Lighting controls update
The DesignLights Consortium’s new report, “Energy Savings from Networked Lighting Control (NLC) Systems,” estimated average lighting energy savings of 47% resulting from installation of networked lighting control systems. The report indicated a high potential of energy savings for networked controls, it supported layered control strategies as a means to maximize savings and it may be used to justify new and larger utility rebates.
Networked lighting control systems are intelligent, programmable systems capable of communication, including to a central point for measuring and monitoring. Despite high energy savings potential, adoption by projects and rebate programs alike has been inhibited by difficulty in estimating these savings.
To address this barrier, the DLC embarked on an ambitious study to determine average lighting energy savings resulting from installation of networked lighting controls. The DLC report analyzed hourly energy data monitored in 1,200 zones in 114 commercial buildings to produce an average estimate.
It compared LED lighting with networked controls operating against a baseline consisting of what energy use would be if the lighting was on and at full output during operating hours. This methodology provided a standardized way to evaluate savings in a wide range of zones and control systems.
According to the report, networked lighting control systems reduced installed LED lighting energy consumption in the studied buildings by nearly one-half, compared to the LED lighting installed without controls. Results varied widely from 2% to 91%. About 70% of the projects generated 30% or more energy savings, while 30% generated 70% or more energy savings.
Warehouses consistently showed greater than 75% energy savings — but otherwise, building type was a poor indicator of energy savings. Space characteristics such as occupancy patterns, daylight availability and user behavior had far more impact.
Most influential was implementation of layered control strategies and more aggressive configuration settings. DLC speculated the lowest-performing systems appeared to be primarily focused on scheduling control, while the highest-performing systems implemented layered strategies, including high-end trim, and featured aggressive configuration settings.
Meanwhile, utilities and energy efficiency programs are likely to use this report to justify new and expanded rebates for networked lighting controls. In the case of an existing building, be sure to investigate availability of these rebates. The rebate may require the system to be listed in the DLC’s Qualified Products List for Networked Lighting Controls.
The DLC is planning a follow-up study that will expand the building database and add more characteristics to explore. This will allow DLC to examine which building and space characteristics contribute to energy savings and which control strategies, zoning and configuration settings produce the highest savings. The target result will be greater certainty in projecting energy savings and information that can be used to develop best practices.
Craig DiLouie, LC, CLCP, is the education director of the Lighting Controls Association.