Sorry, I do not march to your drum.  Your attitude is demeaning and it is obviously unproductive to dialog with you.  Your questions are trivial.  Tidal energy is obvious.  Thermal energy conversion is extremely inefficient since thermodynamics tells us that at best conversion of heat to useable energy is limited by the temperature differential between the hot and cold reservoirs used in the system divided by the absolute temperature of the hot reservoir.  Additionally the small temperature differential available from vertical temperature stratification means that the operating pressures of the system are sub-optimal.  Moreover, the environmental effects of seriously disturbing the normal temperature stratification of the ocean is unknown and has the potential to seriously disturb ocean life.