Seizing the electricity access gap with mini-grids: load estimation and optimal design

Seizing the energy access gap is a central objective in the international agenda, as it is a required precondition to enable sustainable growth, and is it positively interlinked with all other developmental goals. While rural electrification is steadily progressing in many developing areas, a change of pace is in order to achieve universal access in the next ten years. Alongside grid extension and standalone systems, mini-grids are considered a key technical solution to provide cost-effective, high-quality power to hundreds of thousands of people. Their diffusion is, however, hampered by many barriers and constraining factors, such as the lack of adequate governmental policies and unclear regulatory framework, limited access to financing due to unproven business models, and the high capital and operating costs due to lack of effective, standardized practices in the development and design phase. Academic knowledge production should contribute effectively to this complex scenario, by addressing the multiple governmental and industrial stakeholders, with the ultimate goal of establishing an enabling environment in which investments for rural electrification projects are attractive for private developers without relying on grants. The methodological and technical contributions proposed in this work have therefore the specific objective of helping increase the feasibility of mini-grids for rural electrification. The first challenge faced when setting up this research, was the one of data scarcity, that affects the rural electrification sector at multiple levels and makes difficult to develop academic contributions. Therefore, a first, cross-sectoral objective of the research work has been to overcome these limitations by streamlining data acquisition pathways through field missions in developing countries in East Africa (Kenya, Rwanda, Uganda) and Central America (Honduras, Costa Rica). This allowed to establish connections not only with rural communities but also with local universities, governmental entities and companies. These multiple-sided interactions between different entities coming both from developed countries and the global south have been part of the research method and entailed much more than one-sided data transfer. Therefore, they have been studied and conceptualized under the Triple Helix framework. As a first application of this approach, a critical analysis of existing business models for decentralized renewable energy solutions in sub-Saharan Africa has been carried out in partnership with non-profit and private actors, making use of actual operating data obtained from 21 mini-grids. Then, load profile estimation and modeling are tackled, as they are pivotal elements in the mini-grid development process, and are suffering from a lack of general understanding, data and tools to perform them. Two complementary approaches are presented, one based on effective field survey methodologies for the energy need assessment of rural communities and the other based on a clusterization and characterization of load profiles, built upon a unique, open-access database created for this purpose. Then, the optimal design of mini-grids integrating advanced, predictive operating strategies is addressed, with a contribution aimed at increasing their viability by reducing their computational requirements. This line of research, despite being conceived for and applied to case studies from developing countries, is relevant for hybrid mini-grids as a technological solution per se. Therefore, to demonstrate the extension of mini-grid application to isolated areas of developing countries, the case study of an hybridization and demand side management proposal for the mediterranean island of Ustica (Italy) is presented.