Digital Systems Blog

Daylight Harvesting is a Valuable Lighting Control Strategy often Overlooked

startup-photos.jpgWinter is coming!  And with it shorter days and an increased need for more artificial light. This in turn is prompting many organizations to consider new lighting control strategies to reduce energy consumption without negatively impacting their tenants or workers.  One smart lighting control strategy that we find often overlooked or perhaps misunderstood is daylight harvesting.  So let’s take a look at what it is and how it can be beneficial.  

We’re all familiar with the value of natural lighting and its positive effects on mood, productivity, and learning.  As an example, a study from the Lighting Research Center (LRC), in Troy, N.Y., reported that daylight environments increase occupant productivity and comfort.  Natural light provides health and workplace benefits in addition to environmental and economic advantages.  

The Fundamentals of Daylighting and Daylight Harvesting

Green building practices and standards that aim to reduce energy consumption, such as the U.S. Green Building Council’s (USGBC) LEED rating system, have spearheaded the concept of daylighting--the illumination of spaces with natural light by adding more windows, skylights and reflective surfaces such as glass internal walls. Additional daylighting considerations include the building’s orientation to the sun, external obstructions, time of day, time of year, weather and more. The U.S. Department of Energy’s (DOE) Federal Energy Management Program reports that daylighting can significantly cut lighting energy use for building interiors by as much as one-third through the optimal use of daylighting strategies. Daylight Harvesting takes the energy reduction and cost savings benefits of daylighting to the next level.  

Daylight Harvesting enables a building to collect and utilize natural daylight and distribute it effectively into the building. Automated lighting control systems measure the amount of natural light in a space using light sensors, and dim or switch off artificial light levels when sufficient ambient light is present. The light sensors enable a consistent lighting level and the control system uses only as much artificial light as necessary thus reducing energy consumption and providing an optimum level of light for the occupant. For example, as the amount of natural light increases in the morning, the level of artificial lighting is reduced. The opposite then follows; as the day gets darker, the level of artificial lighting increases as the level of daylight reduces. Daylight Harvesting manages the artificial lighting in a building to ensure space is not over- or under-lit, which enables employees to work productively in a consistent and optimal level of light.   

Where is Daylight Harvesting Impactful?

Daylight harvesting can be used in nearly any type of facility where the lights are on most of the time and daylight is plentiful. Spaces that boast natural light such as corridors with skylights or offices and cubicles that are near windows are likely perfect spaces for implementing a daylight harvesting control strategy.  

In addition, those spaces that need only moderate levels of light such as hallways and corridors, can gain some benefit from daylight harvesting. If daylight escapes through private offices into hallways, it can be leveraged and hallway lights can be further dimmed.  

Energy Saving with Quick ROI

Because artificial light is automatically dimmed or switched off when sufficient ambient light is present, a business’s carbon footprint can be reduced by implementing daylight harvesting.  If the level of electrical lighting is decreased during peak hours, a lower level of energy is needed to light up the space. During the day, artificial lighting can be kept low providing significant energy savings.  

Electricity costs are highest during peak periods of usage which typically occur during the daytime. A daylight harvesting strategy implemented during peak hours can have a great impact on the demand portion of your electricity bill by reducing usage levels. In addition to keeping your utility costs down, it can help reduce the need for a utility company to build peak load power plants that are primarily dependent on fossil fuel.   

The cost of implementing daylight harvesting can be rapidly equalized. The more natural light your space receives, the higher your return on investment.  The closer indoor lighting mirrors nature, the more beneficial to occupant productivity, health and wellness, and your bottom line. And, daylight harvesting further leverages the investment made in all those beautiful windows and skylights.  

Learn how a progressive manufacturer used daylight harvesting as part of their smart lighting strategy to reap huge energy savings by downloading the case study below.

smart lighting

Topics: Lighting Controls, Energy Efficiency