Pumped Storage Hydropower US Market

Pumped storage hydropower US - Pumped storage is the dominant long-duration storage technology, providing large-scale energy shifting and grid services.

Pumped Storage Hydropower (PSH) is the largest and oldest form of utility-scale energy storage in the United States, accounting for approximately 97% of the nation's utility-scale storage capacity. It is a cornerstone technology for grid stability and the integration of intermittent renewable energy sources like wind and solar.

PSH Technology and Role in Grid Stability
PSH operates as a massive, water-based "battery" by managing the timing and balance of electricity supply. A typical PSH facility consists of two reservoirs at different elevations. During periods of low electricity demand and/or high variable renewable energy (VRE) generation (e.g., windy nights or sunny midday hours), cheap surplus electricity is used to pump water from the lower reservoir to the upper reservoir, effectively storing potential energy. When electricity demand is high, or VRE generation is low, the water is released back through turbines (often reversible pump-turbines) to the lower reservoir, generating electricity quickly.

In the U.S., PSH provides essential grid services that include:

Energy Storage and Capacity: PSH facilities in the U.S. currently possess a total capacity of approximately 23 GW across 42 sites, primarily located in just 16 states. The capacity of PSH can be quickly dispatched, providing crucial firm capacity (guaranteed minimum power delivery) estimated to be over 24 GW for all U.S. hydro facilities combined.

Grid Flexibility and Reliability: PSH can ramp generation up or down almost instantaneously, providing ancillary services such as frequency regulation and spinning reserves, which are vital for maintaining the electrical grid's frequency and voltage. This flexibility is increasingly critical as the proportion of variable wind and solar energy on the grid rises.

Transmission Congestion Management: PSH facilities can absorb surplus generation in high-production periods and dispatch power during peak times, helping to balance the grid and avoid transmission bottlenecks.

Capacity and Development Challenges
Despite its proven role and efficiency (often cited as the most efficient form of large-scale energy storage), new PSH development in the U.S. faces significant headwinds. While the U.S. Department of Energy (DOE) estimates that hydropower's total capacity can sustainably add an additional 50 GW by 2050, with about 36 GW of that being new PSH capacity, actual development is slow. Currently, 67 new PSH projects are planned across 21 states, representing over 50 GW of potential new storage capacity, but getting these projects to the finish line is challenging.

Pumped Storage Hydropower US

Q1: What is pumped storage hydropower?
A system that stores energy by pumping water uphill and releasing it to generate electricity.

Q2: Why is it important?
It acts as a large-scale energy storage solution for grid balancing.

Q3: Where is it applied?
Regions with high renewable integration and grid stabilization needs.