Advanced Lighting Control Systems
Lighting Control: Automated Centralized or Decentralized vs. Manual ,Time Clock or Single-Sensor Controlled
Advanced lighting control systems, either with wireless sensors, or with luminaire integrated lighting controls, provide occupancy-sensor and light-level control plus energy metering.
Item ID: 117
Lighting--Sensors & Controls
Technical Advisory Group: 2009 Lighting TAG (#1)
Technical Advisory Group: 2013 Advanced Lighting Controls Systems TAG (#7)
Advanced Lighting Control Systems (ALCS), often utilizing wireless control systems, have shown 50-70% energy savings by providing capabilities for scheduling, dimming, occupancy sensing, daylight harvesting, personal control, and demand response. Wireless systems are ideal for retrofits as they are much less disruptive to occupants, and installation is much less labor-intensive, usually reducing installed costs. Should space arrangements change, the controls are easy to move and reprogram from a computer. Large facilities are able to control multiple floors or buildings with these systems and can be controlled and managed centrally for system wide operations. The two-way communication of the various sensors to the controller assists in energy management and trouble-shooting.These systems work well with the smart-grid technology being deployed in many areas, making them good candidates to include in demand response programs, and should comply with upcoming code requirements on lighting controls.
An alternative to wireless or central control schemes is the advancement of luminaire-level lighting controls (LLLC). This integrated lighting control approach combines local sensor inputs for dimming and daylighting control, occupancy sensor, and energy metering. Given distributed control at each luminaire, a central controller is unnecessary. Like central controls, LLLC offers the potential to provide 50% to 60% lighting energy savings (Navigant Consulting, 2014).
Baseline Description: Commercial Building with Uncontrolled Lighting
Baseline Energy Use: 4.7 kWh per year per square foot
Warehouse Example: Warehouses serve many purposes from inactive, unconditioned storage to retail stores and more, each with their own lighting requirements. Though fluorescent lighting has been replacing high intensity discharge (HID) lighting in warehouses where better light and some controls were desired, 400W high pressure sodium (HPS) or metal halide (MH) is probably still the most common legacy light. It performs best with long operating hours and is not suitable for occupancy controls. If not on around the clock every day it may be on for 10 hours daily or weekdays. For the base case a warehouse(Mutmansky, 2013) with active storage and 400W metal halide lighting is considered. Some skylights are in place but no controls respond to them.
Both the 2006 and the 2009 Editions of the WA State Energy Code impose a maximum lighting power density of 0.5 W/sf for warehouse space. Annual energy use would be expected to range from 1.82 to 4.38 kWh/year given 10 hours of operation per day for 7 days per week versus 24/7 operations. An "average" of 3.1 kWh/sf-year is a reasonable baseline for warehouse applications.
Total Commercial Sector: The average interior commercial sector lighting power density is 1.15 Watts per square foot. Average building occupancy is 79.3 hours/sf leading to a lighting system average annual energy use of 4.74 kWh/sf-year (NEEA, 2009), Table C-SC2). This energy use per sf will be used to represent a lighting system baseline for the region.
Manufacturer's Energy Savings Claims:
"Typical" Savings: 50%
Savings Range: From 25% to 50%
The energy savings potential will depend more on how the controls system is implemented than on whether the sensors are wireless or not. Because the controls do not work with all technologies, additional savings from switching to fluorescent or LED systems in order to use the controls will have a significant impact on energy use and demand as well and may be embedded in some advertising claims of more dramatic savings. Savings should be about the same as similar application with wired sensors. (See information on bi-level lighting applications and daylight harvesting systems.) In real-life applications, the wireless systems may provide more savings over the life of the system because of the ability to change configuration and application inexpensively.
The wireless lighting control system manufacturer Adura Technologies (now part of Acuity Brands) projects 30% to 50% savings for their product over an existing occupancy sensor control. At the two UC Berkeley library demonstration sites, Adura installation savings were 3 kWh/sf-year and 5 kWh/sf-year.
A Life Cycle Cost (LCC) Evaluation of Multiple Control Strategies used computer analyses of hypothetical facilities in Boston and Los Angeles. These analyses found that advanced lighting controls, particularly full dimming wireless lighting control systems with addressable or networked, dimmable ballasts, were an economical option, saving almost 50% more energy than code compliant controls (achieved the lowest LCC over ten years of six systems studied). Further, the energy savings more than compensated for the first costs, which were not significantly higher than code mandated control systems.
