Batteries Undercut Gas and Diesel on Flexible Capacity for Data Centres, S&P Global Finds

Battery storage has emerged as the least expensive option for providing flexible power to large data centers when total costs are measured across a full 25-year lifespan, according to a new analysis by S&P Global commissioned by energy storage firm Fluence.

The report, titled “The Real Cost of Power,” modelled a 390 MW data centre in Texas, Ireland and Australia. The costing runs over 25 years of service and takes in capital and operating outlays, the scheduled replacement of battery units, decommissioning and carbon risk.

The cost gap is most pronounced in the flexible-capacity segment. In Ireland the battery option works out at $136 million across the project’s life, while diesel backup reaches $794 million and gas sits between them, at $432 million. In Texas, a 240 MW two-hour battery installation costs less than one-third the price of an equivalent gas turbine and roughly one-sixth that of diesel generation.

The authors make the yardstick itself their argument: what matters is not which kit carries the lowest invoice today, but which leaves the operator best off once the asset’s whole working life and its risks are added up.

Real-world deployments illustrate the trend. Calibrant Energy’s 31 MW/62 MWh installation at a flooded quarry site let an Aligned Data Centers campus of 72 MW start up in Oregon while the utility’s own grid reinforcement was still pending. In Tennessee, xAI’s Colossus 1 facility relies on a 150 MW / 600 MWh installation for backup power, frequency regulation, and peak shaving.

Regulatory frameworks are reinforcing the shift. Ireland now requires new data centers to match their import capacity with on-site generation or storage, while Texas has opened a Batch Zero connection route under Senate Bill 6, under which an operator can put its own batteries and its ability to shed load on the table when connection terms are negotiated.

Source: pv Europe