Blueprint and implementation of rural stand-alone power grids with second-life lithium ion vehicle traction battery systems for resilient energy supply of tropical or remote regions
Developed societies with advanced economic performance are undoubtedly coupled with the availability of electrical energy. Whilst industrialized nations already started to decrease associated carbon emissions in many business sectors, e.g., by substituting combustion engines with battery-powered vehicles, less developed countries still lack broad coverage of reliable electricity supply, particularly in rural regions. Progressive electriﬁcation leads to a need for storage capacity and thus to increasing availability of advanced battery systems. To achieve a high degree of sustainability, re-used batteries from the electromobility sector are appropriate, as they do not consume further primary resources and still have suﬃcient residual capacity for stationary electrical storage applications. In this article, a blueprint for the electriﬁcation of a remote region by utilizing second-life lithium ion traction batteries for an integrated energy system in a stand-alone grid is presented and the implementation by the example case of a Tanzanian island in Lake Victoria is demonstrated. First, economic potentials and expected trends in the disposability of second-life lithium ion batteries and their foreseeable costs are outlined. Subsequently, key decision variables are identiﬁed to evaluate logistic aspects and the feasibility of the implementation of an oﬀ-grid electrical system in remote areas for economically and geographically unfavorable environments. The practical realization is pictured in detail with a focus on technical performance and safety speciﬁcities associated with second-life applications. Therefore, a new type of battery management system is introduced, which meets the special requirements of climate compatibility, low maintenance, enhanced cell balancing capability and cell conﬁguration ﬂexibility, and combined with a ﬁber-optical sensor system, provides reliable status monitoring of the battery. By carrying out on-site measurements, the overall system eﬃciency is evaluated along with a sustainability analysis. Finally, the socioeconomic and humanitarian impact for the people on the island is debated.