A Colorado solar-energy innovator. That describes Walden, a town of about 600 people at an elevation of nearly 8,100 feet and with an average annual high temperature of just over 51 degrees Fahrenheit.

It’s not the first place you would expect to break new ground when it comes to renewable energy. But it’s what the town decided to do on water, not the ground, that makes it a trend-setter. Walden is the only Colorado community with a floating solar array and one of just a handful nationally.

Now, the Colorado Energy Office is looking around the state to see if other bodies of water would make good solar energy sites. Walden town officials and the companies and consultants behind the project are getting frequent calls from others interested in their own floating arrays of photovoltaic panels.

The project was named the 2019 commercial/industrial project of the year by the Colorado Solar and Storage Association.

“We looked at wind power, given how windy it is up here,” Walden Mayor Jim Dustin said.

But town officials had concerns about the costs of operating and maintaining a wind farm. Town officials then considered a floating solar array, which Dustin said Johnson Controls first suggested. The company was working with the town to figure out ways to be more energy efficient.

“When we got done talking about it, it seemed like a good idea. It seemed financially feasible,” Dustin said. “I didn’t know it was so innovative.”

And so far, the 208-panel array is proving to be hardy as well. Since coming online in October 2018 to power the town’s water treatment plant, the array installed on a nearby pond has endured the area’s snow, which averages about 63 inches annually, and frigid temperatures, which can plummet to 30 below zero or lower. Walden is in North Park, a high-elevation basin in northwestern Colorado bordered by mountain ranges.

“It survived its first winter,” said Mark Russell, Walden’s public works supervisor.

There were days when snow covered the panels and production of electricity was zero. At one point, part of the rack that holds the panels afloat submerged when the water froze. The floating platform is anchored to the banks.

“After everything worked its way to the surface, then we had electricity,” Russell said.

Town employees tried shoveling the snow off the panels, but it was labor intensive, Russell said. Most of the time, the dark edges of the panels get enough sun to start melting the snow. Johnson Controls factored in lost production because of snow when calculating the costs and savings, Russell added.

Although production was low in January, February and March, the solar-generated power started shooting up in April. The town is able to sell its excess power to Mountain Parks Electric, the power association that serves the area, and draw on the grid when it needs to.

Rowena Adams of Johnson Controls expects the array, which can produce up to 75 kilowatt hours of energy, to provide half of the power for the water treatment plant annually.

Adams and town officials decided to go with an array on the treatment plant’s retention pond because the town didn’t have any land available, and the plant’s roof wasn’t a good option. France-based Ciel & Terre, which designs and builds floating solar energy systems, worked on the Walden project, one of seven it has completed in the U.S. and one of 155 of its installations worldwide.

The Walden array is in the coldest spot worldwide so far, Chris Bartle with Ciel & Terre USA said in an email.

The company’s solar systems in South Korea and Sweden might get more snow, he added.

While the solar array survived the winter, people are waiting see how the numbers — production of electricity and costs — shake out the first year. The town is covering half of the $400,000 price tag. A $200,000 grant from the Colorado Department of Local Affairs is covering the other half.

“The irony of that is that money came from oil and gas severance taxes,” Dustin said of the state funds.

The state funnels some of the severance tax revenue to communities to address the impacts of oil and gas development. Drilling is on the rise in North Park, which sits atop part of the Niobrara oil shale formation.

Mountain Parks Electric contributed $8,000, which the town will use to pay for consulting services, Dustin said. The nonprofit GRID alternatives installed the system. And the Colorado Energy Office is providing technical support.

Jackson County resident Barbara Vasquez heads a council that advises Mountain Parks on renewable energy. She called the town’s floating array and a solar system being built by Mountain Parks north of Walden “marvelous milestones” for the area.

“And it’s driven, particularly the one-megawatt array by Mountain Parks, by economics,” Vasquez said. “So you don’t have to be on the liberal or green side of any issue to see the dollars and cents logic of going with wind and solar.”

Dustin, Walden’s mayor, said it’s a close call for him on the economics so far. The savings aren’t yet meeting his expectations of $10,000 a year.

However, Mountain Parks general manager Mark Johnston was confident the city would see savings. “My guess is by the end of the year, it somewhat evens out.”

Johnson Controls calculated that the array will pay for itself in 20 years.

Carl Trick, a member of Mountain Parks board of directors, isn’t as optimistic.

“I don’t think it will pay for itself. You drive by here in the winter time and the thing’s covered with snow,” Trick said. “Solar is great in my mind, but at this latitude, solar is about 20% effective.”

The array that Mountain Parks is having installed on about five acres of land north of Walden will automatically tilt to shed any built-up snow.

The town has a lease-to-buy option on nearby land if it decides a ground-mounted array would work better. But so far this summer, the solar array has been highly productive. Johnston said from June 1 to July 1, it produced 9,024 kilowatt hours of energy, or about 75% of the electricity the plant used.

There are other benefits. Walter Sharp, who worked on the design and feasibility study for the Walden project, is among those who see putting solar arrays on water as a good way to reduce evaporation from reservoirs and lakes. Other environmental benefits promoted by enthusiasts include the water’s cooling effects on the panels and reduction of algae growth because there’s less sunlight to feed the plants.

And the fish should be all right with floating arrays, Taylor Lewis of the Colorado Energy Office said. In fact, the panels might provide shade and cooler temperatures for trout, which have struggled as climate change has heated up lakes and rivers.

Lewis, a senior program engineer, said he was working on water conservation and energy efficiency issues when he heard about Walden’s solar array. Arrays on water bodies have been credited with cutting the rate of evaporation, and in Colorado’s high altitude and warm, dry climate that could be a huge benefit.

Some estimates put the annual loss through evaporation at anywhere from 12 to 90 inches per water body, Lewis said. Floating arrays might be a way, he said, to “not only generate power and generate it more efficiently because of the cooling effect but also keep some of the water in the ponds, reservoirs and lakes that we and people downstream of Colorado rely on.”

Researchers at the National Renewable Energy Laboratory in Golden estimate that placing floating solar arrays on the country’s roughly 24,000 man-made reservoirs could make up about 10 percent of the U.S. annual electricity production

In some cases, installing a solar array on an otherwise unused body of water might be less of a challenge than finding available land, Lewis added. The Colorado Energy Office is writing a study to assess other possible sites around the state, look at the various issues and chronicle the process Walden went through. He said the study will likely be completed by the end of the year.