Limited-Size BESS for Mitigating the Impact of RES Volatility in Grid-Tied Microgrids in Developing Countries: Focus on Lacor Hospital

Electricity accessibility in Global South remains a challenge necessitating innovative solutions for reliable power supply. Grid-connected microgrids present a viable solution, especially for critical infrastructure requiring increased supply security. However, persistent issues such as renewable curtailment and grid instability necessitate advanced approaches. This paper, having the St. Mary's Hospital Lacor as a case study, demonstrates the effectiveness of a limited size battery in mitigating renewable curtailment and improving security of the supply in the transition to off-grid operations. Owing to collection of on-field data, a procedure was developed to reconstruct the potential RES generation from the curtailed profile. Subsequently, a rule based control strategy was developed to govern the power dispatch over a year in presence of a multi-parameter empirical model of the battery to optimally supply the load with the available generation portfolio of a diesel generator, PV and battery. Optimal sizing was conducted by means of a NPV analysis over a multiyear horizon calculating the operation savings and reliability improvements deriving from the initial capital investment in the storage system. Significant improvements in renewable production exploitation and off-grid resource adequacy are obtained with a limited size battery.