Best Estimate of Energy Savings:
"Typical" Savings: 50%
Low and High Energy Savings: 25% to 70%
Energy Savings Reliability: 2 - Concept validated
Adding controls to intermittently occupied spaces will reduce energy use. If new lighting technology is required in order to employ the controls there will be an additional energy savings. How aggressive the operator wants to be with setbacks and light levels affect the amount of savings as do the technology used, the occupancy and daylight patterns. A rule of thumb in the industry says controls save an additional 50% of savings after the lighting technology changes are made.(Mutmansky, 2013 Pg 19).
The BPA C&I Lighting Calculator assumes a default reduction in operating time of 25% for the proposed system when lighting controls are provided. This number will be used in this analysis. If controls are not installed and operated correctly it is possible to have no savings and commissioning is recommended with any installation.
Luminaire-level lighting controls (LLLC) is an integrated lighting control approach combining local sensor inputs for dimming and daylighting control, occupancy sensors, and energy metering. Given distributed control at each luminaire, a central controller is unnecessary. Like central controls, LLLC offers the potential to provide 50% to 60% lighting energy savings (Navigant Consulting, 2014).
Energy Use of Emerging Technology:
2.4 kWh per square foot per year
Energy Use of an Emerging Technology is based upon the following algorithm.
Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
Potential number of units replaced by this technology:
NEEA estimates that there are 25 million fixtures installed in the commercial sector with only 102 thousand equipped with advanced local lighting control (Navigant Consulting, 2014). The total commercial sector square footage is 2.704 billion sf while the average interior lighting power density is 1.15 Watts per square foot. Average building occupancy is 79.3 hours/sf leading to a lighting system average annual energy use of 4.74 kWh/sf-year (NEEA, 2009), Table C-SC2) Note: the 6th Power Plan estimates a 20-year savings potential of 550 MWa for commercial sector lighting efficiency exclusive of new construction (Commercial Lighting Regional Strategy Development Group, 2013). This includes fixture and lamp replacement as well as increased use of advanced lighting controls.
Regional Technical Potential:
6.35 TWh per year
Regional Technical Potential of an Emerging Technology is calculated as follows:
Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)
Installed first cost per: square foot
Emerging Technology Unit Cost (Equipment Only): $1.50
Emerging Technology Installation Cost (Labor, Disposal, Etc.): $0.00
Baseline Technology Unit Cost (Equipment Only): $0.01
System costs vary according to the sources consulted. Ira Krepchin of E Source cited the cost for a total install of wireless controls as $4.00 to $6.75 per sf in his 9/21/08 Annual Forum presentation. Wired controls run $7.10 to $8.65 per sf, according to E Source. For comparison, Adura Technologies states that they can provide a turnkey installation for $1.50 to $2.00 per sf, about a third of E Source’s estimate of the cost for wireless controls. This cost advantage is expected to improve over time. (Note: Controls costs are rapidly declining and this data needs to be updated).
Based on the cost of a conventional localized control system recognized by Title 24 in California, which includes occupancy-based automatic control with photocell control in daylight zones and hi-low switching capability, the cost of installed equipment for the wireless, full dimming system (all ballasts were dimmable) was 3% less. The commissioning cost was 158% higher, but the annual energy cost was 60% of the baseline.
Simple payback, new construction (years): 7.0
Simple payback, retrofit (years): 7.1
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
The payback will depend on many factors, especially the utility rate schedule. A rate that favors daylight harvesting will show the best return. Payback will also be more dramatic if there are no current occupancy sensor controls in effect; if off and on are the only pre-existing choices, the space will be overlit if daylight is available or the occupants are not proactive in turning off unneeded lighting.
The 10 year LCC analysis by Daintree showed the partial dimming system achieved the lowest LCC right after installation. The fully dimmable system broke even in under a year and caught up to the partial dimming system at about 4 years. Further savings gave it the advantage throughout the rest of the study period (15 years).
