This is Poseidon 37, a floating power plant with the durability of an oil rig and the efficiency to generate up to 50 gigawatts of hydro and wind power a year. I'm assuming the trident is underwater in this shot.
The commercial plant prototype being built by Danish company Floating Power Plant measures 230 meters long and will weigh up to 30,000 tons—big enough, heavy enough, and low enough to the water to withstand the raging tempests that also, coincidentally, allow for the most energy production. They anticipate that the commercial version will house either three 1.5-2 megawatt turbines or one 5 megawatt turbine.
The Danish company expects the energy cost to be 11 cents/kilowatt hour, which is actually pretty good! Especially considering that it's 100% green. Now I just have to make sure no one beats me to a power plant from the Earth's mantle; I've had dibs on "Hades" naming rights since late 2004. [Green Tech Media via Inhabitat]