Optimisation of charging strategies and energy storage operation for a solar driven charging station

• Main Author: Gong, Jindan
• Format: Bachelor Thesis
• Language: English
• Published: KTH, Energiteknik 2019
• Subjects: Electric vehicle (EV); charging station; decentralized energy resources; linear programming; charging strategies; energy storage; energy system modelling; Elbilar; laddinfrastruktur; distribuerad elproduktion; linjärprogrammering; laddstrategier; energilager; förnybara energisystem; Energy Engineering; Energiteknik; Energy Systems; Energisystem; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-272006

The Swedish energy sector is undergoing transformational changes. Along with a rapid growth of renewables and a shift towards electromobility, the transformation is expected to bring challenges to the power system in terms of grid instability and capacity deficiency. Integrating distributed renewable electricity production into the electric vehicle (EV) charging infrastructure is a promising solution to overcome those challenges. The feasibility of implementing such a charging infrastructure system in northern Sweden is however uncertain, as the solar resources are scarce in the long winter period. This study aims to maximise the value of a solar powered EV charging station, placed in a workplace environment in Umeå. An integrated system model of the charging station is developed, comprising separate models of a solar PV system, a battery energy storage system (BESS), the workplace EV fleet and the building Växthuset, onto which the charging station will be installed. Three scenarios are developed to study the charging station’s system performance under different EV charging strategies and BESS dispatch strategies. Two additional scenarios are developed to study the potential grid services that the charging station can provide in the winter period. A techno-economic assessment is performed on each scenario’s simulation results, to measure their effect on the charging station’s value. It involves analysing the charging station’s profitability and how well the BESS is utilised by the end of a ten-year project period. The charging station’s grid impact is further assessed by its self-consumption of solar power, peak power demand and the grid energy exchange. The assessed charging station values indicate that the overall grid impact was reduced with dynamic EV charging strategies and that the BESS capacity utilisation was strongly influenced by its dispatch strategy. The charging station further implied a net capital loss under the explored scenarios, even while the dynamic charging strategies brought by a slightly ...