Abstract

A three-dimensional optical analysis of two dielectric, non-imaging concentrating covers for building integrated photovoltaics shows that an asymmetric concentrator is more suitable for use at building facades. For a wide range of solar incidence angles, optical efficiencies are over 90% for both concentrators. The optimum collection tilt angle for two different latitudes and the monthly and annual collected solar energy for both concentrators are predicted and compared to flat photovoltaic covers of the same photovoltaic and aperture area. Employing high transmittance materials for dielectric concentrating covers enables such refractive systems to achieve high solar energy acceptance thus requiring less photovoltaic material thereby reducing initial capital cost.