Growing up, we were probably all told countless times to switch off the lights when we left a room—likely also accompanied by a reminder that “money doesn’t grow on trees.” Even if those lessons stuck, as adults we find ourselves in plenty of situations where our control over the lights isn’t quite so simple. In office, hospitality, retail, or other public settings, light gets wasted due to more than just leaving a lamp on. In this month’s blog, we explore some key causes of wasted light and four solutions to reducing it for a more sustainable space.
What is wasted light?
In a nutshell, Jeremy Snyder (Director of Energy Programs at Rensselaer Polytechnic Institute’s Lighting Research Center) explains, “Light is wasted any time a person doesn’t need it,” going on to clarify “either because the space is unoccupied or because more electric lighting is being provided than is needed.” Whether people spend a long time or just a few moments in a building, they may not recognize that a space is overlit, even if they feel the effects.
Wasted light creates a number of problems, ranging from light pollution to over-illumination to unnecessary energy usage (and costs). Outdoor lights directed upwards or indoor lights shining out a window might not be immediately noticeable as a problem, but at best these set-ups are just sending light out where it is not needed, but at worst, this wasted light can disrupt circadian rhythms, wildlife behavior, and the health of ecosystems.
Over-illumination can cause eye strain, fatigue, and stress for those who spend extended amounts of time in a space. It can even disrupt circadian rhythms, all while wasting energy producing more light than what is needed. It creates inefficiencies, increasing facility costs in terms of energy consumption, labor, and maintenance. Upfront costs are inflated if too many luminaires are installed from the start. All to produce more light than the users need.
So how can we identify and reduce wasted light for a more sustainable environment?
Investigate your space
First off, it is important to get a real sense of what you are illuminating, and whether your lighting is really getting the job done efficiently and effectively. Determining areas that do not require as much illumination can help reduce wasted light. Look for lighting that may not be necessary given the additional light from computer screens or natural light from windows. Or low traffic areas that are illuminated 24/7. In public spaces, uniform lighting has been the standard, avoiding the need to switch lights on or off for different tasks, but smart technologies can now help us adapt to task needs more smoothly. Looking at what different activities take place can help you determine what type of lighting can best serve these different purposes, as you identify sources of (potentially) wasted light.
Thoughtful lighting design
The next step after analysis is building on your findings in designing a lighting scheme adapted to your needs. Determining the best way to light a building effectively requires knowledge of a number of different factors: from technical specs to aesthetics to a solid understanding of how people will use the space (and what kind of lighting will best support those uses). This is why working with a lighting designer is so critical: they will bring a real breadth of knowledge to the table that can help reduce over-illumination and create a comfortable space for the activities at hand.
Understanding the needs of who uses a space is critical. We have looked previously at the idea of human-centric lighting. Along with an understanding of how a space will be used, it is important to consider how users will likely behave in a space. When a cleaning crew comes through at the end of the day, are they going to have the time or patience to seek out individual switches, or do they need everything on so they can do their job fast? Is a team going to remember to switch off those conference room lights when they are finished? Occupancy sensors can play an important role in helping to manage wasted light, which brings us to…
Smart Controls
When it comes to keeping track of when the lights need to be on, smart controls can remove the risk of human error and help keep wasted light to a minimum. Intelligent lighting involves a series of networked systems that relay back to a primary lighting control device. They include occupancy sensors, photocells, time sweeps, light control switches/dimmers, and touchscreens. The system’s main control typically occurs at a central computer. However, remote user interfaces can also be made available in order to offer more flexible control over lighting needs.
A well-designed lighting control system can reduce energy consumption by providing the appropriate light when needed and keep unused lights off when a space is not being used. The result is increased efficiency and maximized savings.
Effective daylight harvesting
Another way to avoid wasted light and over-illumination lies in the use of daylight harvesting, which comes from the need to reduce energy consumption. We cannot leave all the work up to that sunlight streaming in through the windows, but a carefully designed lighting scheme can harness daylight as much as possible, while providing backup lighting for cloudy days or nighttime needs. The key is to avoid over-illuminating a space by adapting to the natural light available.
Smart control systems described above support this effort by offsetting the amount of artificial lighting needed alongside natural light in order to properly illuminate a space. Controls can provide automatic adjustments to daylight levels while maintaining a target level of light in a space over the course of the day. This ensures that a space is not over-lit, or under-lit, and the occupants of the space are provided consistent and optimal levels of light.
Upcoming research into luminous efficacy will provide even more insight into how much and what kinds of light are truly useful to the human eye and guide future innovations in lighting design. We look forward to new technological advances that make it even easier to avoid wasting light. Definitely a more sustainable solution than waiting for that money tree to grow.
At CharterSills, we believe that when lighting is designed correctly, it can add dimension to the simplest of spaces. Lighting can turn an ordinary space into a work of art. Whatever design challenges clients present, CharterSills responds with a solution that exceeds their expectations. Contact us today at (312) 759-5909 or by email at info@chartersills.com.