Pumped Storage – Poster Presentations
CLEAN CURRENTS 2026
Time: 11:00 AM - 12:00 PM
Day: 9/23/2026
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Details about each presentation and the speakers are below:
In this session:
Feasibility First: Integrated Technical–Economic Evaluation for Pumped Storage Hydropower
Framing the Inertia Revenue Potential for U.S. Hydropower and PSH
Feasibility First: Integrated Technical–Economic Evaluation for Pumped Storage Hydropower (HDR, Inc.)
Presented by Sam Kirsh, HDR, Inc.
Long duration energy storage is crucial for utilities to integrate intermittent renewable energy into the grid. Understanding which energy storage system can meet the varying purpose and need of the grid while delivering the lowest impact to ratepayers is a critical aspect of project development. Recent feasibility assessments completed for major utilities illustrate how multidisciplinary evaluation can support investment decisions for complex pumped storage hydro (PSH) infrastructure.
Robust feasibility assessment requires close coordination with engineering, environmental, operations, and financial stakeholders from the outset. For one recent assessment, engineering teams collaborated with economists to not only identify fatal flaws typical to pumped storage development, but to evaluate alternative configurations at a conceptual level that would be compatible with and appropriate to address the specific energy storage needs of the grid and locale associated with the project. This focused and integrated approach proved essential for characterizing PSH design and constructability risks, including reservoir siting constraints, long-term operational considerations, and informing technology deployment decisions.
Lifecycle cost and sensitivity analysis are tools that allow utilities to evaluate uncertainty and make informed decisions on their investments. In recent lifecycle cost analyses that included assessing storage technologies from an energy (MWh) perspective in addition to the traditional capacity (MW) perspective, PSH becomes increasingly cost-advantaged across long duration, large storage needs with longer lifecycles. Common financial metrics show PSH as a strong long-term resource when evaluated over realistic planning horizons. However, lifecycle cost does not tell the whole story. Hydropower with modular batteries, or small-scale batteries, may be a more cost-beneficial approach in some cases.
Sensitivity analysis is a crucial component in these evaluations. It captures uncertainty in key variables that influence project outcomes and helps identify the break-even conditions under which hydropower performs relative to other technologies. Considering a range of potential outcomes reflects a range of plausible futures, making recommendations more robust than a single point estimate.
The analyses also underscore the significance of federal tax incentives that vary for energy storage. These incentives can materially improve project viability for both greenfield and modernization PSH investments. Integrating these incentives into economic modeling is essential for capturing PSH's long-term value proposition.
Awareness of these studies is highly valuable to the hydropower industry, as they demonstrate that PSH remains a highly relevant, technically feasible, economically competitive, and strategically valuable resource, particularly when evaluated through a multidisciplinary framework.
Framing the Inertia Revenue Potential for U.S. Hydropower and PSH (Oak Ridge National Laboratory)
Presented by Rocio Uria-Martinez, Oak Ridge National Laboratory
Synchronous inertia, the kinetic energy stored in the rotating masses of synchronously connected machines, is one of the services provided by hydropower and PSH that is currently not remunerated in U.S. markets. Inertia plays an important role in maintaining frequency stability in the grid. Historically, U.S. electricity was predominantly produced by large synchronous generators (coal-fired, gas-fired, nuclear, and hydroelectric), resulting in an excess supply of inertia that did not need to be remunerated. In the past two decades, inverter-based resources (IBRs) such as wind turbines, solar panels, and batteries have been replacing synchronous generators. As a result, system inertia has been decreasing, and questions are arising about whether U.S. grids continue to be well prepared to maintain frequency stability after a large contingency such as the unplanned outage of their largest generator.
This work, part of a larger project developing a revenue model for long-duration energy storage assets such as PSH, estimates critical inertia needs in the three U.S. interconnections (ERCOT, WECC, and Eastern Interconnection) and proposes a methodology to estimate the price that could emerge in a potential inertia market if it were to be developed.
Critical inertia, the minimum level of system inertia needed to ensure that frequency responsive reserves have sufficient time to be deployed and prevent load shedding after the largest credible contingency, was estimated using industry-grade power system dynamic models. Results show that ERCOT is the U.S. grid where the existing IBR share is closest to the share at which simulations find critical inertia could be reached after the modeled contingency.
To bolster frequency stability in scenarios with high IBR penetrations, several alternatives are available: synchronous condensers, batteries, or grid-forming IBRs can provide virtual inertia. However, each of these resources is already providing other services into the grid, and therefore would only be willing to provide inertia if the remuneration received is at least as high as that from the next-best alternative. Based on this opportunity cost approach and using the PJM market as a case study, an inertia supply curve is developed. The inertia market clearing price that would result from the intersection of inertia supply and inertia demand (the critical inertia level) for various IBR shares and various levels of hydropower and PSH capacity will then be presented.
