A socio-technical approach to increasing the battery lifetime of off-grid photovoltaic systems applied to a case study in Rwanda

Off-grid solar photovoltaics (PV) are promoted as an economical renewable energy system for providing electricity in remote locations far from the grid. However, without on-going maintenance, the performance of these systems will diminish due to battery deterioration leaving them unable to provide the service they were initially designed for. This paper presents analysis and results from a four week cross-disciplinary investigative study carried out in September 2012 into the performance of off-grid PV in health centres and schools in rural communities in Rwanda. A socio-technical approach was taken to understand the reasons for failure. A strategy was subsequently developed to influence user behaviour and increase the PV array size to reduce capacity shortage through the year and improve the lifetime of the lead acid batteries found on these systems. According to the results obtained, the total costs to implement off-grid PV systems can be reduced. Furthermore, the proposed strategy reduces the operating costs of PV below that of a diesel generator according to a projection of prices found in Rwanda which is important in a donor led installation model.