Enforcing and improving water data reporting in the energy system is urgently needed

As it is a commentary we do not have a usual abstract Today’s energy systems are critically dependent on water for hydropower and thermoelectric power generation, which relies on a large amount of cooling water. However, even with increasing climatic pressures and growing concerns surrounding energy security, the availability of high-quality integrated water data sets remains poor (1, 2). This is surprising considering broad climate impacts on energy systems worldwide. Numerous regions experienced water-related power generation issues throughout the 2010 s, including coal generation during the 2015 Polish drought, repeated curtailment of French nuclear plants, and hydropower curtailment in the US, Romania, China, Ghana, and Brazil, among others (3). The 2022 heat waves saw broad water-energy issues across the EU, with France altering regulatory requirements to keep nuclear plants running (resulting in higher water temperatures) (4) and hydroelectric curtailment across several countries. There is clear evidence of impacts on energy security today (5) and how this issue is poised to become more acute into the 21st century (6, 7).