Lawmakers voted to reauthorize Connecticut’s rooftop solar incentives until 2035 on Wednesday, avoiding a potential Republican filibuster that threatened to run out the clock on a key priority for many Democrats, solar developers and climate activists.

The legislation, House Bill 5340, passed the Senate on a mostly party-line vote shortly before 8 p.m., just hours before the midnight deadline marking the end of the legislative session. The bill passed the House earlier in the week, and now heads to Gov. Ned Lamont’s desk for his signature.

“This bill is another step in the right direction and builds on the success of our current programs while maintaining our dedication to lowering the cost of these programs for our ratepayers,” said Sen. Norm Needleman, D-Essex, chair of the legislature’s Energy and Technology Committee.

In addition to re-authorizing the state’s exsiting residential, commercial and community solar programs, the bill places those programs under a target budget of $85 million a year, which advocates say represents a nearly 10% savings over the programs’ historic cost. Solar installations that are paired with battery storage would be exempt from the budget.

The bill also includes other provisions setting up regulations for the adoption of plug-in solar panels, expediting solar permitting and imposing a one-year moratorium on new approvals for large solar arrays in the towns of East Windsor and Enfield, which are home to the highest concentration of solar in the state.

But most of the focus from critics has been on the expense of subsidizing the development of rooftop solar in Connecticut.

The state’s existing rooftop and community solar programs cost a combined $118 million in 2025, according to the Public Utilities Regulatory Authority. Those costs are passed along to customers through the public benefits charge. (Needleman said that last year’s costs were inflated by people rushing to build rooftop solar systems before the expiration of federal tax credits on Dec. 31).

Opposition to the bill in the Senate was led by Sen. Ryan Fazio, R-Greenwich, a ranking Republican on the Energy and Technology Committee who is also seeking the GOP nomination for governor.

Fazio introduced several unsuccessul amendments to the bill, including one to eliminate the public benefits charge and shift the costs of its programs onto the state’s budget.

“We all know, we all feel that electricity rates are far too high in the state of Connecticut,” Fazio said. “It’s not as if it has to be this way, but rather the policies and the decisions made in this State Capitol have contributed to these high rates, making Connecticut far less affordable than it needs to be.”

The bill also became subject to attempts at horse trading between the House and Senate, when an amendment appeared earlier in the week on an unrelated bill proposing tougher safety regulations on battery storage systems. That legislation, H.B. 4572, also faced a time crunch for passage as the session entered its final two days.

Senate Minority Leader Stephen Harding, R-Brookfield, said Tuesday that he was trying to get the House to act on the battery measure as part of negotiations over the movement of several other bills, including the reauthorization of the rooftop solar incentives. Harding represents the town of New Milford, where local opposition has sprung up against a proposed 140-megawatt battery storage facility.

“It’s part of negotiations with other energy bills. I’m working to try to get it upstairs because it’s a priority for me,” Harding told the Connecticut Mirror.

But advocates of solar and battery storage projects argued that the proposed safety standards were so restrictive they would effectively ban people from purchasing batteries for their homes and businesses.

“No batteries are actually certified to [the standard],” said Kyle Wallace, a lobbyist for the battery and solar developer Sunrun. “If this amendment were to pass, as of Jan. 1, 2027 there would be no ability to do residential batteries in the state.”

By Wednesday morning, support for the battery amendement had fizzled in the House and a second, less restrictive amendment was put forward authorizing the Department of Energy and Environmental protection to conduct an environmental assessment on large battery projects. The underlying bill was still waiting for a vote in both chambers around 9 p.m.

Meanwhile, Senate Republicans — exhausted after their all-night debate in the upper chamber — reached an agreement with Democrats to limit debate Wednesday evening on the solar bill and a few other legislative priorities so everyone could get a few hours of rest, according to state Sen. Rob Sampson, R-Wolcott.

“In order for us to even be able to go home and take a shower, our leadership had to agree to this,” Sampson said.

The debate on the solar bill lasted about two hours in the Senate.

Afterwards, advocates for the legislation celebrated in the Capitol, saying the bill avoided an additional blow to an industry that has suffered under the the shift in federal policy toward renewable energy under President Donald Trump’s administration.

“It wasn’t a perfect bill by any stretch, we were disappointed by, for instance, the new caps on the amount of rooftop solar that can be built, and the moratorium language on certain solar farms,” said Christopher Phelps, the state director of the non-profit advocacy group Environment Connecticut.

“But on the balance, it ensures that we can continue to go solar in Connecticut, whether you’re a family or a business… and that’s a good thing,” he added.