Using daylight to replace electric lighting is a practice that involves using an integrated design process that takes into account many factors.  Initial considerations are the geographic region and climate, the orientation of the building in relation to the sun and the proposed or existing use of the building.  The designer or energy consultant also needs to consider window to wall and skylight to ceiling ratios, required lighting levels in various spaces, contrast and reduction in glare. Daylighting is a concept that can be approached in a number of ways, offering a variety of solutions for energy-conscious business owners.

What you may not realize is that many electric lights in commercial buildings generate an inordinate amount of heat, which can result in not only using energy to power the lighting but increased energy usage to cool the building.  Implementing a daylighting strategy can often result in decreased cooling costs and can allow the building owner or designer to put more efficient lighting and HVAC equipment in place, all of which may help defray the costs of daylighting improvements. 

Properly placed and sized windows are an important part of a daylighting strategy, as well as use of low transmittance glass and various shading devices.  The idea is to allow as much natural light as possible while reducing glare.  Creative window placements such as a row of clerestory windows high on the wall offers an appealing and effective natural glow.  In many buildings, windows provide sufficient light during the day, reducing the need for artificial lighting to evening hours.

Skylights also provide a boost in natural light and a substantial energy savings in commercial buildings.  Skylights are particularly effective in areas that are considered “interior” - further from the perimeter windows and in hallways or enclosed spaces.  Skylights provide surprisingly high illumination levels and many studies have proven to also elevate the mood and performance of building occupants.

Options for energy-conscious business owners include passive skylights and “smart”- or active  skylights.  Smart skylights use mirrors and GPS controlled sun tracking devices to follow the sun and drive light into the building.  Some types of smart skylights promise to provide up to 3 times the light of a passive skylight, allowing artificial lighting to be turned off for up to 10 hours a day.  Marky Moore, CEO of energy and tax consulting firm, Capital Review Group in Phoenix, Arizona explains, “What CRG has found is that when coupled with a new lighting system, smart skylights do actually improve the simple pay back period of the lighting system and reduce operating and O&M costs.  Even more importantly, smart skylights improve production and the quality of work, reduce absenteeism and provide for a more pleasurable work environment.”

In addition to energy savings, implementing a strategy to incorporate daylighting or skylights may also result in tax savings for building owners.  The Energy Policy Act of 2005 includes a tax deduction for investments in “energy-efficient commercial building property” designed to significantly reduce the heating, cooling, water heating, and interior lighting energy cost of new or existing commercial buildings.  This energy-efficient commercial building property must be placed into service between January 1, 2006 and December 31, 2013.

To qualify for the full deduction, a building owner or tenant must make investments designed to reduce energy costs by 50% or more.  A partial deduction of $.60 per square foot is available for investments in one of three subsystems – lighting, heating and cooling; or building envelope – designed to reduce energy costs by 16 2/3% (one third of the 50% requirement).  Moore says, “Skylights as part of a lighting system will reduce operating costs, improve O&M expenses, allow for greater longevity in the lighting system and will most often, when implemented correctly, qualify under the Interim Lighting Rule for Section 179d deductions.” 

Evaluating a building’s lighting system may initially seem like a minor upgrade, but may actually illuminate major energy savings, improved working conditions and significant tax deductions.