Into the Woods: Solar in the Forest

• explore the number and location of solar projects in the region
• assess how much undeveloped land was lost to solar development

Solar energy reduces greenhouse gases and improves energy independence. Ground-mounted solar arrays can stabilize degraded land and provide job opportunities. According to the Solar Energy Industries Association, Rhode Island, Massachusetts, and Connecticut have a combined 6,469 megawatts of solar power (inclusive of the entire states). Over the next 5 years, the states are set to add 3,613 megawatts of solar power, representing an 80% increase from today.

Solar power is a necessary tool for reaching emissions reductions goals set in Rhode Island (RI), Massachusetts (MA), and Connecticut (CT).

Forests and natural ecosystems support key species and habitats, provide recreation and economic opportunities, filter drinking water, and provide resilience from flooding and extreme heat.

The  average forested acre  in RI stores 76 metric tons of carbon and absorbs an additional 1.3 metric tons of carbon from the atmosphere each year. Assuming this is the average for a forested acre throughout the Narragansett Bay Region, our  603,222 acres  of forest store 45 million metric tons of carbon, and absorb an additional 700,000 metric tons of carbon per year (equivalent to the annual emissions of 140,000 cars per year).  To put that in perspective,  Harvard Forest  found that MA forests capture carbon from the atmosphere equivalent to about 10% of the state’s emissions (100 million metric tons of carbon). Forests are critical for capturing and storing carbon from the atmosphere.

Yet, we are facing the loss of carbon capture from our forests to development of renewable energy sources, among other threats. Forest loss has accelerated in the last decade with the announcement of renewable energy targets and incentives for developers to keep costs affordable.

Nearly 4,000 acres of land, the majority of which is undeveloped (Figure 1A) have been cleared for solar projects in the Narragansett Bay Region. By far, most solar projects were installed in forested areas or cropland (Figure 1B).

Fragmenting forests for solar projects threatens one of the Narragansett Bay Region’s most unique habitats – core forests, which are contiguous areas of forest greater than 250 acres.  In 2021, the region had 239,333 acres of core forest, representing about 40% of the entire forested area of the region (603,222 acres). In 2008, before solar projects were tracked, the region had 265,229 acres of core forest. The Narragansett Bay Region lost 25,895 acres (10% loss) of core forest to development, including solar installations. The loss is from both direct development and fragmentation, when part of a core forest is developed, leaving the remainder less than 250 acres.

Core forests are the most intact forests and therefore, least impacted by humans. Species needing  intact and core forests  to thrive include the northern goshawk, scarlet tanager, red-spotted newt, and brook trout. Core forests are also key resting and feeding areas for migratory birds. The loss of core forest to development or fragmentation means the loss of habitat for these species, recreation opportunities, pollution reduction, and resilience to climate change.

Rhode Island recently passed  legislation  to protect core forests from solar development. Any core forest acres lost in RI between 2008 and 2021 are no longer protected from solar development. They will also not be protected by any future regulation to reduce development in core forests.

Altered land use changes how stormwater is transported and stored. Construction of the solar project requires clearing the land, which decreases its ability to trap and reduce stormwater flow. The now-cleared land may erode, further impacting waterbodies downstream. While states require developers to address stormwater flooding and control erosion, these methods may not fully protect the landscape ( Yavari et al. 2022 ).

There is a delicate balance that needs to be struck between development to match population and industrial growth and preservation, restoration, and protection of undeveloped land. Answering the question “what is the best use of the land” requires careful consideration of the development goals of the municipality, the desire for undeveloped land, and the long-term considerations of the population. Once a habitat is lost, it could take decades to centuries to come back, if it comes back at all.

The Association of Fish and Wildlife Agencies  summarized  a survey of member agencies from across the country. The detailed survey created a list of ideas that can be implemented to advance solar and protect nature. The highlighted suggestions encourage interstate collaboration, siting tools and guidelines, and monitoring regulations to understand environmental impacts.

• General geospatial siting tool that can be applied to solar siting to minimize impacts
• A certification or scorecard verifying low-impact projects
• State solar siting guidelines, including interstate collaboration
• Required early coordination between solar developers and state/municipal agencies to identify agency-approved recommendations to minimize impacts
• Pre- and post-construction monitoring to understand impacts of installation

NBEP is developing a database of information to help identify parcels of undeveloped land which would be the most beneficial to preserve. The solar data presented here will be combined with data on habitat and water quality, sensitive species and habitats, core forests, and other data identified by our partners. This work builds off an  analysis  done by students of Clark University and expands it to the entire Narragansett Bay Region.

NBEP will share additional information on the rate of solar development in the Narragansett Bay Region and the mechanisms used by the states and municipalities to balance the need for renewable energy and protected open space.