In addition to providing automotive interiors and batteries, Johnson Controls, Inc. (JCI) offers building efficiency and power solutions to customers worldwide. So when the Fortune 100 company decided to expand and remodel its Glendale, Wis.-based headquarters, the firm showcased its “green” expertise by constructing the first LEED Platinum-certified facility in the state — and the only campus in the country to include multiple LEED Platinum-certified buildings (four in all).
A major part of the $75-million project included the addition of a ground-mounted solar photovoltaic (PV) system to help power the company's 33-acre campus. Prominently situated on the property's main access road, the 31, 115-sq-ft array is comprised of 1,452 panels, each measuring 5 ft long by 32 in. wide and generating 33VDC of power.
“The ground-mount system is a very visible sign of JCI's commitment to sustainable building,” says Steve Griffith, field coordinator for Waukesha, Wis.-headquartered Venture Electric, the contractor that performed the solar PV installation. “As far as we know, it is the largest ground-mounted solar field in Wisconsin.”
According to Griffith, the 254kW system has the capability of powering the corporate north building, which equates to the load of 40 average homes. This means that, on an after-tax basis, the solar field should have a four- to five-year payback.
“Better yet, the system is virtually maintenance-free,” observes Marty Schultz, Venture Electric field foreman. “The rain and snow melt washes the panels off.”
Perhaps what made this project most unique — not to mention challenging — for Venture Electric is the geothermal heating and cooling system, consisting of 272 wells located directly beneath the solar array.
“The geothermal system, which is basically constructed of PVC pipe, was put in place before the solar PV array,” says Venture Electric Project Manager Jim Seefeldt. “Marty and his crew had to be very careful not to hit any of those pipe wells when installing the rack system.”
Furthermore, each panel of the solar PV array had to face exactly due south at a 30° angle to achieve maximum sunlight and prevent snow from accumulating on them.
“Certain distances had to be maintained between each rack, which was approximately 15-ft clearance for shading purposes,” notes Schultz. “The system is set up so that it can produce electricity on cloudy days or even if it's snowing.”
The snow and bitter cold also presented a challenge to the workers involved in the installation.
“We began the project on October 9 and finished on December 31,” says Griffith. “During that time, there were 10 consecutive days of snow and below-freezing temperatures. The solar array is an intricate maze of pipe work that required approximately 12,000 nuts and bolts to construct. Doing this while wearing gloves was difficult at best.”
Thanks in large part to the solar PV field and geothermal system, Griffith says JCI's energy usage will only increase 25%, despite almost doubling in size. Moreover, surplus energy generated by the two systems can be placed back onto the electric utility's grid.
“It's been an honor to work with JCI,” adds Jeff Robertson, Venture Electric president. “The experience and knowledge we gained from being involved in this project has cast our company into the forefront of the green movement in Wisconsin. It is a leadership role we relish.”