Marine energy is the 'best of the best' amongst green energy sources: it has the greatest potential (in theory, the planet's oceans could supply the entire world with renewable energy), tidal and ocean current power plants are under water and therefore completely invisible, they produce electricity from 100 percent renewable energy sources (the water in the globe's oceans will always move around, well, at least until the sun swallows the moon), they are safe, and the icing on the cake is that they actually have positive environmental effects. Positive? Yes, studies have shown that marine life thrive in marine energy parks.