The world's most potent underwater turbine uses ocean tides to create energy enough to power 15,000 homes each year. It works by turning blades with the movement of tides, producing over 2 megawatts...

Turning waste into power would be converting waste into electricity and more, there are different methods of turning waste into power/heat like incineration, pyrolysis, gasification, steaming,  and anaerobic digestion. This energy from garbage then can be used to power homes, businesses, and even vehicles.