Recently, Lutron Electronics presented an enlightening (…sorry…) seminar in our office on lighting controls and their benefits in creating a more sustainable working environment.
The US accounts for roughly 4.4% of the world’s population according to the US Census Bureau (source), but we account for 20% of the world’s energy consumption. We spend nearly a fifth of that just to operate commercial buildings (so this statistic doesn’t even include the energy we spend on our cities’ infrastructure, our homes, or our industries). A full 28% of the energy used in commercial buildings is spent on lighting. Now if we do a little more math, based on the stereotypical 9-5 commercial work-day (which we know we're moving away from, but humor us for a minute), that means that our nation alone spends 1% of the entire world’s energy just to be able to see clearly during the day.
According to Lutron, controlling overall lighting levels through tuning and trimming – i.e., adjusting the maximum lighting output of each light fixture and bulb, as well as adjusting fixture output based on its location in a building (e.g., proximity to a window) – can reduce lighting energy use by up to 25%. Trimming can also extend the life of each bulb – all light sources suffer from lumen reduction over time, so light levels tuned and trimmed lower initially can be raised over time without the perception of light loss. Adding occupancy sensors and individual controls can decrease lighting energy usage even further.
Understandably, most clients need to know how this affects the bottom line. While installing trimmers, tuners, occupancy sensors, and individual controls will lead to energy cost savings over time, we understand that the start-up costs for the equipment can appear daunting. Consider, however, the secondary benefits: studies by the Rocky Mountain Institute (a non-profit dedicated to market-based sustainability solutions) show that profits from increasing employee productivity simply by providing individual lighting control can pay off the expense of installing those control systems in less than a year (source). In addition, every 3 watts in lighting energy-use savings decreases a building’s heating load enough to result in a 1 watt HVAC energy-use saving.
These statistics are by no means exhaustive, and as technology improves, so will the associated energy savings. Passive day-lighting and shading strategies can already significantly decrease building energy use, so imagine what else can be achieved with just a little extra commitment to installing active-sustainable features.
Have you had success in decreasing your energy costs through active (and passive) sustainability strategies? Have you specifically had success through tuning, trimming, and lighting control? Please let us know in the comments – we look forward to hearing from you.