BOSTON -- Since the Department of Energy Resources rolled out updated regulations for a solar energy development program in April, lawmakers and farmers have been weighing in against a section of the new rules that they say could endanger dozens of shovel-ready solar projects in Massachusetts.

Nowhere more so than in Bristol and Plymouth counties.

The updated regulations for the state's Solar Massachusetts Renewable Target (SMART) incentive program, which is designed to facilitate solar projects by ensuring financing, double the program's capacity, expand eligibility criteria for low-income solar projects and encourage the adoption of energy storage technology.

But the new rules would also disqualify solar power installations on land designated as priority habitat, core habitat or critical natural landscape, and that provision could spell the end for projects that are already under development, Rep. Tom Golden, the House chairman of the Committee on Telecommunications, Utilities and Energy, said.

"Multiple stakeholders in the solar developer community have expressed that this expansion of ineligible land use will effectively cancel several shovel-ready projects, slow the growth of new projects, and be potentially counterproductive to the environmental goals that it seeks to accomplish," Golden wrote in a letter to DOER and Energy and Environmental Affairs Secretary Katie Theoharides. "Existing projects have already invested a significant amount of time, capital, and resources, and this regulatory change - if implemented - will result in stranded investment, job losses, millions of dollars in foregone municipal property taxes, and even possible commercial development of land that could have been preserved through economic incentives previously offered through the state's solar policy."

Golden suggested that DOER amend the regulations to maintain the prohibitions on projects on core habitat and priority habitat land, but that the department lift the ban on projects on land designated as critical natural landscape.

"Such a balance will help us preserve our natural resources in tandem with supporting a thriving solar industry," he wrote.

A DOER official said the department noticed that it received a disproportionate number of applications for solar projects on open space, and that it has been signalling throughout the SMART program review that it would need to find a more appropriate balance between promoting residential and commercial solar projects, and also the environmental and natural habitat benefits of leaving open space open.

In the updated regulations, DOER expanded the SMART program's capacity from 1,600 to 3,200 megawatts, which the administration said "will create a stable runway for growth of solar to continue" in Massachusetts. DOER also said in April that the update expanded the eligibility requirements for agriculture to include a wider variety of farmland.

In its comments on the changes, the Massachusetts Farm Bureau Federation said that it had heard that DOER thinks its changes allow for an expansion of solar on farmland. "We do not see this at all," the group wrote.

"It is our assessment, and that of many other stakeholders, that the proposed regulations would greatly decrease the areas of farm and forest land on which ground-based solar arrays could be placed. We do not know what is driving these proposed restrictions. From our perspective, they are short-sighted," Deputy Executive Director Brad Mitchell wrote.

On Monday, the Coalition for Community Solar Access released an analysis of the new SMART program regulations that found that the new rules would "effectively halt nearly 80 clean energy projects underway or planned for development" around the state.

"Millions of dollars and many years have already been invested in these clean energy projects around the state," Kelly Friend, a vice president at clean energy developer Nexamp, said in a statement. "Not only do these regulations effectively wipe out these investments -- but as important, many jobs and significant potential tax revenue to cities and towns, which are really struggling right now."

The coalition said that the two counties with the most projects at risk of being eliminated as a result of the new regulations are Plymouth and Bristol counties. In Plymouth County, 23 projects that total 107 megawatts are at risk, while Bristol County has 15 projects totaling 106 megawatts at risk.

Sen. Michael Rodrigues, who represents towns in both counties, wrote to DOER to say that he had heard a lot from constituents about the new land use restrictions. Those changes, Rodrigues said, give him "considerable pause" about the updated regulations.

"Stakeholders are concerned that these expanded land use protections will have an immediate impact on farmers, cranberry growers, and small communities. Currently, vast pieces of land owned by stakeholders -- with existing projects that have gone through the rigors of local permitting and NHESP review -- are mapped and designed as land within the purview of [Massachusetts Natural Heritage and Endangered Species Program]. These proposed projects under the existing emergency regulations are now in jeopardy," the Ways and Means Committee chairman wrote. "Additionally, the town of Rochester, which I represent and where some of these projects are proposed to be sited, stands to lose significant revenue benefits from the proposed rule changes. This is an issue and a great concern of mine."

A dozen more state lawmakers from Plymouth, Bristol and Barnstable counties sent their own letter to the DOER expressing their worry that "two key aspects of the proposed changes to the SMART regulations ... will negatively affect solar development throughout our region," specifically the land use changes.

"Farmers, including cranberry growers, of the Commonwealth are incredible stewards of our environment; they understand the balance of renewable energy and the maintenance of our wilderness. This regulation, however, effectively forces growers to choose between covering their cranberry bogs with ground mounted solar panels and give up millions of dollars in investment and thousands of man hours in creating the fragile bogs for growing or failing as a business," the lawmakers wrote. "The cranberry industry is already at the tipping point and the unintended consequences of the proposed regulations would eliminate a potential lifeline for many the cranberry harvesters in Massachusetts, while also negatively impacting many other agricultural businesses."

The letter was signed by Reps. Antonio Cabral, Claire Cronin, Dylan Fernandes, Carole Fiola, Susan Gifford, Patricia Haddad, Patrick Kearney, Christopher Markey, Norman Orrall, Elizabeth Poirier, Paul Schmid, and William Straus. The representatives suggested to DOER that projects already underway be grandfathered and allowed to proceed as planned.

"We need to protect projects and money invested in the Commonwealth and assure that those projects that have followed the rules to date and invested considerable resources are able to be realized without changing the rules mid-project," they wrote. They added, "The solar industry in Massachusetts has emerged as a national leader; however, we are concerned that the land use changes and failure to grandfather existing projects in the emergency regulations will actually represent a major step backwards, which would be very unfortunate."

The DOER official told the News Service on Tuesday that any solar project that is put into service within six months of the new regulations taking effect, essentially until mid-October, will not be affected by the land use policies in the updated regulations. The idea, the DOER official said, is to allow the projects that are furthest along in the permitting and development process to proceed as planned without creating an incentive for other projects to try to rush into service.

Sen. Mark Montigny from New Bedford also wrote to DOER to ask that the department "halt these proposed changes for further review."

The updated regulations were filed on an emergency basis in mid-April and took effect then. DOER has held a virtual public hearing on the update and is accepting public comment on guidelines related to the regulations through Monday. The regulations are slated to be officially promulgated July 15 and the DOER official said Tuesday that the department will make any changes it feels is necessary based on the feedback it has received.