4 Ways Solar Tracking Skylights Differ From Traditional Skylights
By Torrin Greathouse | January 14, 2016
In the last few decades, skylight technology has undergone a vast revolution. The industry has transitioned from traditional, passive skylight design to more efficient active designs—such as solar tracking skylights.
Many consumers are hesitant to adopt skylights, because some poorly designed traditional skylights can actually increase energy costs. What they do not realize is that there are four key differences between traditional skylight and their solar tracking cousins which help to avoid these increased costs.
Heat Gain & Loss
One area where traditional skylights are severely lacking is in their ability to protect your building envelope. Because they allow sunlight straight into the building, often without diffuser lenses or low emissivity coatings, the solar radiation can increase indoor temperatures, while their lack of proper insulation allows heat to escape from inside. These two elements are measured by solar heat gain coefficient (SHGC) and U-Value. A side by side comparison of traditional and solar tracking skylights shows that solar tracking systems are 23% more efficient at preventing heat gain and 36% more efficient at preventing heat loss than traditional skylights.
Cheaper traditional daylighting systems often lack of proper weatherproofing. Ice dams and leaking are two issues they face, both of which can cause major structural damage if they go unchecked. Solar tracking systems avoid this by utilizing a well insulated, weatherproof design which minimizes the harmful effects of harsh weather patterns.
Hours of Light Provided
The goal of daylighting is to bring natural light inside of your building for as many hours as possible each day in order to reduce lighting costs and to provide a greater quality of light. Consider then that typical traditional skylights only provide between 4-6 hours per day of natural lighting. The hours of light provided is the key dividing factor between traditional and solar tracking skylights. Solar tracking systems combine GPS and solar power to follow the sun on its course through the sky, using a mirror array to direct sunlight inside for up to 10+ hours per day—nearly twice as long as their predecessors.
Roof Area Requirement
Another key difference between traditional skylights and their solar tracking cousins is their roof area requirement. The number of skylights required to effectively light a facility can differ wildly; solar tracking skylights require significantly less roof space to provide the same level of light as most traditional designs. Older flat skylights can take up to 10% of your roof space to provide adequate light, reducing room for HVAC units and other sustainable technologies such as solar panels and wind turbines. On the other hand, solar tracking systems require as little as 1-2% of your roof area to provide the same level of light.