Often termed the country’s “silent renewable,” hydropower is the nation’s largest renewable electricity resource, providing 7% of total generation. Hydropower’s many supporters – 81% of U.S. voters favor maintaining existing hydro, according to a recent National Hydropower Association poll – value its low-cost, reliability and ability to integrate intermittent renewable resources.  Critics argue that hydropower is not environmentally-friendly and, if included in state Renewable Portfolio Standards, will reduce the growth of renewables like wind and solar power.

Historically, the U.S. Army Corps of Engineers and the Bureau of Reclamation built the vast majority of major federal dams with integrated hydroelectric generating plants in the United States. Hydroelectric dams contribute billions of dollars each year in revenue to the U.S. Treasury and provide enough generating capacity to power 72 to 96 million homes (NHA) across 38 states (EIA). However, many of these plants are operating well beyond their design life, and as a result, experiencing decreasing reliability. Moreover, high operational demand from a new era of integrating variable generation and evolving energy imbalance markets is increasing the prevalence of costly unplanned outages.

At the national level we need to prioritize hydropower and reaffirm its place in the conversation about renewables. Significant capital is necessary to rehabilitate and modernize the United States’ hydroelectric dams for reliable operation well into the future. Unfortunately, funding streams in the federal budget over the past 20 years consistently have been inadequate to maintain this entire critical infrastructure at acceptable levels of performance and efficiency.

What role should hydropower play in the nation’s energy future? Should there be a greater emphasis on funding the rehabilitation and modernization of hydropower dams? What are the implications of the aging hydropower dam infrastructure on the nation’s economic growth and energy security?