IN THE BATTLE to lower stubbornly-high energy costs for struggling residents, Massachusetts regulators adopted a proposal with buy-in from the energy industry, advocates, and state officials that would wipe away a steep barrier that has squeezed the uptake of solar power.

The move – which would dramatically reduce solar connection costs for some homeowners and will take effect this fall – was finalized this week by the Department of Public Utilities. It could save thousands of electric customers looking to install solar panels across the state from being saddled with last-minute, seemingly random charges that could stretch past $10,000 per project.

“We knew we needed to do something about this,” Staci Rubin, a DPU commissioner, said in an interview. “This is an outcome that everybody is going to be supportive of. That’s rare at the DPU.”

The change is a small win for Gov. Maura Healey’s push to streamline new projects, especially for solar, as part of an “all of the above” approach to energy. It comes at a time when electricity prices in the state are reaching double the national average, power demand is rising, and deadlines for climate commitments are creeping closer. Massachusetts had already been falling behind on new solar installations and a goal to deploy 10 gigawatts of solar by 2028 even before Republicans in Washington eliminated federal incentives for the clean energy source.

When a resident attempts to add solar to their home, one of the last steps in the wonky process to connect the project to the grid, known as interconnection, is for the utility to determine whether the transformer serving that home can handle the electrical output the home will now be sending back to the grid. A key part of the financial puzzle for a resident to add solar is the ability to sell excess power generated to reduce their electric bill.

But if the utility determines the transformer can’t handle that influx of power, it needs to upgrade that infrastructure — costs that average thousands of dollars and currently fall on the sole homeowner responsible for triggering that upgrade, even if that transformer serves multiple homes and businesses, like many do.

That turns the system into a game of chance based on when you happen to get in line: If one neighbor adds solar and eats into the available capacity but doesn’t trigger the upgrade, the next unlucky home to add solar may push the transformer past its limit and get penalized just for going second. Once that homeowner pays for the upgrade, the third homeowner that adds solar will reap the benefits of the new transformer’s expanded capacity without paying for the costs.

The homeowner often doesn’t know whether or not they will trigger the pricey upgrade until the project is in the permitting process and financing and construction work have been secured.

That’s exactly what happened to Abe Walters, a homeowner in an environmental justice community in Bellingham who CommonWealth Beacon spotlighted earlier this year. Walters had already secured a loan from the Massachusetts Community Climate Bank, selected an installer after receiving a slew of estimates, and navigated ever-changing tax credits to make his project pencil out through lower utility bills only to then be hit with a transformer upgrade cost of $12,000 — muddying the financial viability of his project.

The DPU’s approval of the new system eliminates that risk, instead requiring each homeowner looking to install a residential solar project or battery storage to pay a $225 fee to their utility. That fee would more equitably share those upgrade costs that all customers benefit from, covering up to $10,000 of any necessary infrastructure costs for connecting solar to the grid for Eversource and National Grid customers and up to $1,450 for Unitil customers.

Most other states have a system much like Massachusetts’s current one, but Minnesota, Maine, and Connecticut have adopted solutions similar to the one the DPU just greenlit.

“People who are eager to help participate and contribute to the clean energy transition can do so without these major cost barriers on the interconnection side,” Rubin said. “When we have more people with solar facilities and more solar on the system, that’s increased supply, and that’s going to drive down costs for all distribution customers.”

Though only roughly 3 percent of Bay State residents adding small solar projects are hit with the unexpected sticker shock for upgrading transformers, forcing them to either pay the steep price tag, downsize their projects to avoid triggering the upgrade, or cancel them outright, the DPU’s move is being seen as one to bolster project certainty.

“We joke in the sales team that we get so much practice because we get to sell a project five times,” said James Manzer, regional vice president of the solar company ReVision Energy who led the part of the larger DPU working group focused on this new cost-share plan. “You sell the initial time, and then permitting comes back. You’ve got to resell because maybe you had to change something. And then you have to resell it when interconnection comes back. And you may need to tell the customer, ‘Oh hey, by the way, we need to upgrade your transformer, and that’s $7,500 extra. This is your new return on investment.’ For us, it’s waiting with bated breath to move a project forward, and it’s really clunky and really frustrating for a customer.”

Plus, the relatively small percentage of customers needing to pay for grid upgrades doesn’t fully capture the scope of the problem. Data from Eversource and National Grid show that many communities across Massachusetts are already at or nearing grid capacity, meaning that the next interconnection request could trigger transformer upgrades that under the current model could stifle solar projects.

It’s not entirely clear what the DPU’s move will mean for residents who have already been notified that their proposed solar project will trigger a transformer upgrade. Walters, the Bellingham man, said that he is still assessing what the new policy will mean for his project, which has now been in limbo for five months since he was told about the sudden $12,000 cost.

Members of the working group that pitched the new cost-share mechanism that the DPU accepted are praising it as a new standard for how to quickly gain consensus among a diverse set of stakeholders who may not always agree.

The concept, once the group started work on it last summer, took about a year to come to fruition. The plan was submitted to state regulators in March.

Brendan Moss, a spokesperson for National Grid, said in a statement that the new system will “create a more predictable, transparent, and equitable path to interconnection.” Olessa Stepanova, a spokesperson for Eversource, hailed the “collaboration” that led to agreement on the new approach.

The utilities worked in good faith to reach agreement, said Kate Tohme, director of interconnection for Massachusetts-based solar developer New Leaf Energy and co-chair of the DPU working group. Connecting more residential solar projects also helps them reach their own state-mandated clean energy targets as fewer customers back out of projects over the upgrade costs.

“We know that we aren’t going to always come to 100 percent consensus on every issue, and it’s not always easy,” Tohme said. “But this should be the goal and the model for groups across the country. We’re not submitting reports. We are, through a defined process, putting solutions before the DPU and achieving an outcome.”