Google's planned data center in Cheyenne, Wyoming, will get its electricity from a 2.7 GW package put together by the local utility owner Black Hills Corp. The company announced on 6 October that it had signed two definitive agreements with Google, effective 30 September and running to 2048. Black Hills will build 564 MW of new natural gas generation of its own at the existing Cheyenne Prairie Generating Station, at a cost it puts at $1.8 billion over 2027 to 2029.
The 2.7 GW figure includes reserve margins. Black Hills says it combines up to 590 MW of utility service with about 2.1 GW of Wyoming-based resources contracted from third parties, which Black Hills will manage through a privately managed microgrid under its Large Power Contract Service tariff. Service is to begin in late 2027 and the load is to ramp to its peak by 2030.
Google Pays For The Plant
Much of the release deals with who carries the cost. Black Hills says the contracts pass the costs through to Google, protect its other retail customers, and guarantee full recovery of the capital over the contract term, with early-termination terms and collateral requirements on Google's side. Google has already advanced $399 million for equipment, refundable, with a reimbursement deadline of 30 June 2027. Black Hills expects the project to contribute about $150 million of net income in 2030.
The point of the structure is that the large load pays for the generation built for it, instead of the cost landing on other customers' bills. We would expect to see it in more contracts of this kind.
Still On Paper
Several permits are in hand. The certificate for the Robinson substation was granted in May and the air quality permit for the Cheyenne Prairie expansion in August. The industrial siting permit, a transmission cost mechanism for large customers and two transmission expansion certificates are still pending, the last of them to be filed in the fourth quarter. Microgrid Media rightly notes that this is a contracted power structure, not an operating plant.
Black Hills has not said whether the new gas capacity will be turbines or reciprocating engines, and it has not named the third parties behind the 2.1 GW. Those choices decide most of what the site will look like: how many units, how fast they start, how the plant behaves on a hot afternoon at Cheyenne's altitude, where thinner air takes something off the output of any combustion machine and off the cooling air that carries the heat away.
For anyone following power plants built around a single data center customer, the details worth watching in the coming filings are the unit type, the number of units and the redundancy the microgrid is designed for.
