CONWAY — During its fourth hearing on BlueWave Solar’s plans for a 20-acre solar array on Roaring Brook Road, the Planning Board considered the slope, screening and safety features of the proposed design before continuing discussion to a fifth hearing.
The application for the project on Ronald Boyden’s farmland describes a 4.99-megawatt system with solar panels set 10 feet above the ground, along with a battery energy storage system, a 20-foot-wide gravel access road and a stormwater basin.
The solar array would be a dual-use system, allowing landowners to continue using the site for farming, with animals able to graze under the panels. The solar panels would be spaced with enough room for sunshine to reach the field below, according to Melinda Costello, a civil engineer with Weston & Sampson. Instead of fixed panels, the solar panels would move to follow the sun throughout the day.
The energy from the solar array would flow into the local electric grid. Eversource would then purchase the energy through the state’s SMART 3.0 Program, an incentive program for solar power developers.
BlueWave Solar reached out to Boyden as part of its “outreach efforts” to farmers in the state in accordance with the company’s “strong focus on agrivoltaics applications combining clean energy with sustainable farming,” Joel Lindsay, vice president of project development at BlueWave, explained in an email.
The slope of the solar panels continued to generate discussion on Tuesday night.
The town’s bylaw for commercial solar photovoltaic systems requires that the systems sit on slopes with grades of less than 15% while allowing the Planning Board to consider issuing waivers for slopes up to 18% “based on site-specific parameters.”
While board members interpreted the slope mentioned in the bylaw as the slope of the ground beneath the proposed panels, BlueWave Solar followed a different interpretation, which the board rejected, due to the company’s calculations not following the bylaw.
“Ground slope does mean something to us and it has implications on erosion,” Planning Board member Jeff Lacy said. To Lindsay, he added, “I would be surprised … if you’ve got any other towns that have acquiesced to your version of this slope definition.”
Moving forward, BlueWave Solar plans to remove from its design the solar panels that were proposed for areas with ground slopes above 18%. Costello presented a visual of the slopes that fall above 18%, and those between 15% and 18%. She and Lindsay described the importance of a waiver to keep the slopes between 15% and 18% as part of the design.
“For us, it’s important to use those areas that are 15% to 18%,” Lindsay said.
Given that the panels would sit on an established agricultural field instead of an area that would require trees to be cleared, Costello said the site “would be a good candidate for that waiver.”
For the next hearing, BlueWave Solar will work on calculating the percentage of the solar panels that have a slope between 15% and 18%.
When Planning Board member Cheryl Case echoed residents’ concerns from prior meetings about rainwater dripping off the solar panels, peer reviewer Chris Chamberland said he expects the Massachusetts Department of Environmental Protection (MassDEP) would not view the panels as “impervious” as long as they are spaced 18 feet apart as proposed.
“Vegetation is the key,” Chamberland said. “Grass is the best erosion control out there, so the fact that these posts get put in on a site that’s already well-vegetated helps.”
While the engineers have increased the screening from their original design to comply with the town’s bylaw that requires “large-scale solar facilities” to include a 30-foot screen of native trees and shrubs, Planning Board Chair George Forcier asked if the screening could stretch along Roaring Brook Road from Deerfield River Portage to Boyden’s farm barns to block Roaring Brook Road travelers from seeing the array.
At other hearings, residents have voiced concerns with the impact of the array on the beloved view of the farmland from Route 116 and Roaring Brook Road.
“That is a significant addition to screening,” Lindsay replied. “I’m very hesitant about that because I think it could be difficult to make it be that effective. I don’t want to interpret your own bylaw for you, but I don’t think that we’re obligated to make the array invisible necessarily. … I don’t think we can feasibly make the array invisible.”
Forcier agreed that the bylaw only requires solar array applicants to “minimize” the array’s visual impact.
Costello said extending the 30-foot-wide screening would lead to a “significant cost.” She added that Boyden tends to cornfields on the land that would block off part of the array. Planning Board associate member Jennifer Mullins noted the corn would only reach its full height for about two months.
The board also dug into the proposed battery energy storage system, a SolBank 3.0 model stretching 20 feet long and 8 feet high.
Forcier asked whether thermal runaway from the battery would melt through the cell into the ground. Thermal runaway occurs when a battery overcharges, short-circuits or undergoes damage that heats up the battery and can cause fires or explosions.
Lindsay and Kevin LaMalva, an engineer at Fire & Risk Alliance working with BlueWave Solar, said the system is intrinsically designed to contain a random event of thermal runaway. According to LaMalva, the system has undergone testing to confirm that it prevents runaway in one lithium iron phosphate battery cell from spreading to several adjacent cells.
Lindsay added that the lithium iron phosphate within the batteries resembles a gel, not a liquid; therefore, a concrete container for the system is not required. Chamberland echoed that the battery cells do not pose a “leak risk.”
“There are various levels of defense and depth to mitigate bad outcomes to that effect,” LaMalva said.
Lacy suggested BlueWave Solar move the proposed site for the battery energy storage system behind a barn on the property, claiming he has not heard any engineering factors that would prevent the relocation.
“I view it as one of the few things we can do for the people of Conway in this project that might ease the visual burden of this a bit,” Lacy said.
While Costello and Lindsay agreed to look into this possibility, Costello said the system’s equipment pad may threaten the barn’s foundation. Chamberland said barns often lack fire protection systems, potentially exposing the battery energy storage system to a fire risk.
Members of the Planning Board agreed to continue the hearing on the solar array to a tentative date of Tuesday, Aug. 11, at 7 p.m.
