What business has one of the largest solar arrays in Duluth? It's a grocery store.

DULUTH — Whole Foods Co-op recently added 145 solar panels to the roof of its Denfeld neighborhood shop, a $180,000 investment that is expected to offset the grocery store's total electricity use by 25%.

That's on top of a 48-panel array that was added to the West Duluth store's southwest wall after it opened in 2016.

With the addition of the new roof-mounted panels, installed over a week in August, the co-op has one of the largest commercial arrays in the city.

"This is a long-term dream of the co-op's," said co-op general manager Sarah Hannigan, during an unveiling for the project Wednesday morning. "When we started thinking about expansion, we started about thinking about how we could have a larger community impact."

The co-op, which expends the most electricity on refrigeration, is expecting to generate 96,000 kilowatt hours of electricity every year. Add in the co-op's East Hillside store — which has a less-efficient 16-panel array from 2007 in its employee parking lot — and they could generate more than a combined 100,000 kilowatt hours.

This is about the equivalent of what is used annually in nine homes in the United States, noted marketing director Marci Strack.

The co-op received financing from the St. Paul Port Authority's Property Assessed Clean Energy Program, and expects to pay it off over time with the utility savings, according to Strack. The project was scheduled to begin before the pandemic, but the wait put the company in a better position: It will benefit from tax incentives from the federal Inflation Reduction Act — which could offset the cost by up to 40%, Hannigan said.

There are other significant-sized solar arrays at the new Heikkila Chemistry & Advanced Materials Science Building on the University of Minnesota Duluth campus and at the Unitarian Universalist Congregation of Duluth. The largest in the city is owned by Minnesota Power, which added 1.6 megawatts on Riley Road and Jean Duluth Road last year, according to the city's sustainability officer Mindy Granley. Duluth's own solar canopy in Canal Park is 48 kilowatts.

"But, overall, the residential adoption of solar has outpaced the commercial adoption in the city of Duluth," Granley said.

At the end of 2022, 85% of solar installations were on residential properties, according to Katie Frye of Minnesota Power.

Not-so favorable weather conditions didn't hinder a ribbon cutting at the member-owned grocery store — or the sun-powered panels on top of the building.

"We are grateful for the opportunity to celebrate our solar project in the middle of the rain — but honestly that project is still generating electricity right now," Hannigan said.