Applying soft-link and geospatial methods for optimal hybrid microgrids and electric network designs: A case study on rural Mozambique settings

Abstract

Decentralised-based hybrid renewable energy systems represent one of the cost-effective solutions for supporting access to and the provision of reliable and secure electricity services in rural developing regions. Electrification planning tools considering the specificities of targeted areas concerning uncertainties about energy demands and resources, including the technology-cost trends, are essential for proper system integration. This work, therefore, proposes a comprehensive geospatial-based optimisation modelling framework based on GISEle tool, which was expanded to size hydropower technology in addition to its integrated wind and solar capabilities. Moreover, its procedures were interlinked with two external open-source assessment tools: the SWAT model for hydro resource potential and RAMP for energy demand, combined with tailored publicly available geospatial and interview-based data. The newly expanded framework was applied to the Majaua-AP case study in Mozambique by modelling three evolving demand scenarios under two community-grid spatial scales to plan a cost-effective electrification strategy. The analysis results emphasise that communities with differing population sizes, and power pick values can be identified in any region depending on the project settings. Additionally, it revealed that local circumstances influence the best techno-economic sizing regarding optimal network distribution and hybrid microgrid configuration designs. The grid routing layout shows a good approximation compared to ground realities. For each community, a portfolio of generation system configurations including either diesel+renewables (PV/Hydro/diesel/batteries, PV/diesel/batteries) or 100 % renewables share (PV/hydro/batteries, PV/batteries, and hydro/batteries) were achieved. The latter becomes mostly attractive under fixed demand and high fuel price scenarios; among individual community-based system configurations, the net present costs (NPC) range from US$k41–5384 (grid expansion) and US$k152–22,562 (generation) while US$k19,156 (grid expansion) and US$k46,426 (generation) considering the whole region. The levelised costs of electricity (LCOE) ranged from US$/kW 0.112–0.247. Finally, the evolving demand including hydro in the technology mix allowed substantial LCOE reduction in most of the installed communities.