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.

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.

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.