HVO: The Case for Rethinking Data Center Generator Fuel

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HVO: The Case for Rethinking Data Center Generator Fuel Prime Data Centers’ Steve Benson explores how HVO fuel can cut costs, reduce emissions, and rethink sustainability in operations. Sustainability in data center operations is frequently framed as a capital investment issue, such as new cooling infrastructure, low-carbon materials, and next-generation power systems. These are important long-term priorities. But by focusing on large-scale transformation, the industry tends to overlook another category of opportunity: operational decisions that are fully within our control, require no significant capital, and deliver measurable results today. Approximately three years ago, I was asked to identify what changes could meaningfully reduce Prime Data Centers’ environmental footprint within those guidelines. That process led me to hydrotreated vegetable oil (HVO) as a replacement for conventional diesel in our backup generator fleet. The Operational Case Came First HVO is shelf-stable. Unlike conventional diesel, it neither separates nor accumulates water and does not require annual polishing. That single characteristic significantly reduces a recurring maintenance burden that most operators accept as fixed simply because they’ve never been offered an alternative. The cost math is straightforward. Across a multi-site fleet, annual fuel polishing quickly runs into six figures. HVO significantly reduces that cost. It also burns cleaner, producing less soot and leaving injectors and combustion chambers in better condition over time. In a mission-critical environment where generators sit mostly idle but must perform flawlessly on demand, fuel quality and combustion cleanliness matter more than operators typically account for. The operational and financial case must stand on its own. “This is good for the environment” will not carry much weight in budget conversations at most critical infrastructure organizations. “This significantly reduces annual five-figure maintenance costs, reduces vendor touch points, and improves engine cleanliness.” The sustainability benefits are real and important, but they tend to close the deal rather than open it. An Irish Rail train powered by HVO, showcasing how industries beyond data centers are exploring cleaner fuel alternatives. (Image: Alamy) What the Environmental Numbers Actually Mean The emissions data on HVO is well-documented. According to California Air Resources Board pathway data and the US Energy Information Administration’s analysis of California’s Low Carbon Fuel Standard, renewable diesel can deliver lifecycle greenhouse gas emissions roughly 70% lower than conventional diesel, depending on feedstock and production pathway. For companies committed to comprehensive greenhouse gas accounting, those figures are material. And because HVO produces less carbon monoxide, nitrous oxide, and particulates than traditional diesel, it benefits local air quality. The Supply Constraint Is Real and Worth Naming Most HVO coverage overlooks a practical limitation: the distribution infrastructure is not yet mature. In certain US markets, HVO availability during an emergency is not guaranteed, and operators that commit to it need a contingency plan for such situations. In practice, that means maintaining supplier relationships for conventional diesel as a fallback, not as a primary fuel strategy. That supply gap is also an argument for committing publicly rather than waiting for it to close on its own. Demand signals matter. The more operators adopt HVO, the faster distributors invest in coverage. Waiting for infrastructure to mature before committing is a self-defeating position if the entire industry takes it. Getting It Through Your Organization Moving from concept to commitment requires financial modeling, engineering validation, and sign-off from both operations and sustainability leadership. That process is appropriate for any change touching the generator fleet and should not be rushed. What made it tractable was that the case had three independent legs: operational (significantly reduced polishing and cleaner engines), financial (direct cost reduction), and environmental (improvements in lifecycle greenhouse gas emissions). Each leg could support a separate conversation with a different stakeholder. That multi-disciplinary structure is what transforms a niche fuel proposal into an enterprise commitment. For operators evaluating a similar move, start with your fuel polishing spend. Build the financial model first, then layer in the lifecycle emissions data. The engineering conversation around compatibility and supplier qualification is more straightforward than most expect. HVO is a drop-in replacement for conventional diesel with no generator modifications required. The Assumption Worth Challenging Sustainability conversations in our industry tend to cluster around high-capital initiatives like cooling architecture and PUE optimization. Those are important. They also require years, significant investment, and, in many cases, factors outside operational control. What this experience reinforced is that meaningful gains often lie within operational baselines that have never been examined. Fuel type is one of them. It has been the answer to a question most operators have not thought to ask, not because the answer is difficult, but because diesel has always been the default. The change does not require a new facility, a new budget cycle, or new technology. It requires a vendor conversation, a financial model, and the willingness to treat a decades-old assumption as a variable.