The University of British Columbia in Canada is developing a new passive solar technology that could revolutionize commercial building design. Imagine a building design in which incident natural light could be collected and transferred from the building’s facade to interior rooms using only mirrors and tunnels. This would replace the energy-intensive fluorescent lights that typically illuminate the world’s office buildings. Called a Solar Canopy Illumination System (SCIS), this technology consists of two basic components. First, a solar canopy is integrated into the building exterior at the ceiling level of each building story. The canopy collects sunlight, concentrates it with an array of well-placed mirrors and guides it into the system’s second component. The Dual Function Prism Light Guide acts as a tunnel for the sunlight. Its reflective interior uses some handy concentrated solar power techniques to ensure that light will travel deep into the room with enough intensity to evenly cast natural light into the rooms below. The University of British Columbia points out six major benefits of its unique passive solar lighting technology:
- Provides useful daylight as much as 20 meters into the interior of a building.
- Reduces energy consumption for standard commercial lighting by at least 25 percent.
- Replaces 75 percent of electric lighting on any day where the sun shines within six “core hours.”
- Outperforms the efficiency of solar photovoltaic lighting by a 7:1 ratio.
- Integrates easily into standard commercial building designs.
- Only core lighting technology to be cost-effective through energy savings.
Those are bold statements for a new technology. In case you’re wondering how a passive solar technology could reliably replace fluorescent lighting in commercial buildings around the world, it won’t… completely. SCIS is a hybrid system. Housed within the Prism Light Guide is efficient, back-up fluorescent lighting and simple actuators that will kick in the back-up system when it is cloudy or the sun is otherwise obscured.
The system can also be designed as a hybrid of passive and active solar technologies. Because 100 percent of the incident light striking the Solar Canopy is not reflected into the building as natural lighting, solar power panels can be integrated into the canopies to generate electricity for the building as well.
Photo Credit: Tom Brown