Lighting accounts for about a third of electrical energy consumption in commercial buildings. As advanced energy-saving lighting controls still have a minority penetration in the existing building stock, building owners have a major opportunity to reduce energy costs with lighting control.
Adoption of advanced lighting controls faces the usual hurdles affecting all energy-efficient lighting, including a focus on initial cost and lack of education about benefits. A particular challenge unique to controls, however, is estimating energy savings.
When lamps and ballasts are replaced, energy savings are easily quantified by subtracting the new lighting system power from the old system power, and then dividing that figure by the old system power. With lighting controls, many factors come into play that can affect projected energy savings, all of them specific to the application characteristics, such as occupant behavior, building design, site orientation, daylight apertures, interior reflectances, and system settings and level of commissioning.
The Lawrence Berkeley National Laboratory (LBNL) analyzed 240 energy savings estimates from 88 papers and case studies. Using filtering to focus on lighting energy savings only produced by lighting controls only in actual field installations only (as field simulations were found to overestimate savings), LBNL produced best estimates of average lighting energy savings for these strategies:
Strategy
Definition
Examples
Average Savings
Occupancy
Lighting status changes automatically based on presence of people
Occupancy sensors, timeclocks, energy management system
24%
Personal Tuning
Occupant control of light levels
Dimmers, wireless switches, workstation-specific control, preset scene control
31%
Daylight Harvesting
Lighting status changes automatically based on daylight levels
Photosensors
28%
Institutional Tuning
Light levels tuned to space needs by application, ballast tuning (reduction of ballast factor), task tuning, lumen maintenance, group controls
Dimmable ballasts, and dimmers and switches used to control group lighting
36%
Multiple Strategies
Any combination of the above
38%
The methodology and results were condensed into a paper published in the January 2012 issue of LEUKOS. The authors concluded:
“This meta-analysis shows that individual control strategies save on average between one-quarter and one-third of lighting energy, and multiple controls strategies can capture up to nearly 40 percent savings on average.”
They added:
“The results of this meta-analysis, viewed in aggregate, provide strong evidence that currently available lighting controls strategies can and do provide significant lighting energy savings in commercial building applications.”
The Ballastar T8 Light Level Switching Ballast from Universal Lighting Technologies allows users to switch light levels from 100% to 50%, or 100% to 60% to 30%, using standard wall switches and relays. The application benefits from uniform step dimming, with no dark spots and shadows in the light fixture or the illuminated space.
Universal offers a brochure describing the Ballastar T8 product line here.
Adapted from an article originally published in the July issue of Illuminate Magazine. Used with permission.
Project: Sears Distribution Center Owner: ProLogis Tenant: Sears Holdings Corporation Location: Stockton, CA Architect: Ware Malcomb Lighting Design: Exposure Illumination Architects, Inc. Electrical Engineer: ACIES General Contractor: Big-D Pacific Photography: Exposure Illumination Architects, Inc., Cooper Lighting
In 2006, Sears Holdings Corporation concluded a year-long study to produce an outline of the ideal built-to-suit facility to support its distribution network, and decided to replace five of its older facilities with new state-of-the-art centers.
In 2007, the company engaged ProLogis, a leading global provider of distribution facilities, to build a LEED-certified 780,400-sq.ft. distribution center in Stockton, CA, the last of the five. The new distribution center would be used to store and distribute big items such as washers, dryers and refrigerators. ProLogis, in turn, engaged Ware Malcomb, an architecture and design firm.
“Sears wanted a reliable, low-maintenance facility that met its standards,” said Jim Terry, Director, Commercial for Ware Malcomb. “ProLogis wanted to provide an energy-efficient, comfortable, functional environment that was of higher quality than typical distribution buildings. Ware Malcomb utilized unique architectural elements, including a suspended trellis canopy, bold entry articulation and consistent architectural treatment—paint, panel massing, clerestory windows—across the entire façade to bring a level of quality not typically seen in a large distribution facility.”
For the lighting, ProLogis and Ware Malcomb collaborated with Scottsdale, AZ-based Exposure Illumination Architects, Inc. In the RFP for the built-to-suit facility, Sears specified a maintained 30-footcandle light level, which it believed would support an environment conducive to safe and productive work among the 28-ft.-high product storage bins. ProLogis wanted these needs satisfied by a highly energy-efficient lighting system consistent with the company’s leadership in sustainable warehouse design.
