Microsoft Announces Biggest-Ever Wind Energy Buy by Barb Darrow @FortuneMagazine November 14, 2016, 8:15 AM EST E-mail Tweet Facebook Linkedin Share icons Microsoft on Monday said it has inked its biggest deals yet to acquire renewable wind energy to power its massive U.S. data centers. Its two new contracts represent 237 megawatts of generating capacity, bringing Microsoft’s wind power total in the United States to more than 500 megawatts, the company said. Megawatt (or 1000 kilwatts) is a standard measurement of electricity production. Microsoft msft signed with insurance organization Allianz Risk Transfer to acquire energy from a new 178-megawatt Bloom Wind project in Kansas. The deal “fixes” its contracted energy costs over a long-term agreement. Second, it inked a long-term contract with Black Hills Energy to buy 59 megawatts of energy “certificates” related to two wind projects near Microsoft’s Cheyenne, Wyoming, data center site. The combined output of those two sites should produce enough energy per year to supply its Cheyenne facility with all the energy it needs, Microsoft said. Get Data Sheet, Fortune’s technology newsletter. Cloud computing, despite its ethereal name, depends on lots of power-slurping data centers. That’s why companies like Facebook fb , Amazon amzn , Google goog , Salesforce.com crm , and Microsoft like to find—and publicize—clean or renewable energy sources. A few weeks ago, Amazon Web Services announced plans for a 189-megawatt wind power farm in Ohio slated to come online in December 2017. Microsoft and Black Hills Energy have worked out a new tariff that will enable the energy company to, as needs dictate, use the local data center’s backup generators, thereby eliminating the need for Black Hills Energy to construct a new power plant. “These agreements represent progress toward our goal of improving the energy mix at our data centers,” Microsoft president Brad Smith said in the company statement announcing the latest deals. Amazon to buy wind power from North Carolina facility Microsoft said it has already contracted with the 175-megawatt Pilot Hill wind project in Illinois and 110-megawatt Keechi wind project in Texas and signed a pact with the Commonwealth of Virginia and Dominion Energy to bring 20 megawatts of solar energy onto the grid in Virginia. For more on renewable energy, watch The two Wyoming projects are operational. The Bloom site is under construction and expected to come online in July, 2017, according to a Microsoft spokeswoman. Note: This story was updated to reflect when the power from these sites will be available.