The U.S. Energy Information Administration estimates that lighting is responsible for approximately 38 percent of electrical energy in commercial buildings nationwide and that only 1 percent of commercial spaces have automated lighting control systems installed (2003 Commercial Building Energy Consumption Survey, Table E3A, and Detailed Table B43). When prorated by total floor space and census data, lighting accounts for up to 18 billion kWh of annual electrical consumption in the state of Minnesota. With such a large footprint, energy efficiency measures involving lighting have long been a target of utility Conservation Improvement Programs (CIPs).
The “Energy Savings from Task Tuning” CARD grant was awarded to the Energy Center of Wisconsin in order to address the strategy of using lighting controls to deliver exactly the right amount of light when it’s needed for the specific task being performed (Figure 2). There is evidence of significant energy savings potential from task tuning (sometimes called institutional tuning or high-end trim) in office and retail spaces. This project will verify savings and document best practices in order to increase designer and owner confidence in the expected performance of these systems and to provide justification to add the measure to CIP offerings.
Figure 2: Task lighting at the Shakopee Police Offices
This project will monitor eight to twelve lighting systems in Minnesota. The most likely building types for this study will be office, retail, and public assembly. Approximately half of the lighting systems—representing new construction projects—will already have implemented task tuning. In these buildings, the current settings and operation of the task lighting will be assessed in order to determine if additional savings can be obtained from recommissioning. The other half of the lighting systems—representing existing buildings—will be systems that have not implemented task tuning. In these systems, task lighting will be implemented to determine savings from task lighting retrofits. All lighting systems will be monitored prior to making any changes as well as afterwards so that savings from the modifications can be assessed. The Energy Center will also conduct occupant surveys in the buildings to gauge impacts on comfort and develop strategies for minimizing complaints.
The Division of Energy Resources’ project manager is Mary Sue Lobenstein; project results are anticipated by the end of April 2015.