Next month, Minnesota's second-largest solar panel installation should begin generating electricity at Hennepin County's public works facility in Medina.

Almost 530 panels have been installed on the roof of the building, with work finishing earlier this month. At its maximum, the panel system will generate 80 kilowatts of electricity, providing up to 15 percent of the electric power used in the building. That would save about $15,000 in electricity charges per year.

In Minnesota, the solar complex on the roof is second in size only to an installation at Merrick Inc. in Vadnais Heights, which supplies 100 kilowatts of power.

"The county is trying to be a leader in renewable energy and conservation and sustainable buildings," said Dave McNary, Hennepin County's assistant director of environmental services in charge of energy and solid waste. "If we generate electrical energy from renewable resources, we can reduce reliance on fossil fuels."

Built in 1997, the Medina building was one of the first in the state to use sustainable building design, including such energy-efficient ideas as large windows and skylights that provide natural lighting and use of recycled materials, McNary said. The county Transportation Department is housed there, with garages as well as engineers, designers and support staff.

The solar project was approved in 2007 at a cost of about $900,000, paid from the county's capital fund.

The 300-pound solar panels came from China and arrived around Christmas. County officials believed they were lucky to get them.

"It's not as easy to get solar panels as you might think," said Andy Leith, senior environmentalist with the county's air and energy unit. He said a big push for solar use in Germany means that nation "is taking a big chunk of the solar panels that are marketed."

The panels, which are made of smaller modules, are about 5.5 feet long and about 2.5 feet wide. More than 20 rows of the panels sit above the roof, mounted on beams that are raised above the roof so the county can replace the roof if need be without disabling the panels, which are under warranty for 25 years.

The county is looking for other buildings that might be suitable for solar installations, McNary said. Part of Hennepin's "cool county" initiative is a commitment to reduce greenhouse gasses produced by the county by 80 percent by 2050, he said.

The panels are expected to begin generating electricity by March 15.

Later this year, a wind turbine will be added to the Medina site. A vendor will be chosen this spring and the turbine should be up by fall, McNary said. The $3 million project is being paid for with special federal energy bonds. Electricity from the turbine will be sold to local utilities.

Mary Jane Smetanka • 612-673-7380