The result was one of the most energy-efficient warehouse buildings in the country, with an effective lighting power density of 0.18W/sq.ft.—78% less than the maximum prescribed by California’s Title 24 energy code.
“For lighting designers focused on energy conservation, getting in early in the process is critical, allowing us to take responsibility not just for the lighting and controls, but also the total daylighting solution,” said Daniel S. Spiro, AIA, IES, president of Exposure Illumination Architects, Inc. “This involves educating the owner and design team at the front end of the design process about energy savings potential. Later in the process, once budgets are set, it’s very hard to make a change.”
In working on previous warehouse projects with ProLogis, Exposure Illumination Architects favored hi-bay fluorescent lighting as an alternative to more traditionally favored metal halide for a number of benefits, most notably high energy savings. For this project, Spiro envisioned integration of fluorescent lighting and daylighting using advanced lighting controls to dramatically maximize energy savings.
After receiving the product storage bin layout plan from Sears, which showed the fixed locations of the bins in the 600,000-sq.ft. storage space of the building, the lighting designers specified approximately 16,000 linear ft. of Cooper Lighting’s Metalux MB Series T5HO Micro-Bay luminaires in 360-ft. linear rows mounted 32 ft. off the floor. Select luminaires were specified with emergency battery backup, providing mandatory illumination throughout the warehouse in the event of a power outage without the need for a backup power generator.
“The Micro-Bay luminaire’s profile is extremely narrow, which increased design flexibility,” says Spiro. “The building code required obstructions wider than 2 ft. to be at least 2 ft. away from sprinkler heads. By being less than 1 ft. wide, we were able to place the luminaire within 1 ft. of the sprinkler heads. We gained valuable flexibility in placement. The luminaire could be as close as possible to the aisle center as a result.”
The luminaire’s narrow profile also enabled the electric lighting to integrate with the building’s daylighting strategy by minimizing blockage of daylight entering the space through a series of skylights also aligned over the center of each aisle. Except on cloudy days, these 4-ft. by 8-ft. double-dome skylights by manufacturer Bristolite, which are placed 40 ft. apart on center and cover 2% of the roof area, are able to meet target light levels without requiring any electric lighting during the daytime.
“Over 90% of the space has daylighting via skylights and clerestory windows,” Terry points out. “While not typical in industrial and distribution buildings, from past Ware Malcomb projects where we’ve employed extensive daylighting design, companies have noticed low employee turnover and increased productivity. Daylighting creates employee connection to the outside environment.”
One of the primary advantages of fluorescent over metal halide is its instant-ON operation, making automatic energy-saving switching strategies much easier to implement. This allowed the lighting designers to go beyond producing desired light levels for fewer watts, and look at what additional savings controls could bring to the table. By specifying luminaire sections adjoined in continuous runs, multiple circuits could be installed along the run, enabling granular zoning of sections in the row to support different control strategies such as daylighting control and occupancy sensing.
A Cooper Controls Greengate lighting automation system, which controls all of the building’s lighting at the lighting panels, turns the lights along critical pathways and aisle entrances ON before dawn. For example, in the bulk storage area, 16-ft. luminaire sections located at the head of each aisle are switched and kept ON all day for safety reasons. The rest of the lighting in each row is divided into 40-ft. sections, each controlled by its own integral occupancy sensor. In the late afternoon, as falling light levels are detected, the control system restores power to the lighting circuits; the lights remain OFF, however, unless occupancy is detected by the connected occupancy sensor, which turns the lights ON in the immediate area.
As daylight levels increase on the following morning, raising ambient light levels above a target threshold (as preset for local zone photosensors installed in select skylights), power to the non-critical lighting circuits is cut off. Multiple photosensors are used, dividing the lighting into nine daylight control zones, increasing sensitivity and flexibility based on an understanding that lighting conditions may vary in different parts of the building throughout the day.
“Stockton benefits from 310 days per year of clear skies, 55 days with semi-cloudy conditions, and only 16 with overcast conditions,” says Spiro. “On an average day, between 9 AM and 5 PM, most of the electric lighting is OFF in the building, saving energy.”
