In a sandy field outside Eau Claire, in western Wisconsin, a new crop is sprouting: solar power.

The Eau Claire Energy Co-Op, a member-owned rural co-op with 11,000 customers, is installing the largest utility-owned solar power system in the state, with 2,816 panels capable of delivering 875 kilowatts of DC power.

The first section of the system, built by Able Energy of River Falls, Wisconsin, was energized on October 1.

The co-op’s Member Solar program offers shares of the system to member-customers at cost -- only $650 per panel, or $2.10 per watt.

The power output from the panels is subtracted from customers’ bills through a virtual net metering arrangement, as if it were produced behind the customer’s meter.

Co-op power rates are 12.5 cents per kilowatt-hour in the summer, falling to 10.8 cents in winter. Co-op CEO Lynn Thompson calculates the levelized cost of solar at 8.1 cents per kilowatt-hour, making community solar quite attractive.

“Members are paying upfront for 20 years of energy,” he noted. “And I’m sure retail rates will rise over the next 20 years.”

Most co-ops in the area, including Eau Claire, are served by Dairyland, a coal-heavy generation and transmission co-op. But Dairyland is diversifying, taking bids now for 25 megawatts of solar.

Rural co-ops have led the way on community solar in Wisconsin. Four others have already built systems, with more plans in the works.

The Clark and Taylor electric co-ops both built community solar projects this summer. Clark’s 53-kilowatt system had a subscription price of $940 for a 360-watt unit of power. Taylor’s “Bright Horizons” program began in August, with its new 95-kilowatt system being sold in units of 350 watts each for a price of $945.

The small size of these systems was a factor in their higher cost, according to Thompson. It inspired Eau Claire to build a bigger system.

“It was a decision about how we bring value to our customers,” he said. “We took a little risk to build a larger system, and that helped drive the costs down.”

Thompson is still working on getting enough subscribers. “Some solar advocates thought it would sell out in days, and were asking us when we were going to build the second one,” he said.

So far they have sold 650 panels to 90 customers. At that rate, they would need just under 400 customers to fully subscribe. “We get calls every day,” said Thompson. “It just takes a lot of time to market. Enthusiasm doesn’t always translate into writing checks.”

There was no shortage of enthusiasm at Vernon Electric Co-Op when it offered a community solar product starting at an annual member meeting in March 2014. Developed by Clean Energy Collective, the 305-kilowatt system consisted of 1,000 ground-mounted panels.

The installation cost of $670 per panel was partially subsidized by the co-op, which runs its own conservation programs instead of sending money off to the state-wide Focus on Energy program. The cost to members was $600 per panel.

According to Dave Maxwell, director of marketing and communications for the co-op, they had a two-year marketing plan to sell subscriptions, starting with an article in the April newsletter. But “the phone rang off the hook,” according to Maxwell, and the whole system was bought up by 113 members within two and a half weeks.

“The marketing plan went in the garbage,” he said.

He thinks the presence of Organic Valley, a huge organic farming cooperative in Vernon County, was a vital factor. “So we have a large base of customers that like things that are local and green. Community solar meets both those criteria.”

Up to eight more community solar projects are in the works, according to Tyler Huebner of Renew Wisconsin. WPPI Energy, which supplies power to 51 municipal utilities, is developing 250-kilowatt projects for their member utilities in New Richmond and River Falls.

Xcel Energy’s Wisconsin operation is developing a community solar offering called Solar*Connect Community. Customers will be able to buy 200-watt shares of PV and get a cash credit on their monthly bill. The value of the power will be “based on Xcel Energy’s average cost of all generation resources currently in rates in Wisconsin,” which Deborah Erwin of Xcel estimates to be around 7 cents per kilowatt-hour, according to Midwest Energy News. Thanks to Minnesota regulations, Xcel’s community solar offerings in Minnesota will be valued at 12 to 15 cents per kilowatt-hour.

Madison Gas & Electric may be next in line, filing an application with the state Public Service Commission last week for a 500-kilowatt community solar pilot project. Unlike the co-ops, the utility will own the rooftop system and sell electricity to customers. MGE expects the fully loaded capital cost of the system to be only $1.89 per watt.

Under the proposed community solar tariff, customers would pay $189 per kilowatt upfront, then buy power at 16.2 cents per kilowatt-hour, fixed for 25 years. Customers would not be allowed to own the panels or to do virtual net metering.

Even though MGE’s solar system costs slightly less than Eau Claire’s, the community solar tariff is about 2.5 cents more per kilowatt-hour than the standard residential rate. Eau Claire’s solar rates are lower than standard residential rates.

However, the higher cost is comparable to MGE’s current renewable energy offering, Green Power Tomorrow, which has about 9,000 subscribers.

MGE triggered a customer revolt last year when it proposed raising a fixed customer charge from $10 to $69 per month. Faced with shareholder resolutions, picketers outside its headquarters, and legal opposition from the cities and county it serves, MGE reached a settlement with the Citizens Utility Board to limit the increase to $19 -- for now.

The prize for the largest solar in Wisconsin is at Epic Systems, an 8,000-person healthcare software company in Verona. With two arrays totaling 2.2 megawatts, Epic is doing what it calls “triple harvest.” The larger array is mounted on 13-foot-tall posts, allowing for alfalfa to be grown and harvested underneath. And under the alfalfa is a network of 2,500 ground-source heat pumps, providing heating and cooling for the massive office campus.