here's a pretty neat idea for dealing with intermittent energy generation:
http://www.highview-power.com/wordpress/?page_id=1320f
for those who can view it - http://www.bbc.co.uk/news/science-environment-19785689
and another vid of the (engine/plant) inventor: http://www.youtube.com/watch?v=NOImbv_xcT8
currently undergoing semi-production scale trials in Slough, UK.
always been a fan of low energy stuff - sort of turning the problem on its head so to speak. not necessarily the most efficient process, but not bad either and with further room for improvement.