Information and Communication Technologies (ICTs) offer many opportunities for energy saving, such as optimising energy use in buildings and industrial processes, but the continuing increases in the number, power and range of applications of ICTs may act to increase energy demand. To date, however, there have been few rigorous, empirical estimates of the net impact of ICTs on energy demand in different sectors. In this paper, we provide such estimates using a panel dataset of 28 sectors in 17 OECD countries over 13 years. By estimating equations for the share of energy in variable costs, we are able to derive estimates of the elasticity of energy use with respect to ICT capital services – both for the whole sample and for individual sectors. Our results suggest that investment in ICT is associated with a modest reduction in energy demand, with the impact being much larger in ‘service’ sectors. These results appear robust to a variety of specifications. The findings are relevant to the role of digitalisation in delivering net-zero emissions, and to the panel session on energy demand.