Electricity from 40 acres of solar panels could light the homes and businesses of an eco-friendly development planned in Arden Hills.

The Ramsey County Board on Tuesday voted to purchase land at the former Twin Cities Army Ammunition Plant (TCAAP) site for what would be the largest solar array in the metro area.

Xcel Energy would manage the solar installation, which is expected to generate enough energy to power every building in the planned Rice Creek Commons development and then some, officials said.

"We're very cognizant of how do we make it unique? How do we really make it stand out?" Commissioner Blake Huffman said of the proposed development. The solar component, which could generate up to 12 megawatts, adds a "wow factor," he said.

Ramsey County bought and cleaned up hundreds of acres of the TCAAP site to make way for Rice Creek Commons, a mixed-use community to be developed by Minneapolis-based Alatus LLC.

However, officials acknowledged that they face numerous hurdles to make the solar-powered community a reality.

What's more, they are up against a deadline: The solar panels must be in place by the end of 2019 to qualify for a 30 percent tax credit on installation costs. Deputy County Manager Heather Worthington said the panels should go up in 2018.

And before installation can begin, the Minnesota Public Utilities Commission must approve the solar project, Arden Hills needs to agree to the land use, and Ramsey County must buy the land and finalize a development agreement with Xcel.

The U.S. General Services Administration owns the land, part of the old TCAAP site, and has agreed to sell 62 acres to the county for $1. Worthington said she hopes to wrap up the deal by the end of the year.

The county would use 40 of those acres for the solar array and sell the rest to the state, which proposes to build a new State Emergency Operations Center for the Department of Public Safety there.

While the actual purchase of the 62 acres would cost next to nothing, the county would have to demolish buildings on the site to prepare it for solar panels at an estimated cost of $1.25 million, according to county documents.

The county then would lease the 40 acres to Xcel Energy. Over the term of the lease — which has not yet been decided, but likely would last more than 20 years — the county would recoup the $1.25 million in demolition costs through lease payments, Worthington said.

"We have an agreement in place to work on developing this solar facility, but there is no financial commitment at this time," said Laura McCarten, a regional vice president at Xcel Energy.

Ramsey County eventually plans to turn Rice Creek Commons over to the private market, Huffman said. He added that solar panels would help the county make money off the property in the long run.

"The market is strong for this housing that is also environmentally sensitive," Huffman said. "We are confident that this is going to help us get our overall investment back."

As the solar plan moves forward, so does the overall development of Rice Creek Commons.

Arden Hills and Ramsey County recently selected Alatus, the company that redid Block E in downtown Minneapolis, to develop the community. It must follow Arden Hills' master plan for the site, which includes a town center surrounded by a mix of commercial and residential neighborhoods laced with parks and trails.

The city's and the county's vision for the community includes solar power as just one piece of the effort to make Rice Creek Commons environmentally friendly and sustainable. They hope to see efficient buildings, clean energy businesses and other green initiatives emerge as the site is developed.