Luminescent and geometric concentrators for building integrated photovoltaics

In developed countries 60% of the electricity consumed is attributable to commercial and public buildings. Even in the UK, the solar energy incident on buildings is more than 7× the electrical energy they consume. This represents a problem (the management of solar heat gain and glare) but also an opportunity that may be taken advantage of using complementary concentrator technologies. We are investigating conventional geometric and luminescent concentrators that may be combined to optimally harvest the direct and diffuse components of sunlight within a double glazed window unit. Initial results suggest that the combined system can achieve power conversion efficiencies approaching 20% under standard AM1.5g illumination at normal incidence.