Evaluation of the Flexibility of Off-Grid Facility Planning Against the Uncertainty of Electric Demand Growth

Abstract

Off-grid systems are an effective approach to power supply for areas that are distant from urban areas and away from major power sources. Many countries and regions have adopted off-grid systems for off-grid areas. On the other hand, there are not many studies that consider off-grid systems for existing grids in order to improve costs. For regions where the scale of electricity demand is becoming smaller in relation to the scale of transmission facilities, and cost-effectiveness is deteriorating, going off-grid is expected to have a significant impact on reducing the overall cost of the electricity system. The facilities to be introduced for off-grid operation are expected to be small renewable energy power sources and storage batteries, which can be added or removed in a short period of time, and thus the facility configuration is expected to be more flexible than the conventional transmission facilities. In this paper, a decision tree analysis method is used to evaluate the cost of the off-grid system considering the uncertainty of electricity demand, and a comparison with the conventional system is made. By giving multiple options for capital investment against the uncertainty of long-term fluctuations in electricity demand, the optimal type and capacity of facilities can be selected at each investment timing. The estimation results show that OG is more effective in dealing with fluctuations in electricity demand, especially in situations where electricity demand is expected to decrease.