Energy and environmental impacts of a 37.57 MW dc ground-mounted large-scale photovoltaic system in Malaysia: A life-cycle approach

Abstract

This paper estimated the environmental performance and primary energy consumption of a newly installed large-scale solar photovoltaic system of 37.57 MW dc in Bidor, Malaysia using the process-based life-cycle assessment approach. The mid-point and end-point impact categories were evaluated, and seven relevant indicators related to energy and global warming were determined. The global warming impact and energy payback time obtained were 30.95 g CO2-eq/kWh and 3.43 years, respectively. Furthermore, the global warming impact mitigation potential attained was 811 kilo metric tonne (ktonne) CO2-eq throughout the system lifetime. Analyses of contribution, sensitivity and uncertainty were performed to i) identify photovoltaic system components that substantially consumed primary energy and impacted the environment, ii) evaluate the effect of four key parameters, namely irradiation, performance ratio, system lifetime and electricity mix on the energy and global warming-related indicators, and iii) estimate the uncertainty range of the evaluated indicators. The results highlighted that the main contributor to the indicators is the photovoltaic module. Other significant contributors are the civil work and operational and maintenance but the contribution from these components is much lower than the photovoltaic module. Besides that, the cumulative energy demand, energy return on investment, global warming impact and global warming impact mitigation potential showed an improvement when extending system lifetime from 15 to 40 years, i.e. from 0.8136 to 0.3677 MJ, 4.61 to 11.25, 55.37 to 24.99 g CO2-eq/kWh and 407.36 to 1055.78 g CO2-eq respectively, except for energy payback time and global warming payback time, i.e. from 3.26 to 3.55 years and 1.42 to 1.71 years respectively.