a comparison of dc- versus ac-based minigrids for cost-effective electrification of rural developing communities

Sub-Saharan Africa continues to suffer energy poverty due to low grid expansion rates necessitated by low economic activities in those regions, sparse population distribution coupled with low household load demands, and insufficient power generation. On the other hand, small solar power microgeneration systems have emerged as potential alternatives to grid electrifications, enabling households to make modest investments into their power systems, and to modify those systems according to their changing economic and power demand circumstances. For rural social-economic development, electricity-beyond-lighting is needed. Without the grid, the only alternative is minigrids based on locally available renewable energy resources. In this work, we compare the merits and demerits of DC and AC coupled systems as pertains to costs, efficiencies, and overall performances. Research shows that power conversion stages are the biggest points of power losses in minigrids and therefore avoiding many conversion stages lead to improved overall system efficiencies. Research also shows that the best performances are realized when DC-inherent appliances are supplied with power from DC-coupled networks, supplied by distributed DC power generators such as PV. Simulation results show that when given choices, consumers choose to connect to DC networks with decentralized storage due to lowest operating costs, ease of expansion, and overall better performances when compared to other networks. Keywords: Minigrids, DC-coupled, AC-coupled, Conversion losses