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Non-powered Dam Development Opportunities


Although more than 92,000 dams are scattered across the United States, the vast majority — over 89,000 — do not generate electricity through hydropower. Researchers at the US Department of Energy’s Oak Ridge National Laboratory (ORNL) are assessing the feasibility of retrofitting some of these non-powered dams (NPDs) to potentially generate enough clean energy to add 12 gigawatts of electricity to the U.S. power grid.

In its new report, ORNL identifies key development challenges, including aging infrastructure, dam design limitations, costs, timelines, and environmental considerations. The goal is to accelerate design approaches and innovations that increase energy from hydropower while ensuring environmental compatibility and economic feasibility.

Because these dams already serve a variety of functions including irrigation, navigation, water supply, flood control, and recreation, NPD retrofits must accomplish several priorities:

  • Maintain or improve existing functionality of dam and stream
  • Enable new retrofitted facility to reliably generate electricity
  • Minimize changes to water surface level and surrounding environment and ecosystem
  • Ensure each retrofit is cost-effective


ORNL researchers have taken a four-pronged approach in their assessment and ongoing study, including hosting key stakeholder workshops, creating two new NPD classification tools, updating the NPD resource assessment, and summarizing NPD-specific design strategies that follow the Standard Modular Hydropower development framework.

ORNL conducted the virtual workshops between Dec. 2020 and Dec 2021. The first workshop explored challenges and opportunities related to NPDs and brought together a variety of stakeholders to discuss ways to improve classification and data access. The three following workshops presented the concept and beta version of newly developed NPD classification tools – the NPDamCAT App and NPD Explorer App – to solicit feedback and suggestions for improving the research products.

Design strategies were built upon the Exemplar Design Envelope Specification for Standard Modular Hydropower Technology framework, and provide a holistic approach to NPD retrofits toward reducing the uncertainty of and costs related to site-specific design challenges – acknowledging that no one solution will meet all needs.

Taken all together, these efforts enhance understanding of NPD retrofit opportunities and design considerations.


Representing early-phase efforts of the Department of Energy’s Water Power Technologies Office to address the challenges and opportunities of NPD development, this research aims to supply high-quality data and the means to explore NPD information, better inform stakeholders of economic and environmental requirements, and begin to address the dual goal of reliable low-carbon energy and environmental sustainability.

Next Steps

ORNL researchers will report on their assessment of NPDs, which uses advances in hydrologic modeling, improved elevation data resolution and coverage, and updates to infrastructure inventories to refine estimates of NPD potential.