Solar gardens are sprouting in Minnesota.

These innovative solar power projects allow electric customers to invest in a large array off their property and own a share of the output, which gets credited to their monthly bills.

The first solar garden, a large ground-mounted system, is nearly finished in Rockford, next to the headquarters of its sponsor, the Wright Hennepin Cooperative Electric Association, which says it plans to immediately build a second one.

In Minneapolis, start-up company MN Community Solar said Thursday that it expects no shortage of investors for that city’s first planned solar garden atop a business on E. Lake Street.

“The majority of residential customers and many businesses don’t have a roof that works for solar energy,” said the company’s CEO Ken Bradley, a longtime solar energy advocate who helped push adoption of the state’s new solar law, passed in May by the Minnesota Legislature. “Community solar gardens allow anyone to participate.”

Dustin Denison, a company principal, said it hopes to begin construction next year on the planned 40-kilowatt solar array, which is expected to cost $180,000. It will be built atop Northern Sun Merchandising, a seller of T-shirts, buttons and other products with progressive political messages at 2916 E. Lake St.

Denison, who is also a solar installer, said MN Community Solar is looking to build even-larger solar arrays, and has begun talking to cities and businesses about potential sites. Some of those arrays could be 1-megawatt systems, or 25 times larger than the one planned on Lake Street, Denison said.

Minneapolis Mayor R.T. Rybak, a green energy supporter who came to Lake Street on Thursday for the company announcement, said the city likely has properties on which community solar projects could be built.

Meanwhile, the state’s first solar garden neared completion this week in Rockford, and should be wired into the electric grid and...