Working Together
Author: Kathryn Kirkland
Posted: September 30, 2010


A UNIVERSITY CHEMIST, engineer, and botanist have joined forces in a groundbreaking study to see if placing solar panels on an ecoroof can help each run more efficiently.

Professors Carl Wamser, David Sailor, and Todd Rosenstiel have installed 720-square-feet of ecoroof—soil, sedums, and other plants—partially shaded by 16, 175-watt solar panels on the south roof of Science Building 2.

Combining ecoroofs and solar panels has traditionally been an either/or decision, says Wamser. “It just doesn’t occur to people to do multiple things with their roof, nor that plants and panels can be mutually beneficial.”

In addition to reducing stormwater runoff, insulating a building, and creating wildlife habitat, ecoroofs cool ambient air, which is a plus for solar panels, explains Wamser. The silicon in photovoltaic cells transmits electricity more efficiently at cooler temperatures resulting in higher output. Electricity from the panels is being used in Science Building 2, which is undergoing an extensive remodel scheduled for completion in March.

The benefits roll the other way, too. The solar panels may provide an ideal, shaded environment for ecoroof vegetation. Sedums are often chosen because they can handle summer’s lack of rain. With shade, sedums and other plants might better thrive and provide superior cooling.

The scientists will make available video of the plants and compile statistics on electricity output and soil and air temperature into a database. Both will be available online for anyone willing to consider creating a roof that does it all.