The Legislature's failure to raise net-metering caps on solar power could stymie several Berkshire projects and thwart a significant reduction in local utility customers' electric bills.

Solar advocates are urging the House and Senate to reach a legislative deal soon to increase net-metering limits so solar projects can take advantage of federal tax incentives before they are reduced or eliminated at the end of 2016.

Net metering, a billing mechanism, credits solar energy system owners for the electricity they add to the grid. It's an essential part of the financial formula that promotes the development and use of solar-generated power.

Stockbridge is among several communities seeking to build a solar array on closed landfills and other municipal property, but the cap stands in the way.

"There is a lot of support in Stockbridge for this, and hopefully the Legislature will lift the cap," said Charles Gillett, chairman of the town Select Board.

On Monday, Stockbridge Selectmen unanimously agreed to hire Ameresco, a green energy company, to install the solar panels, which gives the Framingham firm a year to get it operational before the tax credit reduction takes effect Jan. 1, 2017.

Selectmen Stephen Shatz said Ameresco would supply the electricity based on a complicated pricing formula that "will provide a substantial amount of money for the town over the next 20 years."

While lawmakers wrapped up the formal fall session Nov. 19 without passing net-metering legislation, state Sen. Benjamin Downing of Pittsfield holds out hope that a compromise between a Senate bill and a more strings-attached House version can be hammered out and voted on in informal session — possibly by the end of the year.

"We have had informal conversations and I'm hopeful, but not clear how we get there," he said.

The state's net-metering program allows solar-producing businesses and municipalities to sell that energy back to the grid at retail rates. The current caps — 4 percent on private installations and 5 percent on public — are calculated as a percentage of the peak electrical usage.

But net-metering caps have been for the territory served by National Grid, which includes Stockbridge, Williamstown, most of Lenox, and 14 other Berkshire cities and towns. Any proposed projects in those communities wouldn't be permitted to move forward unless the caps are lifted.

Williamstown has both a town solar project and a private residential solar garden in the works, with Lenox pursuing installation of municipal solar panels on the town's capped landfill.

"Siting solar on a landfill is a no-brainer as the [open space] is just sitting there," said Lenox Selectmen Ken Fowler. "It has very little impact on the environment compared to [wind] turbines."

In addition, Lenox and Lee are collaborating on a joint solar project at a former paper mill landfill on Willow Hills Road in Lee, while Pittsfield should break ground next spring on a solar array at its closed city landfill at the end of Downing Industrial Park.

Those projects aren't in jeopardy. Pittsfield, Lee and the 13 remaining Berkshire towns are served by Eversource, which has yet to reach its net-metering cap.

Nevertheless, projects in the queue must be built, fully operational and connected to the grid to take advantage of the federal tax breaks before Jan. 1, 2017, when the commercial incentives on solar array construction drop from 30 percent to 10 percent and the residential ones are eliminated, said Beth Greenblatt, solar energy consultant for Pittsfield, Lee, Lenox, Stockbridge and Williamstown.

"The solar industry tells me they are fully confident the tax relief will be extended for those already under construction," Greenblatt said. "It will likely only grandfather those already under the [state] cap."

The five Berkshire municipalities for which Greenblatt consults are eager to get their projects built, powering their public buildings with less expensive electricity.

Pittsfield's planned 2.9-megawatt solar array is expected to generate 3.8 million kilowatt-hours of electricity at a projected cost of $7.53 per kilowatt — about half the going rate from Eversource.

"The city is eager to see this solar array go online as it will provide real cost savings to the city while furthering our goal of becoming a truly sustainable community," said James McGrath, Pittsfield's parks and open space manager.

Over the summer, North Adams flipped the switch on its 3.56-megawatt solar power installation, and coupled with solar produced electricity bought from two arrays to the east, will save property taxpayers more than $300,000 annually on its municipal electric bills, according to city officials.

Dozens of North Berkshire private property owners pursuing a communal solar array also want the Legislature to see the light and raise the net-metering cap. Pittsfield-based Center for EcoTechnology (CET) and the Williamstown COOL Committee, a citizen-driven alternative energy group, have teamed up to identify two sites in Williamstown and one in North Adams that could serve as solar gardens. The solar arrays would produce electricity for dozens of homeowners who can't have solar panels installed on their roofs or in their yards.

CET Associate Director Nancy Nylen, a COOL member, said the collaboration is moving forward at least on the two Williamstown sites.

"We're proceeding to evaluate the sites and form a LLC [limited liability company] that we need to do the project," she said. "We are not forming it to make a profit."

Solar advocates find Berkshire municipalities, home and business owners are still interested in solar arrays to control the cost and origin of their electricity.

"One reason we do [solar] is to connect people with their energy source and we're doing that," Nylen said.

Contact Dick Lindsay at 413 496-6233.