Dielectric totally internally reflecting concentrator structure for vertical bifacial photovoltaic receivers

A new dielectric totally internally reflecting concentrator (DTIRC) design has been developed for use with bifacial photovoltaic cells. The structure incorporates the bifacial cell standing vertically at the base of the structure, immersed in dielectric. DTIRC structures with single-sided photovoltaic receivers, like CPC structures, are designed using the paths of the edge rays to calculate the sidewalls. If these rays successfully hit the receiver then all rays at lower angles will also hit the receiver. In a vertical DTIRC structure, it is not just the edge rays that need to be taken into account in designing the structure. Around the bifacial receiver, rays at normal and close to normal incidence are the hardest to totally internally reflect onto the receiver. Once outside the area closest to the receiver, a modification of the maximum concentration method is used to design the remainder of the sidewalls. Ray tracing has been performed to confirm that the vertical DTIRC structure concentrates light as expected. The structure gives a lower concentration than a CPC with vertical bifacial receiver, however it is also a shorter structure with more uniform flux distribution over the receiver (leading to lower losses in the photovoltaic receiver).