A review of hybrid renewable energy systems in mini-grids for off-grid electrification in developing countries

Rural communities in developing countries lack access to affordable, reliable, and sustainable forms of energy, which are essential factors for improving living conditions. These communities rely on diesel and kerosene, which are highly polluting compared to renewable energy technologies, to satisfy their energy needs. In this study, hybrid renewable energy systems (HRESs) have been analyzed, which are designed to overcome the fluctuating nature of renewables, for off-grid electrification. The results of this study—which covers many countries and examples—show that the successful integration of HRES is influenced by factors such as government support—and community organization — which is essential to keep these systems operating over the project lifetime. The levelized cost of energy (LCOE) of different mini-grids was compared and analyzed. The results reveal that by comparing the LCOE range of diesel (between USD 0.92/kWh and USD 1.30/kWh), solar photovoltaic (USD 0.40/kWh and USD 0.61/kWh), and hybrid solar photovoltaic/diesel (USD 0.54/kWh to USD 0.77/kWh), diesel is the most expensive technology. Additionally, the study addressed barriers that can hinder the implementation of mini-grids, such as lack of supportive policies and high capital cost. However, governments’ incentives are instrumental in lowering capital costs. These results are of particular importance for developing countries, where electricity supply via HRES is often quicker and cheaper than grid extension. The insights from this paper are a good starting point for in-depth research on optimal local design and ownership models, which can help accelerate the implementation, and lower the costs of sustainable electricity supply in remote areas.