Development of characteristic equations for PVT-CPC active solar distillation system

This paper deals with the development of analytical characteristic equation for N identical fully covered photovoltaic thermal (PVT) compound parabolic concentrator collector (CPC) integrated solar distillation system which is similar to Hottel-Whillier-Bliss equation of flat plate collector (FPC). The partially covered PVT has disadvantages like (a) thermal performance is lower due to higher top loss coefficient, (b) maintenance is higher and (c) fabrication is expensive. These problems are fully addressed in the case of fully covered PVT for the same watt peak. The development of analytical characteristic equation for the proposed system consists of writing energy balance equations for its various components. The results of proposed N-PVT-CPC integrated active solar distillation system [case (i)] has been compared with fully covered N identical PVT-FPC integrated solar distillation system [case (ii)] and conventional N identical FPC active solar distillation system [case (iii)]. It has been observed that average instantaneous efficiency of case (i) is higher than case (ii) by 10.60%, but lower than case (iii) by 20.74%.