LOL to the Super Giant Capacitor thing, problem is dude that lightening will just blow that shiz nit up, its just way to powerful and you cannot keep the charge very well. Plus a 25 gigawatt battery has to cost SOOOOOO much.
About water and paddles....theyve kinda already done it...now now...dont say DAMN it...say DAM it. Rivers provide CFM much more steadily. Problems with ocean are basically same mentioned above, and that the Cost to energy gained ratio is just horrible.
Best thing is Nuclear Energy, it provides Sooooo much and sooooo cheaply and is virtually 110$ safe. Those idiots who riot are exactly that. You let Naval Carriers and Submarines which are MENT to be sunk, blown up and completely exposed which have Nuclear Reactors go away unscathed and nive big Land one's that arent ment to get attacked a hard time. Gimme a break, if your willing to risk the pollution of the entire ocean which produces like 75% of the oxygen we breath...exactly. Same bs with this global warming...One forest fire caused by lightening puts up as much carbon dioxide and other chemicals in the tree's and shrubs in the air as much as the whole united states in one calander year. Now, factor in that we prevent and stop forest fires and that the Earth has been warming up for a longgg ass time, who melted the ice in the ice age? Earth always does warmin and coolin, to think that we cause it is almost arrogant.(I do however believe that nuclear winters are possible by man's hand)