The hydrologic and economic feasibility of micro hydropower upfitting and integration of existing low-head dams in the United States

The integration of hydropower facilities on existing low-head, non-Federal dams and their subsequent tie to regional electricity grids may serve as a useful de-centralized component of renewable energy integration in the United States. Thousands of low-head dams do not provide power and thus present few benefits with significant costs, including safety liability, fragmentation of river ecosystems, and persistent economic burden induced on state agencies due to regular inspection requirements. We conducted a feasibility study in the Piedmont region of North Carolina cataloguing over 1000 non-Federal dams with hydraulic head ranging from 4.6 m to 10.7 m (15 ft to 35 ft) and power capacity <300 kW ("micro" hydropower). Generation potential, greenhouse gas reductions, and financial viability were refined for 49 low-head dams over a 30-year life cycle using industry standard software (RETScreen4). Results suggest that most of these dams are not financially viable for energy production under cost structures evaluated at the time of this study. However, our results indicate that some low-head dams may be viable for energy production if provided funding opportunities comparable to the concurrent wind and solar markets. - Highlights: • We assess opportunities to leverage existing low-head dams as energy resources. • We determine the viability of upfitting low-head dams using a run-of-river approach. • Energy generation on existing low-head dams is most affected by flow availability. • Micro-hydropower upfitting may be viable if provided subsidized energy pricing