650 feet! That's as tall as 113 average-height American men stacked on top of each other. That's the size of a 54-story building. In other words, that's huge. But why?
Well, why build three, 2MW wind turbines when you can build a single, 7.5MW tower for a third of the upkeep? That's what the engineers at Germany's Enercon were going for when they built the massive E-126.
Constructed of tubular steel, the E-126 wind turbine stands 650' tall at the tip of the blade and generates enough juice to power about 5,000 German homes (or about 1,800 American ones. Crank up that A/C, brah.). Its rotors slice a massive a 413-foot-wide circle in the air, which is just 6' short of the world record. This lovely lady weighs in at a svelte 6,000 tons including her concrete base. The massive blades kick up very little turbulence thanks to the spoilers running along their lengths, nor do they make much noise thanks to their sound-minimizing tips.
It also has no gearbox, which is normally used to step up the generator drive-shaft's rpm's to account for wind conditions. Instead, the drive-shaft plugs directly into the generator (which sits in the turbine's nose cone) and uses two, slow-moving ball bearing rings to help regulate the speed. This minimizes the number of parts that will eventually need replacing. It also limits the blades to a maximum of about 12 rpm (or once every five seconds), which should be slow enough to spare all but the pokiest of birds.
E-126s were first installed in Emden, Germay in 2007 and only 24 are currently in service. Another 150 will come online when the 4GW Markbygden Wind Farm in Northern Sweden is completed in 2020.
[via Enercon E-126 Wiki - Wind Turbine Wiki - Enercon - MetaEfficient]