Estimating the technical and economic potential of rooftop solar photovoltaics on Bali

Abstract

The Indonesian aims to greatly increase the share of renewable energy sources in the electricity generation mix. Rooftop solar photovoltaics (RTSPV) are a potential generation method that can be used in support of this, with Bali chosen as a case study. No estimates of the total technical and economic potential of RTSPV on Bali exist in academic literature. Low spatial resolution statistical methodologies exist to estimate the technical potential of RTSPV, but these are not accurate on the sub-national scale of Bali. Methodologies with a medium spatial resolution are most suitable for an area of the scale of Bali, however existing methodologies cannot be used due to incomplete cadastral data. In this thesis a novel methodology is introduced that allows the use of incomplete cadastral data, in combination with land use data, to estimate the total rooftop area in a region at a medium spatial resolution. The total rooftop area is then used to estimate the total technical potential and the total economic potential. Using this method, the rooftop area of Bali is estimated to be 130 km2, and the technical potential 22.9 TWh/year. The economic potential for RTSPV is estimated to be zero, as RTSPV cannot compete with conventional generation methods at current capital costs (CAPEX) of RTSPV components of 1200 USD/kWp. It is estimated that at a CAPEX of less than 870 USD/kWp sufficient electricity can be generated annually to fulfill the estimated annual demand of Bali of 5.7 TWh. 96% of the entire technical potential can be achieved at or below the cost per kWh of conventional generation methods if the price of RTSPV installations decreases to below 650 USD/kWp. If the compensation paid by the Indonesian state electricity company PLN for RTSPV electricity that is supplied
to the grid is increased from 65% to 100% of the consumer electricity price, residential RTSPV installations can become economically viable at the current CAPEX of 1200 USD/kWp. This thesis will enrich existing literature on RTSPV potentials by introducing a novel methodology that can be applied in other regions with incomplete cadastral data. In addition, it provides a blueprint to estimate RTSPV potentials for other parts of Indonesia, and it supports policy makers by giving insight in factors that influence the economic potential of RTSPV on Bali and in Indonesia as a whole.