Field performance of bifacal modules in South Africa

Abstract

This study presents the initial results of field performance analysis conducted on bi-facial modules installed on a fixed tilt rack and dual axis tracker system in Pretoria, South Africa. Bifacial modules produce better energy yield compared to monofacial modules depending on the geographical location, albedo of the back surface, height of a module from the surface and tilt angle. Currently multiple standards are under development to predict the bifacial gains and the field performance data is required to validate the models. This paper presents the bifacial gains over the monofacials without a high albedo back surface in a fixed tilt system, intercomparison of the grass cover, unpainted and white painted pavement and overall bifacial gain over the monofacials in dual axis tracker system. The bifaciality factor and efficiency curve of two bifacial types measured on indoor sun simulator is presented.