deal easier.  On the face of it, compressed air seems a likely candidate: relatively easy to make, store and use - so what is the problem?  Why isn't it used routinely?
More Thermodynamics than You Ever Wanted to Know?

We usually speak of storing and using energy without being very precise about what we mean.  That ends forever if you take a few chemistry or engineering courses.  Thermodynamics rules everything.

(Conclusion: compressed air isn't very good)

Likewise, with conversion to hydrogen the efficiency of the process is crucial.

Generation of hydrogen is one of the bottlenecks, another is storage.