Cut Energy Costs with Wireless Lighting Controls
- Lighting control systems reduce energy use, but are often difficult to install in retrofit situations.
- Wireless lighting controls are emerging as flexible, cost-effective alternatives.
- Radio-frequency wireless control devices are powered by batteries or energy harvesting.
Effective at reducing energy use, wired lighting control systems have been in use for many years. For existing buildings, however, wired systems can be time-consuming and disruptive to install. Radio-frequency (RF) wireless control technology is emerging as a flexible and cost-effective alternative for retrofit applications.
The benefits of wireless lighting controls
In RF wireless systems, control devices communicate through radio waves, eliminating the need for hard wiring. For both retrofits and new construction, wireless controls offer a number of potential advantages:
- Flexibility—control devices can be placed in almost any location without the limitations imposed by the need for hard-wiring.
- Scalability—controls can be applied to a single office space or an entire facility. Once a wireless network is established, devices can be moved and the system can be expanded without difficulty.
- Ease of installation—no need for a hard-wired infrastructure. Control devices can be installed without damaging the facility and disruption to business operations is minimal.
- Cost savings—quick and easy set-up requires less labor, reducing installation costs.
The benefits of wireless controls make them suitable for applications where additional wiring is too costly or difficult, such as parking garages and outdoor lighting.
How wireless controls work
The major components of a wireless lighting control system include relays, switches, sensors, and a central control interface. The communication range varies from 30 feet to more than 100 feet. Signals often penetrate glass, wood, and plaster but not through certain types of metal.
Wireless control devices are powered by batteries or through energy harvesting, which captures and uses energy from the surrounding environment. Typical examples in lighting control systems include the motion from pushing a light switch or inserting a hotel key card. Sensors are powered by surrounding light or changes in temperature. Energy harvesting eliminates the need to change batteries.
In its simplest form, wireless controls include light switches embedded with RF receivers that communicate with relays attached to light fixtures. Adding sensors helps to reduce energy costs and improve the work atmosphere. Wireless photo sensors or occupancy sensors turn lights off in unoccupied spaces or dim lights to take advantage of natural lighting. A software interface controls the system from a central point, such as a computer or smart phone.
In order for RF wireless control devices to integrate with other control systems, they must use the same communication standard or protocol. ZigBee (IEEE 802.15.4) is an open-source RF wireless communication standard. Many wireless device manufacturers have developed proprietary standards they share with their suppliers and manufacturing partners. Wireless systems can be standalone units or they can supplement an existing lighting control operation or building automation system.
Wireless controls in action
The University of California, Santa Barbara, retrofitted 10 lighting fixtures that operate 24 hours per day, 365 days per year, with wireless controls. The goal of the project was to demonstrate the energy-saving benefits of daylighting and occupancy control. The need to reconfigure existing wiring would have made such a solution too expensive. The wireless control system was cost effective to install and reduced lighting energy use by 33 percent, resulting in annual cost savings of more than $600.
Lighting controls are an effective strategy for eliminating energy waste and reducing operating costs. However, hard-wired systems are often too expensive to install in existing buildings and many outdoor applications. It is likely that wireless systems will continue to emerge as cost-effective alternatives.