Viability of performance improvement of degraded Photovoltaic plants through reconfiguration of PV modules

Abstract

This paper presents an analysis of the techno-economic viability of performance improvement of degraded PV plants through the reconfiguration of PV modules. To the best of the authors’ knowledge, this is the first time the analysis is presented in the literature after taking into account the effect of various degradation modes and the cost of I-V tracing of the modules. Various reconfiguration strategies are explored and they are benchmarked against each other by considering the gain in the performance and the cost of required module swaps to realize the respective strategies. A Python-based bottom-up model of a utility-scale PV plant is developed for this purpose by using a single diode model for each cell in each module. The economic feasibility of reconfiguration is analyzed for two representative countries − India and USA to contrast the effect of different labor costs. Eventually, guidelines for conditions under which reconfiguration could be a viable option to improve the generation of a degraded PV plant are presented. It is shown that reconfiguration may make economic sense when some / all of the following conditions are met: i) small sample of module-level I-V is measured ii) labor costs are low iii) degradation mechanism results in non-uniform / localized degradation iv) payback periods are short (< 2 years).