Determining the techno-economic benefits of energy storage in solar PV mini-grids: Study in rural regions of sub-Saharan Africa and India

Abstract

The aim of the study is to determine the technical benefit provided by the battery in a solar mini-grid. Mini-grids are used to increase electricity access to regions which lack access to the main grid. Existing literature on mini-grids in rural areas displayed the potential of electricity access. However, the lack of research in the battery utility in solar mini-grids in existing literature resulted in the aim of the thesis. The study was conducted with a focus on the technical and economic aspects. The first step was to compare the effect the types of load profile has on the capacity on the battery. The next step was to compare the effect of battery in an economic perspective. An indicator called economic utility was found, which equates to the extra time required to get the investments back if the battery is installed in the system. This was calculated by comparing the investment costs and revenue from tariff, for a system with and without a battery. A simulation model was used to represent the system. Three scenarios were created as an input to the simulation model. These scenarios represent different characteristics of load profiles, which captures the data from previous research in different regions. The scenarios also account for the change in solar insolation in different geographical regions and at different times of the year. Results were extracted from the simulation model and economic utility was calculated. The results conclude that the solar insolation does not have a large impact on the battery capacity. However, the load profile has a profound impact on the battery requirement. Both the peak load demand and the total daily load was proportional to the battery requirement. The investment costs were found to not be directly dependant on the battery capacity but the economic utility was found to be proportional to the investment cost of the system.