Overcoming Tough Conditions To Bring Community Solar To Local Residents

Terrasmart and Nexamp partnered together to install a 6.5-MW community solar project in Rumford, Maine—located north of Portland in Oxford County. This community solar project benefited residents, non-residential customers, local businesses, and municipal organizations by allowing them to subscribe to a solar energy site. In return, the subscribers would receive credits on their monthly utility bills—resulting in significant annual savings on their electric costs.

“This solar energy project in Rumford will help the town and its neighbors save on its electricity bills and reduce their dependence on fossil fuels,” says Dan Burgess, Director of the Governor’s Energy Office.

When looking for a partner to design and install a single-axis tracker system, many elements had to be considered. With annual snowpacks frequently exceeding 25 inches and an average of 59 days per year covered in snow, local winters routinely hit freezing temperatures. In addition to Maine’s brutal winters, the site’s slopes and rocky soil were not ideal for most racking systems. Given Terrasmart’s expertise in the Northeast and with tough terrain, we were selected to design, engineer, and install the foundation and racking for the project.

Rocky and frost-susceptible soil made ground screws the only viable foundation option as they eliminated 100% of the site’s refusal risk. With temperatures reaching -30 degrees in the winter months, frost heave and frost jacking were a key concern that could threaten the lifespan of a solar site. Although driven piles are a common foundation used in solar projects, the 50-inch frost depth on the site made it clear that ground screws were the preferred solution for counteracting the risk of frost heave and protecting foundation integrity against the elements.

The built-in flexibility of our TerraTrak 2P racking helped to overcome the undulating terrain and slopes present on the site. With a state average snowfall of 50 to 80 inches, weather was a key influencer when selecting and designing a solar tracking system. The TerraTrak 2P system was designed and engineered to withstand 105 mph wind loads and 100 psf snow loads. As an industry leader in accommodating high slopes, the 20% grade slopes were an easy obstacle to overcome.

Engineered to maximize energy production and revenue, more than 5,000 ground screws and 215 TerraTrak 2P single-axis rows were used to support the project’s 16,068 bifacial modules.

As time was of the essence, Terrasmart was charged with installing the ground screws and racking during fall and winter. Because snow comes early in Maine—usually in November—most of the work took place in frigid temperatures after the ground was frozen.

Our installation team used Terrasmart’s proprietary ground screw machine to install the screws quickly and efficiently, while TerraTrak’s telescoping screw extensions offered best-in-class field adjustability to help streamline the build on variable slopes.

As a result, the project was completed on time, without any delays.

“Our team is proud to have partnered with Nexamp in building this milestone solar project for the Town of Rumford, Maine,” says Terrasmart President Ed McKiernan. “The collaboration between the teams at Nexamp and Terrasmart thrived through the tough wintery conditions experienced during installation, so we could collectively help deliver a more sustainable future for the community of Rumford, and ultimately support Maine’s renewable energy goals.”

Terrasmart was able to help the developer meet project deadlines by ensuring an on-time delivery and installation process—even in the heart of winter. Applied research and advanced design engineering facilitated by our engineering team resulted in a customized tracker solution to suit Maine’s challenging weather and terrain. To mitigate long-term project risk, Terrasmart’s patented ground screws were used as the key foundation for the project to minimize frost heave and heighten project longevity.

The Rumford project—which is expected to offset more than 12 million pounds of CO₂ annually—has proven to be a valuable economic investment for the town, as it has generated jobs, increased energy savings, and reduced emissions.

“Rumford is an ideal place to live and work, and we are committed to maintaining our beautiful landscape while ensuring that we do the right thing for the environment and our residents,” says George O’Keefe, Economic Development Director, Town of Rumford.