PORTLAND, MAINE — About 600,000 so-called "smart meters" installed in homes and businesses by Central Maine Power pose no credible threat to health and safety, the state Supreme Court ruled Tuesday.

The Maine Supreme Judicial Court concluded that smart meter critics wanted an "impractically high" standard for safety and that the Maine Public Utilities Commission properly concluded that the public's health is not at risk from the smart meters in use across the state.

The approach of smart meter foes "would require an impractically high threshold for ensuring safety, and as a result would render nearly all utilities unsafe," Justice Andrew Mead wrote.

CMP spokeswoman Gail Rice said the utility is gratified by the finding that the smart meters are safe, but consumers will still have the option to opt out for a fee.

"From the program's beginning in 2010, we were very confident that the meters and related devices posed no credible threat to health and safety," she said.

Ed Friedman, a smart meter opponent who challenged regulators, said the court ignored independent testimony from international experts. "The court has miserably failed the people of Maine, instead relying on CMP supplied evidence," he said.

Smart meters transmit information to CMP's headquarters in Augusta using wireless technology similar to cellphones that emit radiofrequency radiation.


CMP contends smart meters hold the potential to help customers cut energy use while allowing the utility to quickly pinpoint problems during power outages. They also eliminate the need for meter readers, but CMP said the program resulted in no layoffs.

Critics contend smart meters cause symptoms including headache, fatigue, ringing in the ears and sleep loss among those with sensitivities to its signals.

The opponents said the PUC hadn't done enough to show smart meters were safe. They said commission's determination wasn't supported by enough scientific evidence and noted that two commissioners gave differing rationales for their decision.

But the state's highest court said the commission's decision was based on a "wealth of evidence" including more than 100 peer-reviewed scientific studies.

This was the second time smart meter opponents had gone to the state Supreme Court. The court previously ruled in 2012 that regulators failed to adequately address safety concerns.

The PUC went back to the drawing board and came to the same conclusion after a two-year process, noting that its decision is "based on the current state of science."

CMP contends that 99 percent of the smart meters currently installed send out a signal for 9 seconds or less each day, so any risk is minimal. Other devices that emit radiofrequency radiation include wireless routers, cordless phones and baby monitors.

About 7,000 CMP customers were opting out of the smart meter program, which requires a one-time fee of either $20 or $40 and monthly fees of $12 or $10.50, depending on the type of replacement meter that's installed, Rice said.