Performance analysis of a dielectric based 3D building integrated concentrating photovoltaic system

The use of concentrating photovoltaic systems (CPV) in building integration has spurred towards the development of newer products, which have the potential to offer the convenience of pleasing architecture and day lighting along with simultaneous production of clean energy. This paper addresses the energy transformations and the expected energy output of a low concentrating photovoltaic system designed to have a geometric concentration of 3.6×. The optical element used is a three dimensional Cross Compound Concentrator (3DCCPC) made from clear polyurethane material. Small sized silicon solar cells based on the Laser Grooved Buried Contact (LGBC) technology having an absorber area of 1 cm2 are utilised in the system. Both experimental and numerical analyses are performed confirming the optical, electrical and thermal performance of the system. While performing the optical analysis the concentrator was found to have a maximum optical efficiency of 73.4%. A maximum power ratio of 2.67 was observed when comparing the electrical output of the concentrator unit with a non-concentrating counterpart. The effects of non-uniformity caused by the use of the concentrator are analysed. The non-uniformity of flux distribution showed an average drop of 2.2% in the Isc values which is again reflected in the overall power output. Manufacturing defects like the cell and concentrator misalignments are addressed and their impact on the overall performance are verified by numerical simulations. The operating temperature of the solar cells was found to have a parasitic effect on the overall performance of the system. A maximum temperature of 332 K was observed in the solar cell at 0° incidence and a incoming radiation of 1000 W/m2 which brings down the overall power production by 14.6%. Finally, the expected system output over a given time period is presented showing the strengths and weakness while employing such a system