Optimal dispatching of a photovoltaic-biogas hybrid system

Abstract

This paper presents an optimal dispatching strategy for a photovoltaic-biogas hybrid system for an off-grid institution. The aim is to prioritise use of the PV system to meet demand whenever available. If the demand is less than the PV output, the remaining power generated is dumped. If the demand is larger than the PV output, the imbalance is met by the biogas system. Since biogas production is continuous, the biogas system can supply power directly to the load and/or store energy during times when PV is meeting demand. During times when PV cannot meet the load the biogas storage system discharges to ensure that all generators run to meet the load. The results show opportunities for implementation of such autonomous systems in most developing countries where electrification rates are low. The outcome of this study is expected to inform micro-grid controller designers of the envisaged operation strategies. In cases where such a system is connected to the grid and feed-in tariffs and net metering are allowed, any excess electricity can be exported to the grid hence generating revenue or credits for the institution.