The electricity powering data centres is cleaner at some times and places than others, depending on how much comes from wind, sun and other low-carbon sources. Carbon-aware computing shifts flexible tasks, such as large batch jobs, to when and where the grid is greenest.
By timing heavy but non-urgent work for cleaner power, operators cut emissions without new hardware. It relies on forecasts of grid conditions and only suits tasks that can wait or move, so it does not help time-critical services, but for the large share of computing that is flexible it is a low-cost way to reduce environmental impact.