STRAIGHT ANSWER
How much electricity will U.S. data centers use by 2030?
Berkeley Lab's June 2026 update models a 649 TWh reference case for 2030, about 11.8 percent of forecast U.S. electricity, with a compounded uncertainty range of 521 to 843 TWh (9.5 to 15.3 percent). It is a scenario, not a forecast of water use.
The context
The range reflects uncertainty in AI adoption, hardware efficiency, and grid constraints. Electricity drives indirect water consumption, but the ratio depends on the generation mix in each region, so the electricity number cannot be converted to a national water number without that mix.
What this answer does not say
- That water use will grow by the same ratio.
- That 649 TWh is a prediction rather than a reference case with a wide range.