A company with Boulder ties is developing the largest solar farm east of the Rocky Mountains near Xcel Energy's Comanche Generating Station outside Pueblo.

The $200 million, 120-megawatt project will produce enough power for more than 31,000 homes when it comes online in summer 2016, said Eric Blank of Community Energy Solar.

Blank is co-partner of the company — which has its headquarters in Pennsylvania — and heads up the Boulder office, which oversees projects in the Midwest and West.

The project will more than double the 87 megawatts that Xcel gets from central solar plants and is part of 170 additional megawatts of solar generation that was approved by the Colorado Public Utilities Commission in December.

There are larger solar farms in California and Arizona, but none on this side of the Rockies.

The Comanche Solar project will consist of more than 450,000 mono-crystalline photovoltaic modules on a tracking system that will follow the sun from east to west, Blank said.

"This project is part of our vision begun in 2010 to bring utility scale solar at a competitive price to Front Range Colorado," Blank said in a news release.

In an interview, Blank said declines in photovoltaic costs from between $3 and $4 a watt a decade ago to around 70 cents a watt today made the project possible.

"In the solar space, it was not possible to do projects of this size," he said. "We have a multibillion wind industry in Colorado. We hope we're at an inflection point with solar where we'll also see solar take off in similar ways."

The solar farm will be located on 900 acres of grazing land near Xcel's Comanche power plant. Xcel spokesman Gabriel Romero said the location allows the company to take advantage of existing transmission capacity and save significant money by not building new transmission lines to connect a more remote solar farm.

The land is already pitched in a way favorable for positioning the solar panels, meaning the site will require minimal grading, Romero said.

"For the most part, it's perfectly situated for this," he said. "It comes in at very comparable price to coal and natural gas generation. It not only makes environmental sense, it also makes financial sense."

Until recently, Blank was a member of the Boulder-Xcel task force looking at possible alternatives to the city forming a municipal utility, but he resigned his position when the agreement with Xcel was close to being made public.

"I joined the task force to look for ways to bring Xcel and Boulder together, and I didn't want to become one more thing that people were fighting about," he said.

City officials had been aware that Blank was pursuing this project.

Boulder spokeswoman Sarah Huntley said Blank was a valuable member of the joint task force, and the city appreciates his contributions over the last year. However, the city believed it was appropriate for Blank to step down at this point, especially because the task force will be evaluating specific proposals from Xcel this spring.

Huntley said Boulder welcomes any renewable energy that Xcel adds to its generation portfolio, but the city continues to have concerns about how fully Xcel will use that power given its investments in coal.

Romero said the solar farm will produce power at peak demand times and will be used.

"This large-scale solar farm produces power at its peak when we need it the most, that late afternoon time frame," he said. "This will help us in many different ways."