We've seen plenty of attempts to harness the movement of the sea for power, including underwater turbines
pumps, but those technologies are sadly unreliable. Denmark's Floating Power Plant has thought of that, however -- ingeniously outfitting its 350-ton Poseidon platform with wind turbines as well as the underwater variety, so it can harvest energy even when the sea is calm. As stability is a major concern, the company took design cues from oil rigs, so this bad boy should hopefully stay right-side-up even in the most perfect of storms. According to Inhabitat
, the company is pegging energy costs between 10 and 15 Euro cents per kilowatt hour -- competitive for the continent. This thing is currently stationed off the coast of Lolland in Denmark, although with any luck they'll be all over the world soon enough, at which point we will use them as bases from which to launch our futuristic, dystopian undersea armies.