Baseload power refers to the minimum, constant level of electricity demand on an electrical grid, typically the load that persists 24 hours a day, 365 days a year. Baseload generation is traditionally supplied by power plants that are economically optimized for continuous operation at high capacity factors, with low variable (fuel and O&M) costs that make them the cheapest sources of energy when running steadily. Nuclear power has historically been the premier baseload technology, with the U.S. fleet operating at capacity factors exceeding 93%, followed by large coal plants and combined-cycle natural gas. The economics favor running these plants continuously and using peaking plants (combustion turbines, hydroelectric storage) to handle demand fluctuations above the base level.
The concept of baseload is experiencing a renaissance in the context of data center power demand, which has become the primary market driver for SMR deployment. Data centers require extraordinarily reliable, 24/7 power supply with minimal interruption, and the exponential growth of AI training and inference workloads is projected to push global data center electricity consumption from 460 TWh in 2024 to 1,300 TWh by 2035. This demand profile is perfectly matched to nuclear's baseload characteristics. Microsoft's 20-year PPA for the full 835 MW output of the Three Mile Island restart, Amazon's engagement with X-energy for Xe-100 modules, and Google's 500 MW Kairos Power fleet deal all explicitly target nuclear's baseload reliability for data center applications.
TerraPower's Natrium design illustrates how modern SMRs are evolving the baseload concept. The reactor itself operates as a steady-state baseload source at 345 MWe, but the integrated molten salt energy storage system allows the plant to dispatch up to 500 MWe during peak demand periods, effectively providing both baseload and load-following capability from a single facility. Meta's January 2026 agreement for up to 8 Natrium plants specifies 2.8 GW of baseload capacity plus 1.2 GW of storage-enabled peak capacity. This hybrid approach addresses the concern that inflexible baseload generation is incompatible with high-renewable grids, positioning nuclear SMRs as the dispatchable clean firm power that grid operators identify as essential for maintaining reliability as intermittent renewable penetration increases.