Rio Tinto has been forced to build special windmills in order to power their diamond mining operations in the cold Canadian Arctic, Bloomberg Businessweek reports. The mining giant spent $30 million to construct the four windmills, which are the first in the world to be able to operate even with winds that do down to minus forty degrees.

Ordinarily, the massive amounts of energy necessary to extract diamonds and other precious stones from the ground is tapped from a nearby power plant, carried by cables. Sometimes a special power plant is built specifically for the diamond mine, using a local water feature to create hydro-electric power. At other times, diesel fuel is trucked in and used to power an electric generator.

But those solutions are impractical diamond companies operating in Canada's Nunavut and Northwest Territories, where road closures on account of the weather shut down truck traffic for ten months out of the year, according to Bloomberg Businessweek.