OTEC is a boondoggle.  Don't waste money on it.   Look up the size and temperature gradient required to produce commercially viable amounts of electricity.  Wave energy might have commercial  potential,  but a working OTEC plant would end up being one of the largest,  most expensive facilities in the world.   Solar and wind are proven but aren't going to fly here either.    Geothermal doesn't work because people will file false lawsuits claiming they are exposed to gases (and need a multi billion dollar cable to get power to Oahu from big Island) ,  off shore wind doesn't work because the ocean is too unpredictable here, commercial solar is out because land is too expensive and environmentalists claim it kills birds,  and although nuclear power could solve power problem instantly, people are unreasonably afraid of it.   Only practical solution is residential roof top solar, but state officials are in pocket of HECO.  People have to commit to going off grid w/ solar and battery backup.