MARS HILL – Nearly three months after starting up commercial operations, the Mars Hill Wind Farm is churning out loads of green energy.

Since March 27, the $85 million wind farm atop Mars Hill Mountain – New England’s first utility-scale wind project – has generated more than 25,000 megawatt-hours of electricity, or enough to supply 15,000 New England homes, according to an official with UPC Wind Management, LLC.

A power company that relies on fossil fuels would need 50,000 barrels of oil or 13,500 tons of coal to create that much power, according to company estimates.

“The fact that we were able to achieve our projected level of operations in the first three months is an indication that not only were we accurate in our assessment of the wind resource at Mars Hill and the capability of the machines, but that Maine is a place where commercial energy is viable,” Michael Alvarez, UPC executive vice president and chief operating officer, said on Tuesday. “We’re pleased with the performance of the plant to date.”

While UPC officials are upbeat about the wind farm’s progress, they still are working out a few issues.

In recent months, there have been worries about access to recreational trails on Mars Hill Mountain. Alvarez said that, despite word to the contrary, there is ATV and hiking trail access on the mountain right now. He added that UPC is working with officials from the International Appalachian Trail and the Big 13 ATV Club of Mars Hill to open up for recreational use some of the newly developed roadway on the mountain, which connects the 28 wind turbine sites.

Alvarez explained that the process involves working with the landowners that gave the company easements to locate turbines on their properties, and making sure safety issues are addressed. He said while officials hope to help make as much of the road as possible available for recreational use, access will be limited near generating equipment.

Since December, there also have been concerns about sound levels. On June 21, UPC filed its sound-level study with the Department of Environmental Protection. The company hired a consultant to complete the study following several noise complaints made to the DEP. The study, which measured both ambient sounds and the sound from wind farm operations, was conducted over the course of 96 hours in May at nine sites around the mountain.

Wind farm operation sound levels in the study ranged from 30 to 52 decibels, depending on how hard and which way the wind was blowing and at what percentage the turbines were operating. The study showed that turbine sounds rose in relation to ambient sound, so whenever turbines were more perceptible, they were in direct correlation with natural sounds.

The study also found that sound levels during moderate to full operation ranged from 8 decibels below to 4 above estimates made in 2003. Those estimates – which were included in UPC’s site location permit application to the DEP – indicated that sound levels at several homes around the mountain had the potential to meet or exceed state limits.

In protected residential locations, the DEP states sounds cannot exceed 60 decibels during the day and 50 at night, which is the equivalent of songbirds trilling. In quiet areas, where daytime sounds stay below 45 decibels, the number drops to 55 decibels during the day and 45 at night.

Alvarez confirmed that estimates showed there would be sounds above 45 and 50 decibels at some spots around the mountain. But he added that the DEP granted the permit with a variance that allows UPC to operate the turbines at those sound levels.

The DEP gave the variance because its site rules were based on wind speeds half as strong as what Mars Hill gets; and the stronger the wind, the louder the sound is going to be. Because the sound estimates were only slightly over limits in some places, the DEP determined in granting the permit that the “project will not have an unreasonable adverse impact on protected locations.”

What concerns residents around the mountain is the possibility that nothing will be done about the noises that come and go. Some have described it as sneakers in a dryer or like the heartbeat of a baby in the womb; several residents have complained of sleep disruption, headaches, and loss of peace and quiet. A local DEP official has visited the mountain many times and said he has heard the sounds residents are talking about. Nick Archer, northern Maine regional director, described it as a “whooping sound that was noticeable.”

Wendy Todd, a member of the Mountain Landowners Association – a group of 18 families that has concerns about the wind farm – said homeowners are hoping to meet with the DEP to get their questions answered before a determination on the sound-level study is made.

“Our understanding is that if they’re over [limits] at all, they’re out of compliance,” Todd said on Monday. “We’re concerned about the way UPC chose to word their statement … and we’re relying on the DEP to protect us from a company that tends to want to make light of the issues. Someone reading this [study] would think that there’s no issue of noise and the people who are complaining are just complainers.”

Alvarez said officials take very seriously the impact the wind farm has on the community.

“We are extremely interested in the community reception and are actively engaged in trying to respond to concerns that are raised by members of the community,” he said.

In the sound-level study, UPC proposed three additional rounds of voluntary sound monitoring – to be done this August and November and in February 2008. UPC also proposed working with turbine manufacturer GE to evaluate the potential for the “reasonable reduction of operating sound levels without adversely affecting wind farm operating performance.”

Nick Archer said on Monday that the department will review the sound-level study in the next few weeks and expects to make a determination in July as to whether UPC is in compliance, in noncompliance, or whether “some work needs to be done.”