As part of EPRI’s DCFlex initiative, a field demonstration was conducted to evaluate hydrotreated vegetable oil (HVO) as an alternative fuel for backup diesel generators used in data centers. The project compared HVO and conventional fossil diesel under real-world operating conditions at a data center facility in Dallas, Texas, using a 2 MW backup generator. The study was designed to address the limited availability of field-validated emissions data for HVO and to provide information that may support sustainability reporting, permitting discussions, and future evaluations of backup generation resources. Emissions testing was performed using U.S. Environmental Protection Agency reference methods, while a lifecycle greenhouse gas assessment was conducted using a GREET-based methodology. 

This report presents results from a field emissions test of HVO versus fossil diesel conducted on May 6, 2026, on a 2 MW Cummins QSK60 Series backup diesel engine (model DQKAB) at a Compass Datacenters facility in Texas. Testing was performed by Mostardi Platt using United States Environmental Protection Agency reference methods at two load conditions, 50% and 100% of rated capacity, for each fuel. Measured parameters included particulate matter (PM), gaseous emissions (NOx, CO, and CO2), total hydrocarbons (THC), non-methane non-ethane hydrocarbons (NMNEHC), and hazardous air pollutants (HAPs) including formaldehyde, acetaldehyde, acrolein, and methanol. Fuel quality analysis and engine performance data were also collected. A separate GHG lifecycle assessment (LCA) was conducted using the Argonne National Laboratory Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET) model.

This white paper provides insights into four DCFlex demonstration projects focused on flexibility in design, utility programs, grid planning, and energy supply. It highlights real-world demonstrations in Phoenix, AZ; Lenoir, NC; Paris, France and Chicago, IL showcasing techniques such as AI workload modulation, demand response, and backup power integration. These projects help to validate the technical feasibility of dynamic load management, fault ride-through capabilities, and carbon-aware operations, offering a blueprint for sustainable data center growth while supporting grid stability and accelerating renewable integration.