A recent study by the Energy Center of Wisconsin and funded through a grant from the Minnesota Department of Commerce, Division of Energy Resources, found that daylight harvesting, or daylighting control, can lead to significant energy savings. According to the energy organization, energy savings can be 60 percent or more with sustainable lighting solutions.
Daylight harvesting has become more common for those who want to save energy, however, execution of the lighting control system is failing to break into mainstream construction because the design of daylighting controls is often an afterthought.
Daylight harvesting controls use light sensors to reduce electric lighting in a room when sufficient natural light is present, according to the Lighting Controls Association. Although daylight harvesting has had a hard time becoming mainstream in the past, all commercial buildings in the United States are required to adopt a commercial building energy code by October 2013 and could increase the adoption of daylight harvesting.
During the study, the Energy Center tested 20 office and public assembly spaces in Minnesota and Wisconsin to collect sub-hourly measurements of light levels, lighting power, and heating and cooling data from January 13, 2012, to July 10, 2012.
“When installed, commissioned, and operated to perform as designed, daylighting controls can be an economically attractive solution,” the researchers said in the report. “With the levels of performance we measured, owners break even at a cost of $1,000-$2,000 per kilowatt-hour of controlled lighting for these systems, which is in line with current system costs. This opportunity is most promising in new construction or major renovation, where daylighting can be included as part of the design. But there are retrofit opportunities wherever daylight is abundant.”
