Seth Lykins

Date of Award

January 2023

Document Type


Degree Name

Master of Science (MS)


Energy Engineering

First Advisor

Olusegun Tomomewo


Clean and sustainable energy sources must comprise a greater share of the global energy portfolio in the future, in order to support a growing population while reducing the anthropogenic effects of traditional energy production. Solar and wind-based generation methods, frontrunners of the energy transition, are intermittent by nature. This presents a challenge in the effort to replace dispatchable fossil fuels with a chiefly renewable energy portfolio. Yet this challenge can be met with appropriate storage, which must be scalable, reliable, sustainable, and financially feasible through implementation of multiple services. Pumped hydro energy storage systems (PHESS), with its colossal scale and uniquely mature technology, are well suited to complement the required level of intermittent production.Pumped hydro currently represents the vast majority of stored energy, both in the US and globally. Yet while other energy storage methods are experiencing exponential growth—most notably lithium-ion battery storage—construction of new PHESS sites has been essentially nonexistent for the last three decades. This is in part due to long construction times and significant regulatory hurdles, along with distinctive siting requirements. Recent studies have found that closed-loop storage projects offer a wealth of opportunities for off-river locations, as well as lower ecological impact, fewer regulatory hindrances, and reduced time and expense of construction. When selecting from the vast array of closed-loop possibilities, the chief consideration should be cost effectiveness of the projects. Studies of potential closed-loop PHESS sites have employed cost models by calculating costs of the basic physical components of each hypothetical project; however, this was done at a high level to screen out illogical site choices, and thorough valuation of the potential sites was not performed. The next phase should be to isolate the most favorable prospective closed-loop sites, and conduct detailed valuation analysis based on all available data for their individual locations and circumstances. While this has been largely absent in literature, the means to perform such analysis are available within the Pumped Storage Hydropower Tool (PSHVT), developed by the US Department of Energy as part of the HydroWIRES initiative. The objective of this work is to conduct comprehensive valuation analysis of a selected closed-loop PHESS case study in the early stages of development, using the PSHVT for guidance. Through modification of parameters necessary for such valuation, insights will be gained on the most critical aspects of PHESS projects and potential barriers to their development. The results of this study will be useful to prospective stakeholders, including investors, developers, regulating bodies, end users, and others. This work seeks to bridge the gap between hypothetical closed-loop, off-river sites and the realistic valuations of such projects, which will help in the progression toward a cleaner, more resilient, and renewable energy future.