Unlocking Small-scale Hydropower using Water Infrastructure for National Energy Security

Reliable local energy generation and long-duration energy storage are critical to balancing peak demands and providing distributed emergency backup near both urban and rural populations. However, small-scale (< 10 MW) hydropower faces barriers, including siting, permitting, water availability, and institutional issues. Drinking water, wastewater, and stormwater utilities across the country are moving billions of gallons of water daily. They own and operate existing, sometimes under-utilized, infrastructure that can be reconfigured for energy purposes at low cost and with minimal disruption to the environment. Research to unlock these opportunities would address the "water for energy" and "energy for water" focus areas by exploring and expanding opportunities to implement small hydropower integrated with water systems.

Small-scale hydropower can be integrated into water infrastructure in at least two ways: 1) in-conduit hydropower and 2) pumped storage hydropower (PSH). For both approaches, existing infrastructure, with relatively minor investments, can be reconfigured to provide revenue generating, near-continuous, distributed energy production using in-conduit hydropower and/or for resilient, cost-efficient distributed energy storage for emergency use, demand response, or peak shaving capacity using PSH. With limited exceptions, in-conduit hydropower and water-integrated PSH have been largely ignored by both the water and energy sectors.

Over the next 3-5 years with DOE support, researchers could explore potential locations and configurations (including in-conduit hydropower and different PSH technologies), demonstrate novel configurations and technologies, advance national-scale screening tools, quantify aggregate storage and generation potential by combining analytical site screening with techno-economic modeling and engage stakeholders through a Community of Practice, ensuring that soft costs, policy incentives, financing strategies, risk mitigation, and institutional challenges are considered and addressed early, accelerating adoption.

Success will be measured by both technical milestones and system-level outcomes related to technical performance (e.g., efficiency, cost); energy resilience (e.g., reduced grid congestion and peak demands); water resilience (e.g., reduced freshwater demands); economics (e.g., new revenue streams for utilities; lower costs for ratepayers); and scalability (e.g., access to feasibility information to speed adoption).