HIGHLAND PLANTATION – When the developer of a wind farm here said at the end of December it would scale back its project from 48 to 39 turbines, it estimated that energy production would drop by 25 percent.

Now the developer, Brunswick- based Independence Wind, says reducing the number of turbines by 19 percent, while switching to different models, means the energy decrease actually will be closer to 10 percent.

The revised application, which is pending review by the Land Use Regulation Commission, states eight turbines are now barred from Stewart Mountain — the windiest location, but also the area closest to Bigelow Preserve.

Removing eight turbines from Stewart Mountain “eliminates almost 25 percent of the estimated energy production from the project and is a significant financial concession,” Rob Gardiner said in a statement Dec. 28.

Gardiner, a former Maine Public Broadcasting Corp. president, is a principal at Independence Wind with former Maine governor Angus King.

However, the company will not lose 25 percent of its estimated electricity output by reducing the number of turbines. The number is between 3 and 15 percent.

The proposed wind farm’s total production is projected at 306,000 to 350,000 million kilowatt hours of electricity per year, according to the newest documents filed with the state commission. The original number was 360,000 million kilowatt hours per year, according to the developer’s first application.

So where did the 25 percent estimation come from?

When the developer dropped the Stewart Mountain site, it also changed the type of turbines proposed for its remaining sites, Gardiner said.

The new types of turbines, one of which was recently put on the market, are a better fit for the amount of wind at the proposed sites and will produce more electricity than previously-planned turbines.

If the developer had retained the old turbines, and reduced the quantity, the loss in energy production would have represented a 25 percent decrease, Gardiner said. But with the change in turbine-type, the loss isn’t as great as originally expected.

“We’re taking 39 turbine locations and putting in machines that may be more suited to the location in terms of converting potential wind energy into actual electricity. So our total output hasn’t really dropped that much,” Gardiner said. “The remaining 39 turbine spots can generate more power than the plan for those same turbines in the first application.”

The developer is now eyeing the GE 2.5 and the Siemens 2.3 and 3.0 megawatt turbines, Gardiner said. It had previously looked at the Vestas 3.0 and others.

The Siemens 3.0 machine — which is designed to work in less windy locations with a higher efficiency — was not on the market when Independence Wind made its first application in January 2010.

Morning Sentinel Writer Erin Rhoda can be contacted at 474-9534 or at:

erhoda@centralmaine.com