Evaluation of Hybrid Solar Lighting for Residential Application in Kamloops, BC

Abstract Outline

Hybrid Solar Lighting, a daylighting system which utilizes mainly sunlight to illuminate interior spaces, has been conceptually existent for more than 30 years. As the quest to reduce energy consumption in a sustainable, responsible way advances, so too has the conceptually viable principle of solar daylighting. The latest research in sunlight collection and distribution within buildings has resulted in commercially available, out-of-the-box systems for installation on a residence. The question that this paper addresses is: What is the cost and payback information on the latest commercially available hybrid solar lighting systems when applied to a home with a full basement in Kamloops, B.C., and are there ways to moderate these expenses, ie. build your own?

Firstly, an analysis of the lighting needs in an original home design that includes a full basement will quantify the light output requirements of the desired system. IESNA standard lighting calculations will determine the lumens output and light distribution characteristics desired. Illustrations and calculations will reveal that the lighting needs of a residence require a modest system of supplementary solar lighting as compared with applications that have been primarily aimed at commercial lighting needs. Directional orientation data for local solar light collection will be gathered from area's solar product suppliers and installers to determine the optimal parameters for solar tracking devices.

Tabulated costing information, including shipping and installation estimates, will enable a comparative analysis of the commercially available hybrid solar lighting systems. The variety of collection systems, and associated costs to manufacture, will be a primary factor in choosing the most cost-effective design. Exotic systems containing extraordinary optic assemblies of individual lenses that track the sun have high costs associated with their manufacture, control devices and shipment. Parabolic dish collectors have inherent cost efficiencies in that dishes and tracking systems have already been pioneered and cost deflated in the satellite television industry, so commercially available versions of this system type will be expected to fare well. Large core optical fibre, the light conduit from rooftop to interior, is an inherent and supplied component to all of these systems, and its performance will be compared with the more common communications-grade fibre optic cable that may be obtained at a lesser expense.

Finally, the initial cost comparisons will reveal that one manufacturer has the lowest priced system to supply the light output required, and the summarized costing information will be assessed against the time to payback its purchase. Comparison with conventional light sources including incandescent and fluorescent lighting at average electricity supply rates will reveal that the payback time will be lengthy.

The author shall examine cost-reduction strategies, and, as addendum, report on the attempted simulation of a home-built hybrid solar lighting solution. Ideas for this simulation include sourcing a minimum 48" diameter used satellite dish and tracking system, having the surface reflectorized, and mounting a secondary element to strip the infrared and ultraviolet components from the sunlight. Utilizing surplus commercial communications-grade fibre optics and lenses to disperse the light will further reduce costs, and will lead to the finalization of the home-built HSL experiment. The success of the experimental component of the research will be a footnote to answering the paper's question: What is the cost and payback time for installing a commercially available hybrid solar lighting system in a residential application in Kamloops, B.C.?