DLC Estimates Energy Savings from Networked Lighting Controls

The DesignLights Consortium’s (DLC) new report, Energy Savings from Networked Lighting Control (NLC) Systems, estimates average lighting energy savings of 47 percent resulting from installation of networked lighting control systems. The report indicates high potential energy savings for networked controls, supports layered control strategies as a means to maximize savings, and 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 energy 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 controls 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 two to 91 percent. About 70 percent of the projects generated 30 percent or more energy savings, while 30 percent generated 70 percent or more energy savings.

Warehouses consistently showed greater than 75 percent 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.

Lighting professionals can reference the 47 percent average lighting energy savings to demonstrate the value of these control systems. To achieve this or a higher energy savings level with specified networked control systems, they should:

• Write a detailed sequence of operations for each control point and communicate this narrative to the project team and owner.
• Ensure the owner is taking advantage of layered control strategies wherever practical.
• Invest in understanding the full feature set for the selected system.
• Properly calibrate and configure the system to optimize both user comfort and energy savings.
• Provision training on the control system’s use for the owner.

Utilities and energy efficiency programs, meanwhile, are likely to use this report to justify new and expanded rebates for networked lighting controls. If an existing building, be sure to investigate availability of these rebates. The rebate may require the system be listed in the DLC’s Qualified Products List for Networked Lighting Controls.

The DLC is planning a follow-up study in 2018 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 what control strategies, zoning, and configuration settings produce the highest savings. The result, it’s hoped, will be greater certainty in projecting energy savings and information that can be used to develop best practices.

Download the report at www.designlights.org.