Calculating Energy Savings

Energy savings due to installing lighting controls can be challenging to predict since spaces and lighting needs vary from site to site and throughout the year. Energy savings from controls achieve power savings through dimming and shutoff based on varying inputs like daylight availability and occupant utilization. Further, lighting controls with dimming capability create light level changes based on user preference and other factors.

While lighting control savings can be estimated for a given project based on application data, it is useful to evaluate various lighting control strategies based on average energy savings. Knowing an average is also useful for benchmarking predictions and results.
Enter the Lawrence Berkeley National Laboratory (LBNL), which analyzed 240 energy savings estimates from 88 case studies and papers. Using filters to zero in on lighting energy savings produced by lighting controls in actual field installations, the researchers developed best estimates for average lighting energy savings and published the results in an industry paper. These estimates ranged from 24-42% and covered occupancy sensing, personal and institutional tuning, daylight harvesting and the combination of multiple control strategies, as shown below.
The LBNL study demonstrates that advanced lighting control strategies typically save significant amounts of energy, and provide guidance for average savings.

LBNL best estimates of average lighting energy savings for various lighting control strategies.
1. Occupancy sensors that change lighting automatically can reduce energy consumption by up to 24%. 
Acuity’s Sensor Switch® is an industry leader in developing occupancy sensors and control switches and has the widest array of sensors offered from any manufacturer. Their controls feature small motion detection, relay circuit protection and passive dual technology (PIR / Microphonics™) that can literally "See & Hear" into areas with obstructions.
2. Institutional tuning of light levels (using high end limits on the lighting to deliver the right amount of light) by dimming controls reduced energy consumption by up to 36% on average.
Dimming systems from  Acuity’s Synergy® Lighting Control, SensorSwitch’s nLight® and LC&D enable smooth full-range dimming on fluorescent, LED, low voltage and halogen luminaires. These systems can be tailored for office, education, retail and institutional spaces.
3. Using daylight harvesting can reduce energy consumption by up to 28%.
Daylight levels are detected by photosensors which can then tell the controls how much to reduce electric light while still delivering excellent illumination in the space. Acuity Brands can integrate a full range of daylight harvesting strategies with the LC&D, Synergy or nLight® controls systems plus Sunoptics® LightFlex™ daylighting delivery system to bring sunlight deeper into the space for additional savings. This allows the user to control how much daylight or electric light is being used to illuminate a space, or they can have the footcandle levels pre-set and let the system do the adjusting for them.
4. Combining any of the multiple strategies reduces energy consumption by 38%.
Acuity Brands makes combining control solutions with energy-efficient and smart lighting easy with an extensive portfolio of products – also Acuity solutions are manufactured and supported by one company.

How Acuity Brands Can Help

Acuity Brands leads the industry in helping make these savings a reality with the most extensive product portfolio in the industry. The previously mentioned products and solutions integrate seamlessly with each another, providing the end user with a complete lighting solution that enhances their environment, reduces energy usage and saves them money.