A data center campus in southern Idaho is to run entirely on its own gas-fired power plant. TerraVolt Holdings, a small developer from Tustin, California, has signed option agreements to buy 1,077 acres in Cassia County outside the town of Declo, the company announced on 30 October. The plan is an initial 240 MW of on-site generation, islanded from the local grid.
An Option, Not Yet A Purchase
Some reports said TerraVolt had bought the land. The company's filing with the US Securities and Exchange Commission describes two options with the landowner, Wickel Land Company, priced at $30,000 per acre: about 903 acres for cash and about 174 acres paid with a convertible note secured on that parcel. Both have to be exercised together, and they run until 23 October 2027 with one six-month extension available.
The site is zoned for multiple use and lies on State Highway 81 near Interstate 84, close to long-haul fibre routes and to the Williams Northwest Pipeline. Gas is to come under a firm supply agreement of 55,000 MMBtu per day that TerraVolt announced earlier in the year. The filing does not say whether the plant will use gas engines or turbines; it lists both, along with switchgear and transformers, among the equipment whose lead times are a risk to the project.
Selling Powered Land
TerraVolt does not plan to operate the data centers itself. Once the site is entitled, it wants to sell shovel-ready building plots and supply power to them under long-term service agreements. Chief executive Joel Stone argues that staying off the grid avoids interconnection queues, shortens the time to power and keeps local ratepayers out of the cost. Every building on the campus will have to use low-water cooling such as closed-loop systems, a condition of each plot sale; the company expects water use to be mostly domestic and fire protection. BeBeez notes that the company started out as a geothermal developer and has since turned to natural gas.
Where A Plan Like This Gets Hard
Islanded power for a data center is a different job from backup power. With no grid to fall back on, the plant needs enough redundant units to cover maintenance and failures, it must follow the load of the IT halls on its own, and every machine runs many hours a year through every season of the site. The release sets a low-water rule for the buildings but says nothing yet about how the generating plant itself will be cooled. A developer at option stage has time to get those points into the specification. Our power generation page covers the cooling side of such plants; a similar off-grid approach is discussed in our report on Wärtsilä's study.
Sources: TerraVolt (press release, SEC filing), TerraVolt (Form 8-K), BeBeez
