How reversible pump-turbines can support grid variability: the variable speed approach

The integration of a large amount of intermittent renewable generation on the European grid requires the development of flexible electricity storage assets to provide time shifting and load balancing services. As a consequence, the pumped storage market is booming and new requirements for flexibility are appearing, with more challenging sites that need to be equipped. New technologies such as variable speed pumped-storage plants offer additional network flexibility and ancillary services compared with conventional pumped-storage plants.