Wireless lighting controls are part of the technology now referred to as Advanced Lighting Control Systems (ALCS). They use radio frequency (RF) signals to communicate between devices being controlled (including standard or dimming or bi-level ballasts) and the controller. Though dimming ballasts have historically imposed an energy penalty in their use, the demonstration project at the Alameda Water plant (see Prior Work, below) found the efficacy of the latest generation of dimming ballasts, at full light output, is within 2% of the efficacy of program start ballasts and 8% the efficacy of instant-start ballasts.
The communication allows for easy energy management data collection and components may report when they need attention. They are powered by long-life (10 yr.) battery power or environmental or operation energy such as solar or ambient light, temperature change, or physically pushing a button. They offer the same type of control options as hard-wired systems and more, with multiple zones controlled by a single controller. But no control wires need to be run, which makes is easier to locate components and reduces labor costs and occupant/operation disruption during installation. This wireless feature also makes this technology ideal for retrofits as well as new construction. Especially with new construction, space design plays an important role in how effective lighting and controls can be. Creating a layout to take the best advantage of daylight and choosing materials and finishes to enhance it can enlarge the effective daylit area.
Lighting can be controlled as individual fixtures or groups of fixtures in response to a variety of sensor inputs, including desktop remote controls at each occupant’s workstation, if desired. The systems tend to be scalable so they can be installed in part of a facility and expanded later. When operations change or space is reconfigured, controls are easy to reposition and re-program through web-based applications. Some systems include window shade control, making daylight harvesting more effective due to a combination of automation and easy control. Energy code requirements for auto off and demand response are easily addressed. Demand response can be implemented automatically or manually on a selective basis, and can integrate with a utility-level demand response system. Personal control of light levels has been shown in many studies to be popular with employees and results in energy savings. At least one company makes a special product for hospital bed light controls.
The communication range varies from product to product, generally falling within 30-150 feet depending on the product and obstructions. Some products offer more resistance than others, shortening the range. If necessary, repeaters can be added to increase the range. Several software platforms in use by different companies can be incorporated into mesh networks with more range and more complex loads, making it easy to reconfigure.
ALCS can be controlled via the web from a central operator, individual inputs, and occupancy and daylight sensors. The systems are also easily expandable so components can be added as desired to areas that did not initially require them.
The reporting features can provide information to the operators about energy use – a requirement of many high performance and utility programs – and failed equipment, which can facilitate timely repairs. Mesh networks allow the system to continue to operate by bypassing a failed unit, reducing the disruption it causes.
Standard practice for lighting control is either uncontrolled lighting energy use (manually switched or unswitched), occupancy sensor control, or control by an existing energy management/building automation system. It is not unusual to find existing systems disabled by occupants due to annoying or unsatisfactory performance.
The technology was developed at the Center for the Built Environment at the University of California, Berkeley and funded by the California Energy Commission’s Public Interest Energy Research program.
Wireless controls have been popular in residential applications for years before they started being used in commercial applications (which began around 2004 in demonstration projects).
Since the technology has proven its advantages, numerous manufacturers now offer products using several open source protocols, including ZigBee, Z-Wave, EnOcean, and some proprietary ones.
The Pacific Gas and Electric Company’s Emerging Technologies Program has published three case studies on the technology for industrial, commercial and government facilities focusing on energy savings. In at least one case, demand response controls were tested as well. These studies concluded that 50% savings are not difficult to achieve. The University of California has had similar success.
End User Drawbacks:
First costs are high, especially with the commissioning factor, so some incentives may help, as would referrals to competent commissioners if commissioning is not provided by the system manufacturer.
Potential obstacles include the lack of industry standards, which have limited EMS/building automation interoperability in the past, but this has improved in recent years. The Zigbee standard for metering is not directly translatable for commercial building control.
Some current control incentives require hard-wired equipment and may need revision to include wireless systems.
A recent study on advanced lighting control system for fluorescent systems and it's companion on fluorescent dimming ballasts done through the Sacramento Municipal Utility district found that as many as one third of the popular market dimming ballasts have an anomaly that could increase energy use where it would be expected to decrease and control strategies will need to be adjusted to preserve savings.
Finding a local contractor with experience installing the systems may be a problem, although the systems are not generally considered difficult to install. Commissioning is generally done by the manufacturer, so it is not an installer’s problem.
Another drawback is the need to replace transmitter batteries periodically on the systems that use them, but those with long-life batteries should not require attention for ten years.
