A report prepared by EmPower Analytics Group for the Natural Resources Defense Council estimates that air pollution from the proposed Stratos data center in Box Elder County, Utah, could cause substantial health harms and economic costs if the facility reaches its potential full capacity and is powered by methane gas. The analysis models different generator technologies and their projected emissions.
At a potential 9-gigawatt build-out, the report estimates that pollution could contribute to approximately 5 to 45 premature deaths and $75 million to $690 million in health-related economic damages each year. It also identifies possible increases in asthma cases, nonfatal heart attacks and hospital visits, as well as lost work and school days.
The estimates cover two types of methane-powered generation: combined-cycle combustion turbines and gas-fired reciprocating internal combustion engines, or RICE. The report says fine particulate pollution, known as PM2.5, is a key concern. Over 30 years, it estimates that the RICE scenario could be associated with 856 to 1,350 premature deaths and $13.5 billion to $20.7 billion in health-related damages. For combined-cycle gas, the corresponding estimates are 145 to 253 deaths and $2.3 billion to $3.8 billion.
The report says RICE generators produce more emissions than combined-cycle gas at the same capacity, making the choice of technology a major factor in the projected health impact. Its RICE scenario is modeled on a methane-powered data center in Millard County, Utah, for which 69 generators were permitted in early 2026.
The analysis does not include emissions from diesel backup generators in its combined-cycle scenario because Stratos’s plans for backup power are unknown. It does include diesel backup emissions in the RICE scenario, using the Millard County permit as a reference. The report notes that diesel generators can emit substantially more smog-forming nitrogen oxides, non-methane hydrocarbons and carbon monoxide than similarly sized gas generators.
Pollution concentrations are projected to be highest near the facility, in northern Utah and southern Idaho. However, the report estimates that more than 80% of the health impacts and related economic damages would occur outside Utah, affecting downwind populations in states including Colorado, Wyoming and Illinois.
The project, proposed by Canadian businessman Kevin O’Leary and his businesses, was approved by the Box Elder County Commission in May, according to the report. While Utah Governor Spencer Cox has said the first phase would use natural gas and later phases should turn to other energy sources, the latest developer filing cited in the report describes a 7.5-gigawatt data center using methane-burning RICE generators. The report says the filing does not commit developers to changing those plans.
NRDC commissioned the analysis to assess the potential health effects and economic costs of pollution from the proposed project and other data centers powered by fossil fuels. The report’s estimates are based on modeled scenarios, rather than measured emissions from an operating Stratos facility. (En dash?)
Sources: CleanTechnica.