Windsor plans to use floating solar panel system to power town’s public water facilities

Windsor is turning to alternative energy to power its water facilities, by teaming with a French company that will install floating solar panels this summer across a large pond on the town's public works property.

The solar power system is expected to reduce electric costs and push ahead the town's agenda to be a local leader in efforts to contend with climate change.

The floating 1.8-megawatt solar panels will supply the energy needs of Windsor's wastewater plant, public works building and Geyser pump station. The alternative energy system won't cost the town anything to install or operate because French enterprise Ciel and Terre is leasing the pond from Windsor for 25 years in exchange for producing discounted clean energy for use by the town's water operations.

“We are very excited about this because it is highly innovative and it is pretty amazing to have something like that in Windsor,” said Toni Bertolero, the town's public works director. “It shows that as a town we don't shy away from these things.”

Once the panels start generating electricity by the end of the year, it's estimated the solar system will produce about 90% of Windsor's water reclamation power requirements, and save the town about $175,000 a year on the Public Works Department's electric costs, or $4 million over the next 20 years, Sandi Potter, deputy director of water and environment management in Windsor, said in a statement. The town's water facilities' power consumption costs an estimated $650,000 annually.

Solar panels will be anchored to flotation devices - like those used to support docks at marinas - which will be tethered to the shore to hold the floating solar system in place, said Chris Bartle, business and development manager at the Ciel and Terre offices in Petaluma, where the company operates a U.S. branch. The panels will be placed over the water in a fixed position covering about 4 acres of a nearly 18-acre pond.

“Extra energy not being used will be stored in the grid to be tapped for months where there is less light and during nighttime hours,” said Bartle, noting the Windsor energy system will be the company's seventh installed in the United States.

For Windsor's leaders, the floating solar system represents one of many steps they are taking toward achieving their climate goals.

“We are taking a hard look at our greenhouse gas emissions, and solar is something we have been wanting for a while,” Bertolero said. “We are also replacing our gas-powered vehicles (with) electric, looking at renewable fuel and installing LED streetlights.”

Ciel and Terre will build and install the floating solar system and is “paying for everything, which was the beauty of the whole arrangement,” Bertolero said.

Windsor officials discovered the solar power opportunity through the Sonoma County Water Agency that for years has been trying to lease a few of its ponds to floating solar system technology enterprises. The water agency learned that the French firm also was looking to collaborate on a project here.

Windsor's Public Works Department was recommended and now it's becoming a reality, said Dale Roberts, principal engineer for the water agency.

“They are the first government department in the area to successfully team up with a floating solar panel project company, so we are really happy for them,” Roberts said of Windsor's Public Works Department officials.

A handful of wineries in the North Bay have smaller versions of the floating solar system, including Far Niente Winery in Napa Valley, but Bartle said Windsor's will be the largest in California. A similar solar device in New Jersey built by Ciel and Terre is said to be the largest in the U.S.

Healdsburg officials also are talking to multiple companies about the possibility of a floating solar system project. Bartle said Ciel and Terre officials haven't yet decided whether to make a solar project pitch to Healdsburg.

The company, founded in 2006, has eight offices around the world, including its U.S. headquarters in Petaluma. The office opened three years ago to target the wine industry, since most vineyard owners look for innovative ways to go solar without compromising their land, Bartle said.

“Setting up an office here made sense because we are so close to the heart of Wine Country,” he said.

The most popular market for the floating solar project is in Asia, where countries including Taiwan and Japan have little to no land left but are surrounded by water, he said.

Although the floating solar trend has yet to catch on in the U.S., Bartle said he is in talks with government leaders in at least 20 different states, including other cities in Sonoma County, about potentially launching solar projects.

Despite unpredictable weather patterns in the North Bay, Bartle said it is a great location for solar projects.

“They (the panels) operate in fog and even with a little frost, since they do not turn on and off,” he said. “The panels can still be effective even during the most overcast days.”

You can reach Staff Writer Alexandria Bordas at 707-521-5337 or On Twitter @CrossingBordas.

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