Education will address any lack of understanding about how to specify a system, estimate costs, and design a new or reconfigured space to maximize daylight harvesting, light distribution and energy savings. Demonstrations for potential owners to visit, regional case study data, and trainings for installers could shorten the learning curve.
These systems add complexity to a lighting system. Once a system is selected, proper installation, commissioning, and documenting accurate information about how it works and what each part of the system does is critical to it performing as intended, and persisting if the current operator leaves. Some periodic re-commissioning may be needed and the operator needs to be able to make changes in operations as needed, especially to meet occupants needs so the system is not tampered with.
Operations and Maintenance Costs:
No information available.
A 10-year service life is anticipated, based on typical wired lighting automation control systems. Maintaining the system with periodic re-commissioning may be necessary to be sure it operates to the satisfaction of occupants. If re-commissioning is not done, the system may be disabled by occupants, reducing its effective life.
Other lighting control systems are wired technologies that require one or more dedicated control wires. Examples include:
• Powerline carrier (PLC), which uses higher‐frequency signals superimposed on the 50/60 Hertz (Hz) alternating current (AC) power signal and thus requires no additional wiring. An example of this is the Lumentalk powerline communication system deleloped by Lumenpulse and licensed to Lighting Services Inc (LSI) in November 2012.
• DALI, which connects addressable ballasts through a cabling system and is controlled through software utilizing photocells and occupancy sensors for inputs as well as scheduling. The digital ballast is always “on” to some degree.
• Relay switching panels that use vacancy sensors in all spaces and photocells where daylight is available, and ballasts that allow inboard/outboard switching for two light levels.
• Dimming panels that use dimming ballasts rather than switched ballasts in the daylight areas, along with vacancy sensors and photocells to control the light level.
• Hybrid systems that combine methods.
• Task-ambient lighting, with the task light on an occupancy sensor that is user-adjustable.
• Simple on/off occupancy-based controls are also in use, but code requirements are moving to bi-level controls in most areas and demand response options in some.
Reference and Citations:
Adoption of Light-Emitting Diodes in Common Applications
Department of Energy, Solid State Lighting Program, Building Technologies Office
Clanton & Associates ,
Wireless Lighting Control: A Life Cycle Cost Evaluation of Multiple Lighting Control Strategies
Clanton & Associates
Advanced Lighting Control – Is it Worth It?
Advanced Lighting Controls for Specifiers
Pacific Gas & Electric
Control Systems Make Daylighting Effective
Advanced Lighting Control System Assessment Final Report
San Diego Gas & Electric
Use of controls escalates in LED lighting despite lack of standards
Lumenpulse and Lighting Services Inc (LSI) Sign Licensing Agreement for Lumentalk technology
Wireless Lighting Controls Offer Flexibility And Cost Savings in Commercial Buildings
Lighting Controls Association
Lighting California’s Future: Integration of Lighting Controls with Utility Demand Response Signals
California Energy Commission
Advanced Lighting Controls for Demand Side Management (Energy Efficiency Assessment)
Pacific Gas and Electric
Photosensor Dimming: Solutions
Lighting Research Center
Wireless Lighting Controls Make Retrofits Practical
Public Interest Energy Research Program
Green Building Research Center,
University of California, Berkeley Wireless Lighting Controls Retrofit
Development of a Prototype Wireless Lighting Control System
Center for the Built Environment
Ace Hardware LED High-Bay Lighting and Controls Project
Pacific Gas and Electric Company
Study found 93% reduction in energy use with LEDs and occupancy and daylight controls installed over 400 Wmetal halide baseline.
Intel Advanced Lighting Controls Project
Sacramento Municipal Utility District
Describes anomalies with fluorescent dimming ballasts.
ADM Associates, Inc,
Fluorescent dimming Ballast study Report
Sacramento Municipal Utility District
If using dimming ballasts this study demonstrates some anomalies to be aware of.
Northwest Commercial Building Stock Assessment (CBSA): Final Report
Prepared by the CADMUS Group for the Northwest Energy Efficiency Alliance
Luminaire Level Lighting Controls Market Baseline
Northwest Energy Efficiency Alliance
Commercial Lighting Regional Strategy Development Group,
Northwest Regional Strategy for Commercial Lighting Energy Efficiency
Northwest Energy Efficiency Alliance