Advanced lighting control devices and systems can be used to reduce ongoing costs for the owner and thereby increase profitability and competitiveness. According to the New Buildings Institute, lighting controls can reduce lighting energy consumption by 50% in existing buildings and by at least 35% in new construction.

Lighting Energy: Controls can reduce the amount of power drawn by the lighting system during operation and also the number of operating hours, thereby reducing utility energy charges.

Lighting Demand: Controls can reduce the amount of power drawn by the lighting system, reducing utility demand charges—particularly during peak demand periods, when demand charges are highest.

These cost savings can produce a short payback and a high rate of return for the investment in the new controls. In new construction, the rate of return is often higher because only the premium, not the total installed cost, will be recouped before positive cash flow is realized.

OMC Lighting Control Designs for Energy Saving

Occupancy Sensors: Occupancy sensors are the most common lighting control used in buildings today. Two technologies dominate: infrared and ultrasonic. Infrared sensors detect temperature changes in a room, and work well where the entire room is within the sensor’s field of view. Ultrasonic sensors use high frequency sound, much like bats do, to detect motion (even around corners). Dual-technology sensors use both methods, increasing accuracy and flexibility, but at a higher price. Even though lamp running life may be somewhat shortened by increased switching due to occupancy sensors, the overall chronological life of lamps is usually extended by the reduced daily burn hours.

Time Scheduling: Large open areas work well with simple time scheduling – automatic switching at fixed hours of the day. Overrides allow users to turn on the lights if scheduled to be off (using wall switches). Time scheduling can be accomplished with the in-built system time clocks or more sophisticated computer controls. To save more energy, time scheduling systems can be designed so that lights are turned on manually rather than automatically at the beginning of the day, but are turned off automatically when the villa will not be occupied.

Bi-level Switching: Some people prefer lower overhead lighting levels (especially if daylight is available). Lower light levels are often preferred for computer use, meetings or tasks that are not visually demanding. Bi-level switching can provide simple manual control. For example, in a typical 3-lamp fluorescent fixture, the outer lamps are switched separately from the middle lamp, allowing the user to switch on one, two, or all three lamps. This low-cost measure is a minimum control requirement in some state energy codes, and can provide a simple means of load-shedding during peak hours if the bi-level lighting circuits are remotely controllable.

Dimming: In rooms where different light levels are needed at different times, such as living rooms, the use of manually-operated dimming controls is a common solution. These controls are wall-mounted and reduce energy consumption as they only distribute power required for the light level required and not total power as a conventional resister dimmer.

Light Level Sensors - Automatic Daylight Dimming/on/off: Automatic daylight dimming, or “day lighting,” uses a light sensor to measure the amount of illumination in a space. Then light output from dimming ballast is adjusted to maintain the desired level of illumination. The combination of daylight dimming with appropriate task lighting is often very effective. Corridors and open cubicles near windows, particularly those with task lighting, are good candidates for day lighting controls. Rooms not often used with windows can also be equipped with individual daylight sensors. Initial commissioning and calibration of light sensors and controls is critical for effective day lighting, however; poorly calibrated daylight sensors can result in little or no savings, and may annoy occupants.

Demand Limiting: During peak demand periods utilities often charge significantly higher prices for electricity. Remote operation of dimming ballasts or bi-level switching helps operators to respond to price signals or utility requests to shed load to help avoid power outages. (Not applicable to the UAE)

Table 1,1 Operating Cost Comparison @ Open Area, 1000 sq. ft

Note:
a) Prices calculated using DEWA kWh unit costs effective as of 1st March 2008

Ecology: Electricity savings go hand-in-hand with ecological benefits. Fuel (typically coal) is burned to produce electricity. Burning fuel produces airborne pollutants such as NO2 and SO2, which cause smog, and carbon dioxide (CO2), which contributes to global warming. In addition, saving fuel reduces the embodied energy needed to get that fuel to the power plant.