Diesel generator emissions from data centers in Virginia
In the last three years, the pace of data center construction to support artificial intelligence has skyrocketed, bringing with it the threat of increased electricity costs, a rush to build gas-fired power plants, and the rapid growth of diesel backup generators used to keep data centers humming around the clock.
Northern Virginia hosts the largest concentration of data centers in the world, and each one sports dozens to hundreds of diesel generators. These massive generators are quietly permitted in neighborhoods with almost no public notice or comment.
Sierra Club’s new survey of air permits in Virginia reveals that diesel generators at data centers in Virginia have been permitted to emit nearly 13,000 tons of toxic oxides of nitrogen (NOx) and over 650 tons of particulates (PM) - comparable to the largest coal plants in the country. If these data centers hit their permitted limits, we estimate as many as 177 additional premature mortalities from new air pollution every year, concentrated in Northern Virginia and Maryland.
Amazon alone holds enough “minor source” air permits to allow its backup generators to emit 4,200 tons of NOx in Northern Virginia, about the same as a mid-sized coal plant right in the heart of the seventh largest metro area in the country.
The map below shows permitted emissions from Virginia data centers, clustered by town. Click on a circle or a top 10 data center owner filter to the town or owner. The background map shows estimated mortality by county using EPA’s COBRA model, assuming that every permit hit its annual limit.
The vast majority of the permits show that data centers are operating dozens of uncontrolled diesel generators for emergency backup generation. But these aren’t your standard backyard diesel generators. The average generator is 2,500 kilowatts, about the same as seven 18-wheeler semi-trucks - and each one could power a small town. The average data center hosts around 20 of these generators, but two dozen data center campuses host over 100 of them. In total, Virginia has already permitted around 10,500 generators.
The map below shows the capacity (in megawatts) of all of the diesel generators permitted for data centers in Virginia. Zoom in and click on a facility to see a satellite image of the facility or property.
