Investors behind 111 solar energy farms in Maine filed a lawsuit on Monday against the state over a law that will place new fees and restrictions on commercial solar developments at the start of 2026.
The lawsuit, filed in federal court in the District of Maine, claims that the state encouraged new solar power developments to meet its climate goals starting in 2018 when it adopted net energy billing, but has now changed the terms after the developers have made their investments and “cannot respond to Maine’s reversal by taking their [solar farms] elsewhere.”
“When a state retroactively changes the rules on projects already operating and serving customers, it tells investors, lenders, and developers that the state cannot be trusted to provide a reliable, rational business climate for future investment,” said Jeff Cramer, president and CEO of the Coalition for Community Solar Access, a national trade association, in a press release announcing the lawsuit.
The 111 plaintiffs are subsidiaries of 11 investors that own solar farms in Maine: Altus Power, Catalyze Holdings, CleanCapital Holdings, EDPR NA Distributed Generation, Luminace Holdings, Nautilus US Power Holdco, Nexamp, Renewable Energy Alternatives, REA Investments, Summit Ridge Energy, and Syncarpha Capital
They use net energy billing to effectively sell the electricity they generate through a credit system.
In the lawsuit, which names the Maine Public Utilities Commission and three of its members as defendants, the developers credit net energy billing with transforming Maine’s solar power generation from “a rounding error on the state’s electricity supply” to powering more than 340,000 homes today, which entailed $1 billion in investments from the developers.
But changes under LD 1777, which was signed into law in June and enacts its first major changes at the start of 2026, violate the developers’ constitutional protections for contracts and property, the lawsuit says.
LD 1777’s sponsor, Rep. Sophie Warren, D-Scarborough, testifying in May, called net energy billing “a program that has achieved much, but that now needs recalibration.”
Net energy billing is tied to the standard offer rate, which was fine when it was enacted, Warren said, but unexpected volatility in the market since then has “translated into unexpectedly high returns” for solar farm developers, “placing an unnecessary burden on nonparticipating ratepayers.”
The bill “closes loopholes that have allowed windfall profits to accrue at public expense,” Warren said.
At the start of 2026, the law will effectively block any new commercial developments that use net energy billing — sometimes called “community solar” — such as the ones operated by the plaintiffs, from being built, by barring their ability to make contracts with electricity distributors, like Central Maine Power and Versant Power.
Additionally it will enact a tiered system of tariffs for commercial solar farms rated to generate more than 1 megawatt, with a higher rate for those between 3 and 5 megawatts.
The additional charges would cost the solar farm owners $2,800 a month for a 1 megawatt facility and $30,000 per month for 5 megawatts, according to the developers’ lawsuit.
Most solar farms in Maine are rated for 5 megawatts or less.
The new law does not apply to residential customers who use net energy billing, such as homeowners who offset their electric bill by using solar panels that are tied to the grid.
