Swarm electrification for Raqaypampa: Impact of different battery control setpoints on energy sharing in interconnected solar homes systems

Abstract

In rural electrification, decentralized systems have proven to bring fast, affordable, and sustainable electricity supply for the last mile of energy access. Especially, solar home systems (SHS) have lately increased in number and impact. Recently, a new concept promises even better utilization of SHS and the potential for higher access to electricity. This concept is found under the name of swarm electrification, also known as interconnected SHS, nanogrids, or decentralized DC systems in rural areas. This paper studies the benefits of such interconnected SHS for a case study in the indigenous rural Highlands of Bolivia, an area called Raqaypampa. Our study emphasizes analyzing the energy sharing setpoints for the decentralized battery control and how the choice of these values influences energy distribution in the community. We draw concepts of energy justice into our discussion to evaluate different combinations of battery state of charge setpoints. Our study finds four types of households in Raqaypampa based on their demand for electricity. The modeled and simulated results of a potential energy sharing through interconnected SHS reveal three outcomes for the households based on the battery state of charge setpoints: Outcome I - Improving households, Outcome II - Depending households, and Outcome III - Deteriorating households. We conclude that a common approach of e.g. minimization of total unmet demand alone will not necessarily lead to just energy distribution, and it is crucial to integrate discussions about justice and community goals into the design process from the beginning.