Economic Assessment of Rooftop Photovoltaic Investment by Considering Uncertainty Solar Irradiation: A case Study of Semarang City, Central Java, Indonesia

Rooftop Photovoltaic (PV) built by the private sector is an option to reduce the government’s burden in achieving the new and renewable energy target. However, the fluctuating global horizontal irradiation (GHI) value causes uncertainty in the profit of rooftop PV investment and causes the private sector to doubt. Therefore, this research analyses the impact of the GHI uncertainty on the economics of rooftop PV investments. This research used Semarang city as a case study. The uncertainty was modelled using the Monte Carlo simulation. The results show that the levelized cost of electricity (LCOE) is always below the tariff and above the generation cost. It implies that it is more profitable if it is built by the private sector (PLN’s customers) rather than build by PT. PLN itself. The LCOE of rooftop PV in Semarang has an average value of 8.23 cents USD/kWh with an average net present of 11,265 USD.