LED-based solid-state lighting (SSL) now illuminates the Maines Paper & Food Service 400,000-square-foot warehouse in Conklin, NY. The Intelligent Lighting System supplied by Digital Lumens has reduced energy usage attributable to lighting in the warehouse to 13% of former levels – both through the more efficient LED technology and the integrated controls that can dim or extinguish lights in unoccupied parts of the warehouse.
The SSL installation replaced high-pressure-sodium high-bay lights in the Maines warehouse. Vice President of Operations at Maines Pat DeOrdio said, "We gained light level. We get 20 foot candles to the floor. The color of the light is much better and the light levels are higher."
SSL vs high-efficiency fluorescent
While the SSL is apparently superior to the legacy lights, Maines did consider other energy-efficient options. The ability to dim or extinguish LEDs was a key decision point for Maines according to DeOrdio. He said, "The LEDs are able to turn off completely unlike a high-efficiency fluorescent lamp that needs to stay on to stay warm creating heat and using energy. These lights turn on and off instantly."
DeOrdio explains that the warehouse has a number of refrigerated rooms including a freezer, cooler, produce room, and fresh meat room. High-efficiency fluorescents would have added to the refrigeration and lighting costs. DeOrdio added, "The lights would be on at least half even if no one is in the aisle."
Controlling the lights based on occupancy is the key to achieving the energy savings because the warehouse is a 24-hour operation, but at any given time many aisles are empty. DeOrdio describes the typical scenario where a fork lift triggers the lights in an aisle while retrieving a pallet. Depending on the situation, the system is set to extinguish the lights after 30 seconds to a minute.
DeOrdio states, "In certain areas coming around corners and between cross aisles, we want to make sure it's safe for employees, and we have the lights set at 10% on all of the time." The lights are driven to full brightness based on occupancy.
Intelligent Lighting System
Digital Lumens is a startup player in the SSL space that introduced its Intelligent Lighting System back in March. The system integrates SSL with network and control technologies and includes software that facility manages can use to program operation.
The Digital Lumens' system relies on Zigbee wireless technology to link the network-enabled luminaires in a mesh network. But the Maines installation covers a far greater space than a single Zigbee network can support.
Digital Lumens CEO Tom Pincine stated, "It is 7, 8 or 9 football fields in size. It's also segregated into rooms. Each room has its own Zigbee gateway. The entire facility is not run by one Zigbee mesh."
The Zigbee gateways connect back to the Maines computer network via Ethernet allowing control by any computer on the network. According to DeOrdio, the Maines facility manager immediately took to the technology both setting dimming parameters and controlling the lights via a laptop computer.
Ultimately, Maines chose SSL because it offered a faster payback than high-efficiency fluorescent lights even though the LEDs cost more up front. The installation was in part covered by a grant from the New York State Energy Research and Development Authority (NYSERDA). Moreover NYSERDA has visited the facility and validated that the system provides the projected energy savings.