A support strategy for the promotion of photovoltaic uses for residential houses in Korea

► The unit cost of electricity from solar PV depends crucially on its capacity factor. ► We calculated the capacity factor of solar PV at various cities from the clearness index. ► We estimated the unit cost of electricity from solar PV using thermoeconomic analysis. ► We examined whether the capital subsidy program in Korea to solar PV is cost effective. ► This study determined that a measure based on the same payback period is better policy.