Avenue Garage taps the sun for power

Oak Park’s pursuit of environmental sustainability recently took a major step forward with the installation of a solar electric system installed atop the Avenue Garage.

The solar array mounted on the roof of the public garage on North Boulevard just east of Oak Park Avenue is the third largest municipal array in Illinois, and the largest garage-mounted system in the state.

An innovative mounting system of 50 tons of galvanized steel and extruded aluminum rails allows the array to integrate seamlessly with the garage structure. Vehicles can continue to park on the top deck under the mounting system.

The operation of the system is simple and automatic, with solar modules converting usable sunlight into clean, renewable electricity. Each module is comprised of several cells wired together in series. When sunlight strikes the modules, electrons embedded in the cells generate an electric current.

Wires from the modules carry the electricity into the garage where it passes through 12 inverters. The inverters change the electricity from direct current (DC) to alternating current (AC) and deliver it to the garage’s main electrical panel, making the power immediately available for use by the garage lighting and heating systems.

When the array generates more power than the garage needs, the energy is fed back into the grid for credit from ComEd.

A web-based remote monitoring system allows the public and the Village to obtain real-time information about the array’s performance, as information is captured from a dedicated weather station installed as part of the system. A link to the monitoring page is posted at www.oak-park.us/solar.

Each year of operation, the solar array will produce 106-megawatt hours and help protect the local environment by preventing the release of 76 tons of CO2, while eliminating an estimated 440 pounds of nitric oxide and 1,100 pounds of acid-rain forming sulfates.

Officials say this pollution offset is roughly the equivalent of planting 38 acres of trees every year.

The project was funded primarily by a grant from the Illinois Department of Commerce and Economic Opportunity, with funds from the American Recovery and Reinvestment Act. Oak Park expects to recover its investment in 10 to 12 years, a period that may be reduced further from the sale of renewable energy credits.