As falling light levels are detected by a photosensor in the late afternoon, the Cooper Controls Greengate control system restores power to the lighting circuits feeding about 16,000 linear ft. of luminaires mounted 32 ft. off the floor. The lighting remains OFF, however, unless occupancy is detected by the connected occupancy sensor, which turns the lights ON in the immediate area.
Meanwhile, in the other major space in the building, the 134,000-sq.ft. dock bay/staging area, 2×4 6-lamp T5HO luminaires provide general lighting, dual circuited so that two lamps provide 33% light levels for security purposes at all times. The circuit feeding the remaining four lamps is energized only if insufficient daylight is available, such as on cloudy days or at night, and then only if occupancy is detected.
Sears, which benefits directly from the operating cost savings based on their lease with ProLogis, is enjoying a projected 2.75 million kWh/year energy savings, which adds up to significant annual cost savings—$399,000—based on a local utility rate of $0.145/kWh (compared to a standard HID solution complying with Title 24’s requirement of 0.8W/sq.ft. maximum power allowance).
Monitoring to date [May 2009] has confirmed projected savings, measuring an average $0.0225/sq.ft./month electrical operating cost (lighting plus battery chargers) for the four winter months. Savings are expected to escalate during the summer—when the sun angle is higher, daylight hours are extended and utility rates typically increase—which are expected to reduce energy costs to as low as $0.0125/sq.ft./month, says Spiro. Annual energy costs are projected at $0.20-0.22/sq.ft. The next highest energy-performing building in all of Sears’ warehouses is $0.34/sq.ft./year (the worst is $0.58/sq.ft./year).
After an incentive provided by the local utility, PG&E, reduced the incremental labor, material and design costs, the energy savings is expected to recoup the net cost in less than eight months—a return on investment of 154%.
“A relatively small increase in initial construction costs for adding skylights and clerestory windows can quickly pay for itself in electricity costs and employee well-being,” says Terry.
“I would summarize this project with a simple statement,” says Spiro. “More costs less.”
Philips Lighting Controls recently announced the launch of its new and improved website at www.philipslightingcontrols.com. The new site features:
• Clean, modern design with quick and easy access to Philips Lighting Controls solutions. Electrical contractors, facilities managers, lighting designers, engineers and other lighting professionals now have access to more information than ever.
• Products page providing a high-level overview of the Philips Lighting Controls portfolio. Individual product pages have links to data sheets, drawings, installation guides, and user manuals.
• Gallery featuring businesses around the world using Philips Lighting Control products such as Dynalite, Energy Efficient IGBT Dimming and other solutions.
NEMA LSD 56-2011, Compatibility of Forward Phase Control Dimmers and Dimmable Self-Ballasted Compact Fluorescent Lamps and Frequently Asked Questions Regarding CFLs and Dimming, provides design guidance in the area of lamp/dimmer compatibility to the manufacturers of dimmable self-ballasted CFLs that use forward phase control and the manufacturers of forward phase control dimmers. The values provided assume operation under nominal line conditions, i.e., 120 V, 60 Hz. In practice, actual voltages can vary by ±10% in the field.
LSD 56-2011 contains a related FAQ, which is meant to provide answers to frequently asked questions regarding CFLs and dimming.
Schneider Electric and Tridonic recently announced a strategic partnership. The corporate partnership represents collaboration around projects business, and will see the companies work together to promote energy efficient lighting control solutions to customers.
Schneider Electric operates in more than 100 countries and, through its diverse product and business portfolio, specialises in the design and implementation of lighting control systems. Tridonic, headquartered in Austria and part of the Zumtobel Group, enables customers around the world to develop innovative applications and solutions, through lighting components, lighting management systems, connection technology and LED solutions. Within the partnership there is a project with LEDON, a sister company of Tridonic, which develops and markets hi-tech LED retrofit lamps for private consumers.
The strategic partnership between the businesses will combine the product innovation and market pedigree from the companies to develop cutting-edge, energy efficient lighting control solutions for customers globally. The solutions will meet the needs of diverse market sectors, including airports, hospitals, infrastructure and high performance green buildings. Schneider Electric benefits from Tridonic’s deep know-how in electronic control gears as well as from the innovative Tridonic products. Tridonic benefits from Schneider Electric’s excellent customer relations in the project business where Tridonic takes the role as first choice partner for lighting management. In all cases customers will stand to benefit by receiving lighting systems with synchronised components from one hand and enjoying service and safe systems.
