Data centres have significant potential to improve energy efficiency, to operate flexibly and to use renewable energy. Since data centre capacity and electricity demand are expected to rise significantly, this potential will only grow—targeted policies are required to tap into it. Various studies show a broad portfolio of technologies and measures available to data centres for sustainable operations. Based on our interviews with key experts and industry players in the advanced digital economies of China and Germany, several barriers hinder efforts to improve the flexibility and renewable energy uptake of the data centre industry. Improving energy efficiency has been addressed through policy, sometimes to the detriment of flexibility. In the future, we expect price differentials on wholesale electricity markets to drive flexible operations. However, prices will not be enough; this study shows that it will require a range of targeted policies aimed at increasing awareness among energy and data market stakeholders, improving administrative and market incentives and removing barriers to flexibility.