Natural gas supplies more than 40% of the electricity used by data centers in the United States, according to the International Energy Agency's analysis of energy supply for AI. Renewables provide 24%, nuclear power around 20%, and coal around 15% of the US data center supply mix, the agency found.

Gas is also set to deliver the largest share of new supply. In the IEA's base case, natural gas adds more than 130 TWh of electricity for US data centers between 2024 and 2030, while renewables add 110 TWh. The agency expects the first small modular reactors to come online after 2030, and it noted that technology companies have so far made plans to finance more than 20 GW of SMR capacity. By 2035, low-emissions sources are projected to account for more than half of the electricity supplied to US data centers.

The US mix differs from the global picture. Worldwide, coal currently provides about 30% of data center electricity, renewables about 27%, natural gas 26%, and nuclear 15%. Global electricity generation for data centers is projected to rise from 460 TWh in 2024 to more than 1,000 TWh in 2030 and 1,300 TWh in 2035, with renewables growing at an average of 22% a year through 2030 and meeting nearly half of the added demand.

The IEA's sensitivity cases show a wide range of outcomes. Global data center supply in 2035 would reach about 1,100 TWh in a high-efficiency case, 790 TWh in a headwinds case, and nearly 2,000 TWh in a lift-off case.

The accompanying chart, based on IEA data, compares the electricity sources supplying data centers in the US, China, and worldwide in 2025 and 2035.

Source: International Energy Agency -- https://www.iea.org/reports/energy-and-ai/energy-supply-for-ai