The International Electrotechnical Commission (IEC) has ratified a new standard–ISO/IEC 14543-3-10–for wireless applications with ultra-low power consumption pioneered by EnOcean. The standard can be downloaded from www.iso.org.
The new standard is geared to wireless sensors and wireless sensor networks with ultra-low power consumption. It also includes sensor networks that utilize energy harvesting technology to draw energy from their surroundings–for example, from motion, light or temperature differences. This principle enables electronic control systems to be used that work independently of an external power supply.
Specifically, it covers OSI (Open Systems Interconnection) layers 1-3, being the physical, data link and networking layers. The full title of the standard is: ISO/IEC 14543-3-10 Information technology–Home Electronic Systems (HES)–Part 3-10: Wireless Short-Packet (WSP) protocol optimized for energy harvesting–Architecture and lower layer protocols.
International standardization will accelerate the development and implementation of energy-optimized wireless sensors and wireless sensor networks. It will also open up new markets and areas of application for energy harvesting solutions. In addition to the already established markets for home and building technology, there will be further uses ranging from the smart home, smart metering and the smart grid to solutions for industry, logistics and transport.
Members of the EnOcean Alliance have already introduced more than 850 EnOcean-based, interoperable products, all of which comply with the new standard. Developers and manufacturers can therefore benefit from the Alliance’s extensive practical experience, huge product range and installed base, and many years of user education.
Leviton recently announced the promotion of John LaMontagne to the position of Vice President of Sales for the company’s Lighting Energy Solutions business unit. In his new role, LaMontagne will be responsible for the sales and specification of Leviton’s broad portfolio of lighting systems, metering and energy management products.
LaMontagne most recently served as the Director of Technical Sales for Leviton’s Lighting Energy Solutions group. He initially joined Leviton in 1994 as a Specification Engineer working for the Electrical Distribution group. He played an integral role in the launch of this group and was instrumental in building Leviton’s commercial and industrial initiatives in the Northeast. LaMontagne then moved to a corporate training position where he continued to develop Leviton’s technical support and training capabilities. In 2001, he was promoted to Eastern Region Sales Manager of Lighting Management Systems and spearheaded the growth of this significant energy management initiative.
DSIRE is a comprehensive source of information on state, local, utility and federal incentives and policies that promote renewable energy and energy efficiency. Established in 1995 and funded by the U.S. Department of Energy, DSIRE is an ongoing project of the N.C. Solar Center and the Interstate Renewable Energy Council.
Click here to see a comprehensive list of energy efficiency and renewable energy incentives/policies that include lighting.
This short video, produced by the Lighting Controls Association at the 2011 LIGHTFAIR event, introduces the building industry to WattStopper’s intelligent building strategies based on the company’s Digital Lighting Management (DLM) product line.
An all-digital suite of plug-together lighting controls, DLM automatically configures to the most energy-efficient sequence of operation based on installed components. The result is that DLM meets and exceeds energy code requirements, saves more energy than conventional controls, and provides an unprecedented return on investment for both new construction and retrofit projects.
With DLM, each room or space in a building has its own control network where the installer simply connects room controllers, occupancy sensors, switches and photocells as needed. Plug n’ Go technology then recognizes what is connected and automatically configures the space to the most energy efficient operation. For instance, advanced controls strategies such as automatic-on of 50% of lighting with manual-on of the remaining 50% automatically configure when appropriate DLM components are connected. Other DLM innovations include LCD screens on occupancy sensors for ease of setup, as well as a handheld bidirectional configuration tool that provides ladder-free system setup or adjustment. Because DLM uses Cat 5e RJ45 cables to connect components, time-consuming installation activities, such as interpreting wiring diagrams, setting DIP switches, and terminating low voltage wires, are eliminated. This speeds up installation and eliminates the potential for wiring errors.
DLM also offers integration of plug load control, allowing building owners to further leverage code-compliant occupancy sensors and realize greater savings. Most recently, the company expanded the DLM offering with components that allow quick and easy networking of room-based controls and lighting control panels for centralized monitoring, control and programming.
The Ballastar T8 Light Level Switching Ballast from Universal Lighting Technologies allows users to switch light levels from 100% to 50%, or 100% to 60% to 30%, using standard wall switches and relays. The application benefits from uniform step dimming, with no dark spots and shadows in the light fixture or the illuminated space.
