The Reality of Replacing Diesel Generators with Natural Gas, Energy Storage, Fuel Cells & Other Options

Diesel generators have long been the power backup for critical applications. However, with emerging environmental concerns, data center operators are looking to replace them with more sustainable options. In this paper, we assess many alternative technologies and narrow down our comprehensive evaluation to three technologies: natural gas generators, lithium-ion battery energy storage systems, and proton exchange membrane (PEM) fuel cells. These technologies are evaluated on their environmental impacts, cost, and other relevant criteria. Our analysis concludes that there is no obvious choice for a direct replacement of diesel generators for a long runtime backup-only application. The most practical alternatives today are using either natural gas generators or sustainable diesel fuel options. Lithium-ion batteries are not well-suited for 24-hour backup. While PEM fuel cells are the main contender from an emissions’ standpoint, this technology requires further cost reduction in CAPEX and fuel cost to become economically feasible.