A lot of work has gone into wave power, but broadly it's not got anywhere - there's a lot of complexity in building machines which are robust enough to deal wit

A lot of work has gone into wave power, but broadly it's not got anywhere - there's a lot of complexity in building machines which are robust enough to deal with all sea states and the hostile marine environment, and the amount of energy which can be extracted hasn't made any of the trials so far particularly cost effective.