Life-cycle economic assessment for establishing the optimal government solar subsidy program in South Korea

Since the current government solar subsidy does not consider the economic effect that varies depending on the operating entity of the government solar subsidy program, the implementation of photovoltaic (PV) in multi-family housing complexes (MFHCs) has limitations. Thus, this study aimed to establish the optimal government solar subsidy program for promoting the installation of PV in MFHCs. Toward this end, this study established nine scenarios considering government solar subsidy programs and MAECH and conducted a life-cycle economic assessment. When installing the optimal power capacity of PV in MFHC, the range of the net present value in 25 years increase from US$8,873.54 to US$588,626.83 when the MAECH increased from 200 to 600kWh. When installing the maximum power capacity of the PV in MFHC, the shorter the target breakeven point is, the greater the government solar subsidy the government must support for the MFHC becomes. Government solar subsidies of up to US$966.46/kW and US$938.99/kW, respectively, are required to meet the economic profitability of the PV within 4 and 5 years of breakeven point. The results of this study make it possible for policymakers to establish a government solar subsidy scheme and for residents to determine the optimal government solar subsidy program.