Current Trends in Technological Advancements and Regulatory Updates

The Latest Developments

Pumped storage hydropower (PSH) is experiencing a resurgence in project development across the globe, driven by the increasing need for grid stability and renewable energy integration. In the United States, 67 new proposed PSH projects are currently in various stages of planning across 21 states, representing over 50 GW of new storage capacity. These projects are designed to be environmentally friendly, with many being off-river or closed-loop systems, which have minimal impacts on natural waterways.

In addition to the U.S., other regions worldwide are also seeing significant PSH development. For example, in Europe, the Obervermuntwerk II project in Austria and the Nant de Drance project in Switzerland are notable examples of new PSH installations that leverage advanced technologies to enhance efficiency and capacity. China recently completed the startup on the 12th and final unit at the 3,600 MW Fengning Pumped Storage Project, making it the largest PSH facility in the world.

Life Cycle Assessment of Closed-Loop Pumped Storage Hydropower in the United States by Timothy R. Simon, Daniel Inman, Rebecca Hanes, Gregory Avery, Dylan Hettinger, and Garvin Heath; Environmental Science & Technology 2023 57 (33), 12251-12258, DOI: 10.1021/acs.est.2c09189

Technological Advancements

Technological advancements are transforming PSH into a more flexible and efficient energy storage solution. Key innovations include:

Variable Speed Pump-Turbines: These advanced turbines allow for more precise control of power generation and consumption, providing greater flexibility in responding to grid demands. Variable speed technology enables PSH plants to adjust their output more finely, which is particularly valuable for balancing intermittent renewable energy sources.
Advanced Control Systems: Modern control systems use artificial intelligence and machine learning to optimize the operation of PSH plants. These systems can predict grid demands and adjust operations in real-time to maximize efficiency and reliability.
Rapid Ramping and Startup: Other PSH configurations, including ternary machines and quaternary configurations, are being developed that provide even faster startup, rapid shifting from pumping mode to generating mode, and utilization of recirculating flows (“hydraulic short-circuit"), which would make these new PSH configurations even more flexible for responding to intermittent renewable generation and rapidly shifting load demands.

Advanced adjustable speed technology allows PSH to provide an even greater range of fast ramping, both up and down, and frequency regulation services in the generation and pumping modes.

Emerging Trends

Several emerging trends are shaping the future of PSH:

Hybrid Systems: There is a growing interest in hybrid energy systems that combine PSH with other renewable energy sources, such as wind, solar, and hydrogen. These hybrid systems can optimize energy storage and generation, providing more stable and efficient power solutions.
Floating Solar: Floating solar systems are easily integrated into upstream and downstream reservoirs at pumped storage facilities without occupying lands that would otherwise have alternate uses.
Digitalization and Smart Grids: The integration of digital technologies and smart grid solutions is enhancing the efficiency and responsiveness of PSH systems. Advanced data analytics, predictive maintenance, and real-time monitoring are improving the operational performance of PSH plants.
Market Mechanisms: New market mechanisms and financial models are being developed to better recognize and reward the services provided by PSH. This includes compensation for grid stability services, capacity payments that properly compensate PSH’s resource adequacy value, and incentives for renewable integration.
Innovations: Proposed innovative designs, such as underground reservoirs, modular PSH units, and seawater PSH, could reduce environmental impacts and expand the range of feasible project sites. These designs would enable installing PSH in locations where two traditional surface reservoirs would be impractical or environmentally unacceptable.

The Lewis Ridge Pumped Storage Project represents a new era of jobs and economic growth for Southeastern Kentucky. It builds upon the region’s energy-producing legacy and skilled workforce to develop critical infrastructure that will power the nation for future generations.

There is huge availability for off-river pumped storage sites. The Australian National University Atlas identifies over 600,000 potential off river greenfield sites globally outside protected areas. Even if only 1 in 100 of those are viable, that is still sufficient additional capacity several times over. IHA 2024 World Hydropower Outlook report

Regulatory Updates

Regulatory frameworks are evolving to support the development of PSH, but challenges remain. In the United States, the Federal Energy Regulatory Commission (FERC) has introduced expedited licensing processes for closed-loop PSH projects to reduce permitting times from several years to months. The FAST-41 process can also help keep federal agencies working on an efficient review timeline. However, navigating these regulatory landscapes requires careful planning and coordination with multiple stakeholders.

Engagement with land owners, agencies, tribes, and other stakeholders early and often throughout the development process is key to success.

Regional Market Updates

The drivers for PSH development vary significantly by region and are influenced by local energy policies, market structures, and grid needs. Here’s a closer look at some key regions

US Western Grid: States like California and Arizona are leading the way in planning for PSH development, driven by ambitious renewable energy targets and the need to mitigate grid instability caused by high solar penetration. For example, the CAISO (California Independent System Operator) market has seen increased PSH activity to address the "duck curve" issue, where solar generation drops sharply in the evening as demand rises.
US Southeast: States and companies in the Southeastern United States are actively considering PSH development to complement new solar development and significant increases in load. PSH will prove invaluable for capturing extrasolar during the day and base-loaded nuclear at night to meet increased demand as the Southeast grows in population.

In summary, the current trends in pumped storage hydropower highlight its critical role in supporting a sustainable and resilient energy future. By leveraging technological advancements, navigating regulatory landscapes, and addressing regional market dynamics, PSH can continue to be a cornerstone of the transition to renewable energy.