Looking to improve energy efficiency? Lighting controls are a good place to start. A Cleantech Approach (CTA) May 2010 research and analysis report, “Lighting Controls: Savings, Solutions, Payback and Vendor Profiles,” concludes that lighting control solutions for commercial offices can reduce electricity consumption by 35 percent to 55 percent. However, since payback periods on the initial investment can range from three to 11 years, those involved in these decisions should choose carefully.
Effective management of lighting is fundamental to a sound energy efficiency strategy. It's a smart approach given 20 percent of commercial buildings' overall energy expenses and 38 percent of their electricity expenses go to lighting. With an eye toward reducing electricity consumption associated with lighting, CTA's findings indicate that the two most impactful technologies include lighting controls and next-generation lighting such as LEDs. Of the two, CTA recommends lighting controls as the better first step toward reducing energy consumption, given that these solutions carry lower technology risk and less up-front cost than next-generation technologies.
LIGHTING CONTROLS With lighting controls, businesses can easily control the behavior of their lighting assets (i.e., when lights turn on and off, or how and when lights dim) to eliminate wasted light and excess electricity consumption, while meeting employee needs for their work environment.
There are two critical factors to consider when choosing a lighting-control solution: explore the potential payback as well as each vendor's unique technological approach. CTA's research found that, often, not enough time is spent examining how quickly a given lighting-control solution will allow purchasers to recoup their initial investment. Accordingly, undertake a thoughtful examination of a building's or space's energy-use profile. Given the age of and general technology employed in today's commercial office buildings, it is likely that there are opportunities to reduce energy use with simple strategies such as daylighting, occupancy control, and scheduling. This examination will yield a general cost basis from which a pay-back period can be calculated.
CTA used a proprietary approach to examine the cost of lighting control solutions, determine the range of potential cost-saving opportunities, and calculate the resulting payback periods associated with the adoption of lighting control technology. The findings indicate:
CTA also examined five control strategies that lead to electricity savings, all of which should be considered as part of a control solution. These five leading control strategies are:
FRAMEWORK FOR UNDERSTANDING VENDORS' APPROACHES The other important consideration is to evaluate each vendor's technological approach. Certain solutions are optimized for certain environments; be sure that you select a solution that is optimized for yours.
Lighting control solutions vendors (and brands) profiled in CTA's May 2010 report included: Acuity Brands (Synergy Lighting Controls, SensorSwitch, Lighting Control & Design); Adura Technologies; Cooper Controls; Delmatic; Encelium; EnOcean; Leviton Manufacturing; Lumenergi; Lutron; Philips (Dynalite, Lightolier Controls); Schneider Electric; Universal Lighting Technologies; and WattStopper. (But CTA does not recommend vendors nor do they endorse a particular strategy for lighting controls.)
While all of these vendors employ sophisticated, centralized, software-based approaches, they often differ on the framework through which they deliver functionality. The chief differentiators among these solutions are their respective communication method and control intelligence dispersal.
COMMUNICATION METHOD This refers to the connection between elements in the network (lighting fixtures, sensors, and switches) and an aggregation device, and can be wired or wireless. The aggregation device collects the data and brokers communications between the peripheral devices and the central management console, where the lighting network is monitored and control parameters are set. Wired connections require the data to be transmitted over low-voltage wiring. Wireless connections can be achieved in one of two manners: data sent wirelessly (usually using ZigBee or EnOcean protocols) to an aggregation device or data sent over the existing powerline network with no low-voltage wiring.