Data Centers Spring Up in Santa's Backyard

The star of Sweden’s hydroelectric system is a 56-foot-wide turbine named Gerhard, buried about a football field’s length beneath the Lule River. With the push of a button on a far-off computer, water tumbles down a 345-foot man-made dam and through Gerhard, making the turbine spin 107 times a minute and generating as much juice as a small nuclear reactor. Anyone nearby feels his organs vibrate and the earth shake.

Fifteen stations with similar turbines dot the Lule, which runs 280 miles from the top of the world down to the Gulf of Bothnia, between Sweden and Finland. The dams provide northern Sweden with a surplus of clean, cheap, stable electricity, and they have attracted U.S. consumer Web companies looking to plant their heat-spewing, power-hungry data centers in frigid Scandinavia.