UBC Solar Illumination System
Alexander Rosemann
The University of British Columbia
Overview
• Goal of the project
• Design of the solar canopy and light guides
• Designing a portable test facility
• Measurement results
• Cost benefit analysis
• Next steps
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Goal of the Project
• Goal: To establish feasibility and cost-effectiveness of
core daylighting for standard multi-floor buildings
• Not expecting to address every type of building, but
system could be used in many standard office towers
• Led by the UBC Structured Surface Physics
Laboratory with key collaborations in Canada and
worldwide:
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Korea Institute of Energy Research, Taejon, Korea
Natural Resources Canada (NRCan), Ottawa,
British Columbia Institute of Technology, Vancouver
BC Hydro / Power Smart, Vancouver
Solar Canopy Illumination System
Solar canopies mounted on the south-facing wall of a
multi-storey building guide sunlight into prism light guides
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Benefits of Hybridization
Energy saving features:
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Provides shade for the windows
Collected heat can be conducted inside or rejected
Protection for low-cost photovoltaic cells
Dual-function light guide provides electric lighting
Hybridized features enable a cost-effective system.
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Design of the Solar Canopy System
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Dual-Function Prism Light Guide
Designing a Portable Test Facility
3m
Solar canopy system
10 m
Dual-function
prism light guide
Mirrored walls simulate a
large open-plan office
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UBC Portable Test Facility
Visualizing the Canopies on a
Multi-Storey Building
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Visualizing the Canopies on a
Multi-Storey Building
Solar Canopy Demonstration System
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Inside the Test Facility
Prototype of Dual-Function Light Guide
Multilayer Optical Film
T5 fluorescent
lamps
Optical Lighting Film
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Illuminance Measurement Conditions
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Electric Lighting only
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Daylight entering through the window only
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Daylight entering through the light guides only
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Daylight entering through window and light guides
Electric Lighting Only
Average Illuminance = 525 lx
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Daylight Entering Through
Window Only
Average Illuminance = 456 lx
Daylight Entering Through
Light Guide Only
1:00pm true local time
Average Illuminance = 742 lx
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Daylight Entering Through
Window and Light Guide
1:00pm true local time
Average Illuminance = 1200 lx
DALI Lighting System
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Control Software
Demonstration at the World Urban Forum
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Cost Benefit Analysis
• System cost:
– Because of hybridization, many features paid for by
other aspects of the building
– Dedicated solar lighting elements are the array of
heliostat mirrors, their control system, the
concentrating mirrors and the prism light guide film
• Cost effective purely in terms of energy savings
Cost Benefit Analysis
• Human factors argument are also powerful
– Glare reduction
– Contact with outdoors
– Color rendering
• We are not attempting to quantify these at this time,
although others are doing so
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Next Steps
• Detailed evaluation of system under different
lighting conditions
• Participate in user feedback/human factors studies
• Detailed cost benefit analysis
• Prepare for installation of demonstration system in a
real building
UBC Solar Illumination System
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