Research Paper: Pumped Storage Hydroelectric Power Plants: Issues and Applications

There is a growing interest to build pumped storage hydroelectric power plants in order to use them
for system regulation purposes. The high penetration of intermittent renewable generators requires
more system flexibility. This technology could provide this flexibility to the electricity system. Several
questions could occur before implementing this type of project, like:
- Is the pumped storage facility a generation unit, which should compete with other generators on
the ancillary service market?, or this technology should be classified as system regulation facility
(owned, operated by TSO - consequently the cost of investment and operation should be covered by
the system operation charge)?
- Should the pumped storage facility pay network/system charge in both ways of operation
(purchasing electricity for pumping/storing and generating/delivering electricity to grid), or "only"
one way?