Sustainability of access to electricity through 17 functional off-grid solar photovoltaic systems after 20 years of operation in a remote wildlife sanctuary of India -a case study

• A first-time study results of 17 functional solar mini-grids in a wildlife sanctuary in India are presented. • The sustainability of Access to Energy for all through Mini-Grids in Remote locations is analyzed after 20 years of their operation. • Results show that mini-grids with controlled operation can meet the energy requirement of 100 % of the rural population. • Solar mini-grids can provide electricity access to deprived communities in developing countries. The decentralized solar mini-grids provide access to electricity in remote regions worldwide; however, the sustainability of these systems has always been a challenge due to technical, operational, and maintenance issues. The objective of this study is to address these concerns for the sustainability of mini-grids in providing electricity to the deprived population in the inaccessible regions worldwide. In this first-time study, a comprehensive analysis of 17 functional off-grid photovoltaic systems in a Wildlife sanctuary of India is presented. The results show that these systems are fulfilling the energy needs of 100 % of the electric loads of the rural population even after >20 years of installation. The battery utilization, which ranged from 26–76 % of the nominal capacity, changed to 31–57 % after capacity upgradation. The results show that the existing optimized mini-grid design with a compact power distribution network system is most appropriate for such remote locations, along with strategic planning, regular monitoring, and technology upgradation, demand optimization, and capacity enhancement. Regular operation and maintenance by locally trained personnel is another key factor for the sustainable operation of mini-grids in remote regions. The study identifies strategy and policy recommendations for solar mini-grids for developing countries worldwide.