SMR

Small modular reactors (SMRs) are nuclear reactors designed to be factory-built in standardised units, typically producing up to 300 MW of electrical output per module, compared with the 1,000 MW-plus of conventional large-scale nuclear. Their smaller footprint and modular construction make them theoretically better-suited to distributed power demands — including large data centres — than conventional nuclear.

In the data centre sector, SMR conditional power agreements have grown rapidly on paper: the IEA's April 2026 report cited a rise from 25 GW at end-2024 to 45 GW by April 2026 — a near-doubling of committed capacity in sixteen months. Microsoft, Google, and Amazon all announced SMR agreements in 2023-2025. The qualifications are significant, however: no commercial SMR has yet powered a data centre anywhere in the world. All agreements are conditional on reactor designs obtaining regulatory approval, securing financing, and completing construction — processes that typically take a decade or more.

The SMR pipeline for data centres has been described by analysts as a real but distant solution. Near-term power needs are being met with gas turbines. SMRs represent a long-cycle bet on low-carbon firm power that is commercially attractive in theory but faces substantial execution risk.