Hybrid-Solar Benefits

Hybrid Solar Lighting Benefits

Nearly all living creatures, including human beings, have been designed to function and thrive in natural light. Therefore, it should be no surprise that scientists have identified powerful biological and psychological effects that are strongly dependent on the presence of natural light. With Hybrid Solar Lighting, it is now possible to control and maximize these effects to increase sales, increase productivity, increase wellness, etc. while also reducing energy consumption.

This page is dedicated to informing the reader about the many benefits of natural lighting. Where appropriate, the reader is directed to reputable references that provide more detailed explanations of the mechanisms behind specific benefits. Because there is still much being learned about these complex processes, the information provided in this page will be updated as often as possible. Please check back frequently for the latest information.

Increased Sales with Hybrid Solar Lighting

It has long been believed that retailers that incorporate natural lighting into their buildings have higher sales than retailers who do not. In 1999, the California Board for Energy Efficiency put this belief to the test by commissioning a scientific study of 108 nearly identical stores, two thirds with natural lighting from skylights and one third without natural lighting. The study revealed, with 99% statistical certainty, that the stores with natural lighting sold 40% more merchandise than the stores without (click here for the full report). Surveyed customers indicated that, although they were unaware of the skylights, they perceived the stores with natural lighting to be cleaner, more spacious, and more inviting (factors that may have contributed to their increased buying). This finding was independently confirmed by additional studies (conducted by various retailers) and follow on studies funded by the California Energy Commission (which verified the trend between daylighting and increased sales with sales increasing 2.4% for every 100 hours of daylighting).

Unfortunately, the daylighting technology that was tested in many of these studies was skylights, which do not make maximum use of the sunlight and are limited to ambient lighting (i.e. they cannot be used for highly directional, product lighting). One of the advantages of the Hybrid Solar Lighting technology is that it allows retailers to maximize the benefits of natural lighting for increasing sales by providing a flexible source of natural light that can be used for ambient lighting AND directional lighting. In addition, the Hybrid Solar Lighting system allows sunlight to be captured efficiently throughout the entire day and distributes that light to the exact location in the store where it is needed most. The intensity and distribution of the collected sunlight is highly controllable and, therefore, can be incorporated without unwanted side-effects (such as "washing" out product displays, a common problem with skylights that can actually reduce sales). Given this increased capability and the prior data on the benefits of natural lighting, Hybrid Solar Lighting is expected to significantly improve retailer sales, possibly by even more than 40%! Studies are underway to verify and quantify this potential benefit.

Increased Productivity with Hybrid Solar Lighting

Productivity is a particularly difficult quantity to measure. Unlike sales, which can be quickly tallied, the productivity of a work force, and the metric that best represents that productivity, is going to be dependent on a number of complex variables. Despite these obstacles, there have been a number of studies conducted that attempt to do just that. Comparing the productivity of occupants in buildings with natural lighting against those without, several studies are have produced interesting results. Each reveal a positive correlation between natural lighting and increased productivity.

Studies on Student Productivity

In 1999, the California Board for Energy Efficiency commissioned a study into the affect of daylight on student learning rates. Elementary schools in the Capistrano school district in Orange County, California were monitored and test scores evaluated over a one year period. Students in schools with natural lighting from skylights were measured to progress 20% faster on math tests and 26% faster on reading tests than students in schools without natural lighting (click here for the full report). What is particularly interesting is that the findings showed that all skylight designs were not equal. Some skylight designs actually performed significantly better than others. The report states on page 64:

"The systems that performed well... generally had the following characteristics:

They provided wide, diffuse distribution of daylight, by using diffusing lenses and/or diffusing louvers and wells.
They prevented direct penetration of sunlight into the classrooms
They allowed the teacher direct control of the amount of daylight illumination through the use of louvers or blinds."

Interestingly, Hybrid Solar Lighting provides exactly the same type of distributed, controlled lighting that the study identified as being valuable for increasing student learning rates. Additional studies have been performed that result in similar conclusions concerning daylighting and student learning. More can be learned about the connection between daylighting and student productivity from The Jordan Institute (a science-based, non-advocacy, non-profit organization). The Jordan Institute offers a fact sheet highlighting many of the benefits of daylighting to schools.

Increased Wellness with Hybrid Solar Lighting

The effects of natural light on the regulation of key biological processes has been known and documented for many years. As more time is spent under artificial lighting, the regulation of these processes can become disrupted and affect wellness. Studies have estimated that 5-20% of the U.S. population now suffers from Seasonal Affective Disorder (SAD), a serious disorder that causes symptoms of depression that occur during the winter months and subside during the spring and summer months. Depending on the severity of the disorder, SAD sufferers may display one or more of the following symptoms:

Sleep Disorders
Overeating
Depression
Anxiety
Family/Social Problems
Lethargy
Joint/Stomach Pain

The cause of this disorder is known to be linked to a disruption in the natural light cycles that humans experience with the changing seasons. By spending a significant amount of the day under artificial lighting, a building occupant can become disconnected from the seasonal and daily variations in natural lighting levels that regulate the body's circadian rhythms. This eventually results in a disruption in the production of melatonin hormone levels from the pineal gland. "Bright light" therapy is the recommended treatment and involves exposure to intense lights for a prescribed period of time each day (to stimulate or reset the production of the pineal gland).

Research has shown that the lack of natural daylighting in buildings plays an important role in the occurrence of SAD. For the first time, the Hybrid Solar Lighting technology provides building owners with a convenient method of delivering the therapeutic properties of natural light to their occupants without the structural constraints and architectural drawbacks associated with conventional daylighting. Existing buildings that are not properly oriented or constructed for daylighting can be easily retrofitted with the Hybrid Solar Lighting technology to provide continuous exposure to sunlight throughout the year. The increase in employee wellness can result in increased worker productivity, reduced absentee-ism, and improvements in employee moods and interactions.

To learn more about the connection between SAD and natural lighting, please read the National Mental Health Association's fact sheet on this disorder.

Reduced Energy Costs with Hybrid Solar Lighting

Lighting consumes more electric energy than any other building end-use, accounting for a third of all electricity consumed for commercial use in the United States. Ironically, much of this lighting energy is consumed during peak daylight hours when sunlight is readily available. The ability to capture and utilize this sunlight for interior building lighting provides a real opportunity for significantly reducing energy consumption in the United States.

On a sunny day, one Hybrid Solar Lighting system will deliver 50,000 lumens of sunlight, or the equivalent of 55 60W incandescent lamps. For buildings in the Nation's sunbelt that use incandescent lamps, which have a luminous efficacy of 15-20 lumens/watt, this can result in two forms of energy savings. First, there is an energy savings of approximately 8000 kWh per year due to the reduced lighting needs. Second, there is an energy savings resulting from the buildings reduced cooling load. Because the Hybrid Solar Lighting system delivers light with little to no infrared component, there is very little waste heat. Depending on the cooling technology utilized, this can result in an additional energy savings of as much as 8000 kWh per year, or a total energy savings of 16,000 kWh per year.

The cost savings associated with this energy reduction will vary depending on local utility rates. As an example, for areas with high utility rates, such as Hawaii or California, the cost per kWh can be as high as $0.10 per kWh (and in some places even more!). Therefore, over a ten year period, a Hybrid Solar Lighting system, working with incandescent lamps, can save a building occupant in these locations $16,000 per unit. For large floor-spaces of 100,000 to 200,000 sq. ft., this translates into $1.6M to $3.2M of energy cost savings over a ten year period.

"...large floor-spaces of 100,000 to 200,000 sq. ft., this translates into $1.6M to $3.2M of energy cost savings over a ten year period."