DEQ Proposes Changes to Backup Generator Rules

 The Virginia Department of Environmental Quality (DEQ) regulates backup generators primarily through air quality permits and rules governing their operation, particularly in the context of data centers. The regulations specify when generators can be used, their emission standards, and permit requirements, with a general emphasis on non-emergency use limitations. 

The data centers that increasingly fuel our interactions need to run 24 hours a day to keep the internet going. So, these facilities include backup power generators, often fueled by diesel or natural gas, and intended to run only during emergencies. Each data center is equipped with sometimes dozens, sometimes hundreds of tractor trailer-sized generators. Running generators burns fossil fuels for power emits pollutants such as particulate matter, nitrogen oxides, sulfur dioxides and carbon dioxide. 

In the summer of 2022 Virginia regulators proposed allowing Northern Virginia data centers to use backup generators in a more continuous manner for a five-month period during which energy “transmission problems” were anticipated. Homeowners’ associations that were already opposing data center projects in their backyards quickly coalesced to contest the proposal. The data center industry ended up asking regulators to rescind it.

But the outsized power demands have only grown since then, especially as more hyperscale data centers enabling AI come online. This past summer, the region faced another test of its grid when power demand for cooling reached record highs during heat waves in June and July. PJM Interconnection, which manages the grid for the northeastern U.S., issued permission in late June for places with high power consumption to use backup systems instead of the grid to prevent blackouts.

Electricity demand continues to grow faster than the generation being added to the grid. An extreme period of cold when the ubiquitous air heat exchanges cannot make the temperature gap and are forced to operate on the les efficient electric heat resistance to warm the homes could topple the grid.

The Virginia Department of Environmental Quality (DEQ) is currently accepting comments (until December 4th ) on a proposed change that would allow data centers to run backup diesel generators during planned outage events. Until now, these generators could only be used in the case of “sudden and reasonably unforeseeable events” or maintenance. In other words, these diesel generators–one of the most polluting forms of energy generation–were only ever meant to serve as backup power in emergency situations.

Below are the comments from the Piedmont Environmental Council:

“Utilities want the flexibility for the data centers to be able to run their existing backup diesel generators during planned outage events. This is driven by a desire to expedite timelines and avoid paying for more expensive options better equipped to protect public health."

"Planned outages, such as while transmission lines are built or worked on, are considered foreseeable, meaning data center operators have sufficient time — and are expected to — seek alternative options. Options typically used include: a) renting mobile Tier IV gas generators with higher pollution controls, or b) retrofitting Tier II generators with SCRs (selective catalytic reduction systems) to protect the public from pollution."

"But DEQ's proposal would allow data centers to potentially turn on hundreds to thousands of diesel generators, putting public health at greater risk. We believe this change should not be allowed or, at the very least, should be strictly limited and regulated."

The Public Comment Period ends on Thursday. Until then you can provide your comment at the following link: Guidance Document Public Comment Forum