PORT HURON, MI – A Michigan county’s pioneering efforts to restrict big solar farm and grid-scale battery projects with the state’s public health code have run into a legal roadblock.

A judge overturned St. Clair County Health Department rules that sought to address noise and “visual pollution” from projects, siding with the state’s largest power utility, DTE Electric Co., and other energy developers in lawsuits against the county.

Last July, some two months after the rules were put in place, DTE sued the county on the east side of Michigan’s Thumb. It argued the requirements amounted to new zoning regulations illegally masquerading as public health protections, and the justification for them wasn’t grounded in medical evidence.

Read more: Michigan county uses public health code to restrict solar farms, drawing DTE lawsuit

St. Clair County Circuit Court Judge Michael West granted a motion for summary disposition in favor of DTE on Monday, Feb. 2, court records show.

He did the same in favor of NorthStar Clean Energy, a subsidiary of Consumers Energy parent company CMS Energy, and another firm associated with a local solar project in a separate legal case. In that instance, St. Clair County had sued to enforce compliance with the rules.

The decision is an early defeat for efforts by the Republican-led county to influence requirements for large renewable energy installations after Democratic legislators passed a new state law in 2023 limiting how local communities can stand in the way of the projects.

St. Clair County leaders approved the public health rules in May 2025, finding the energy facilities pose “risks and dangers to public health.” They used local authority under Michigan’s Public Health Code, which is meant to control disease and address environmental hazards.

The regulations required large solar and battery projects to be completely screened from public view, mandated power inverters not emit “tonal noise,” required projects generally meet 45-decibel noise limits and forced developers to post $100,000 per megawatt bonds with the county for project decommissioning.

Projects would have to pay a $25,000 nonrefundable fee to apply for public approval.

St. Clair County Health Department officials said no applications under the regulations had been submitted. A webpage with the requirements was taken down Friday, Feb. 6.

Gary Fletcher, the attorney for St. Clair County, said the county board would likely discuss the litigation and the possibility of an appeal at its next meeting on Feb. 19.

In a statement, a DTE spokesperson said the outcome of the case “will benefit the community and DTE customers.”

“We will continue to prioritize working closely with potential host communities to responsibly site energy projects, following all local and state regulations that govern development. These projects bring significant benefits to communities including tax revenues that can support schools, first responders, roads and more,” the spokesperson said.

St. Clair County’s regulations, passed amid local pushback to several solar projects, were condemned by a Michigan arm of the Sierra Club, which said they were based on “flawed and misleading public health theories.”

A clean energy trade group, the Michigan Energy Innovation Business Council, also pushed back, saying the rules represented unachievable “poison pills” meant to doom projects.

In prior interviews with MLive and in legal filings, county representatives disputed those claims, saying the rules weren’t designed to kill projects but rather institute reasonable protections for residents.

The restrictions exceed standards in the 2023 state law that gives the largest renewable energy projects the option to go to the state for review if local rules are more restrictive than a set of minimum requirements — a pathway supporters say is necessary to meet state climate goals amid local project opposition.

So far across Michigan, four solar projects and one wind farm have applied for state approval, and none have completed the process.

Portside Solar, LLC, a company developing a solar project in St. Clair County that joined DTE’s lawsuit, alleged county leaders, frustrated with the changes in state law, passed the regulations “specifically targeting” its project to block construction.

In legal filings, the county denied the accusation, saying there was nothing in the state law preventing its application of the health code to the energy facilities.

It also went on the offensive, suing North Star and Lake Iris Solar, LLC in August 2025, alleging a solar project developed by the companies in Greenwood Townshipdidn’t comply with the rules and hadn’t gone through health department authorization.

Arguments over the legality of the county rules in that case and DTE’s case were consolidated and heard together, resulting in the rulings in the energy companies’ favor. Judge West will issue an order formally outlining the decision, according to the docket in each case.