Flexible distribution design in microgrids for dynamic power demand in low-income communities

Abstract

Microgrids for electricity provision have an important role to play in achieving current international targets of electrifying poor rural communities around the world. In the East-African context, microgrid developers face challenges related to dispersed settlement patterns and high poverty levels that prevent many rural citizens from affording grid connection. Contextual factors influence demand for electricity, leading to uncertainties regarding development of consumption in newly electrified areas. Developers usually oversize the system in anticipation of growing demand, which leads to significant investment costs and economic risk in case projected growth fails to appear. Our focus in this paper is to introduce a concept of flexible distribution design — a process that can reduce initial investment cost and still be able to meet the long-term variations of the load, thereby reducing economic risks involved in microgrid development and thereby an entry barrier. We exemplify the usefulness of this design approach by seven steps of transfer capacity increase, which can be taken in sequence or in part, to achieve a distribution system configuration flexible enough to handle changes in electricity consumption, both increasing and in some cases also decreasing. Considerations on how flexible design would impact on system operation, power transfer capacity and demands on local technical expertise and maintenance are included. Importantly, the technical discussion is related to socio-economic aspects and the consequences for end-users as well as the utility. Real-world examples of application of the mature technologies from East-Africa address the feasibility and provide a context for the discussion.