skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 8. Design approaches: UPH. Final report

Technical Report ·
OSTI ID:6272989

The development of the design approaches used to determine the plant and overall layout for an underground pumped hydroelectric (UPH) storage facility having a maximum generating capacity of 2000 MW and a storage capacity of 20,000 MWh is discussed. Key factors were the selection of the high head pump-turbine equipment and the geotechnical considerations relevant to the underground cavern designs. The comparison of pump-turbine alternatives is described leading to the selection for detailed study of both a single-step configuration, using multistage reversible pump-turbines, and a two-step configuration, with single-stage reversible pump-turbines. Preliminary review indicated that the nominal head on the pump-turbines would be about 4600 ft. The major components for each of the two configurations, including the upper (surface) reservoir, shafts, heavy hoist, power plant and lower (underground) reservoir, were investigated for this nominal head of 4600 ft. Costs appropriate to nominal heads of 3800 ft and 5000 ft were also estimated to assess the impact of design head on overall project cost. The optimum nominal head for each configuration was determined, taking into account the cost/depth relationship and the head limitations imposed by pump-turbine and motor-generator design. Overall configuration layouts were finalized accordingly. The report recommends, as the basis for subsequent preliminary plant design, the adoption of the two-step configuration with single-stage reversible pump-turbines and an overall nominal head of 5000 ft. Some of the material given in this volume has been modified in the course of the preliminary plant design. The finally adopted arrangement is described in Volume 11, Plant Design - UPH.

Research Organization:
Potomac Electric Power Co., Washington, DC (USA); Acres American, Inc., Buffalo, NY
DOE Contract Number:
AC02-77ET28013
OSTI ID:
6272989
Report Number(s):
EPRI-EM-1589(Vol.8); ON: DE81030673
Country of Publication:
United States
Language:
English