Investigation of a novel, building-integrated photovoltaic concentrator

• Main Author: Norton, Matthew Savvas Harry
• Published: University of Reading 2006
• Subjects: 621.31242
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555862

This thesis examines the performance of a building-integrated 10X photovoltaic concentrator proposed within the EU Framework-5 CONMAN project. The concentrator behaves as a window or skylight, allowing diffuse light to enter the building, whilst using mirrored slats to capture direct sunlight for conversion to electricity. The underlying logic is that by building integration, the proposed design can be economically and environmentally preferential to standard building-mounted PV panels in situations where the EU Energy Performance of Buildings Directive applies. A survey of building-integrated concentrator systems was conducted and indicated this to be a novel system. A technique of pressing to form the parabolic mirrors amenable to mass production was developed, in addition to a novel tracking system. Tests on BP LSBG cells indicated an approximate cell efficiency of 19% at the concentration levels expected. These design features in combination indicated that the cost of the system could be kept reasonably low, and a detailed design, called the 'Venetian Blind' was developed, constructed and tested. A biaxial model of the collector was developed, and a Visual Basic programme developed to simulate its output. Good correlation was found between the system model and the test data. When used to simulate annual output for the system in climates typical of the south of Spain, the model indicated that the system produced electricity at an approximate module cost of $8/equivalent Wp when not building integrated, and $5/equivalent Wp when building integrated. The system incurred longer energy payback periods than flat plate PV, but not substantially so when building integrated. Overall, 1 the optimised system is projected to produce electricity for 0.3$/kWh at good sites. Note that the system's potential contributions to-the passive solar gain of a building are likely to be very substantial, in addition to its electrical output.