New England's Largest Conventional

Hydropower Generator


Hydropower is one of the most enduring, proven, and reliable ways to produce energy, embracing the power of flowing water to generate carbon-conscious renewable energy. Great River Hydro's diverse facilities have contributed significantly to New England's power grid for over a century. Our sustainable hydropower systems in New Hampshire, Vermont, and Massachusetts have continued to safely and reliably generate electricity at times when our region's consumers and industries need it the most. Great River Hydro and its dedicated and experienced community-based employees will continue to lead in the 21st century as the world demands more carbon-conscious energy sources.


The renewable power generated by Great River Hydro facilities can power over 213,000 homes each year, but the story doesn’t end there. Unlike solar, wind, and run-of-river hydro, Great River Hydro’s renewable power is on-demand.  And unlike batteries, pumped storage hydro, and other storage resources, our reservoirs store energy without consuming electricity from the grid. Carbon-free, dispatchable power is critical to achieving a reliable and sustainable power grid in the 21st century.


Hydropower from Great River Hydro displaces 680,000 tons of carbon dioxide annually. 11 out of our 13 generating facilities are certified by the Low Impact Hydropower Institute, sustainably embracing the power of flowing water.


Great River Hydro’s large reservoirs and sequential generating stations allow us to store vast quantities of energy and efficiently dispatch it into the grid when it is needed the most – not just when the sun is shining or when the wind is blowing.  Our fast-start, on-demand capability provides carbon-free reliability to our region’s electricity supply as more variable solar and wind generation enter our region’s energy mix.


Great River Hydro generates renewable energy right here in New England, for New England. Locally-produced power means our stations are run and supported by your neighbors through direct employment and contracted services with local businesses. Great River Hydro supports 51 towns across the region with significant property tax revenue and we give back through partnerships and contributions to related community causes.

Conservation & Recreation

Great River Hydro is privileged to own nearly 30,000 acres of land around its facilities and reservoirs, mostly protected under conservation easements. We steward these resources to ensure safe public access for passive outdoor recreation and for the protection of natural resources. Miles of trails, dozens of picnic areas, and twenty boat launches ensure area residents and visitors enjoy the Connecticut and Deerfield Rivers. Every year, our lands and reservoirs along the two rivers host more than a half million guests, protecting the character of local communities while supporting their economies for generations to come. Harriman Dam pictured right

Our History

Great River Hydro’s facilities have an amazing history. Conceived at the dawn of commercial electrification over a century ago, clean, reliable, renewable energy has been powering New England ever since. And Great River Hydro stands ready to power our future as well.


Great River Hydro operates 13 generating stations and 3 storage-only reservoirs located along the Connecticut and Deerfield Rivers in New Hampshire, Vermont, and Massachusetts. Unique to New England, our system pairs vast amounts of reservoir storage (including the two largest facilities of their kind in the region) with highly coordinated, sequentially located facilities that efficiently use the water multiple times as it travels downstream, representing 40% of the capacity and 23% of the total electricity generated from conventional hydropower in New England. Explore over 310 miles of rivers, the source of our power.