Technical Modelling and Market Feasibility of V2X Services for Enhanced Grid Stability and Efficiency in Renewable-Rich Distribution Networks

Abstract

This thesis evaluates the techno-economic role of electric vehicle (EV) battery participation in a renewable-integrated distribution-network context using the Vaasa/Sundom area in Finland as the case study. The study focuses on how EV-based flexibility can support a local wind– photovoltaic (PV) storage system by improving renewable-energy utilization, reducing dependence on the external grid, lowering curtailment and influencing the levelized cost of energy (LCOE). The techno-economic analysis was carried out using the Hybrid Optimization and Performance Platform (HOPP) in a Python code workflow. The model was based on electricity demands from three substations J06 Sulva, J07 Sundom and J09 Vaskiluoto, wind-resource data, PV capacity factors, electricity spot prices, stationary battery assumptions, EV battery assumptions and technology cost parameters. The annual simulation was performed over 8760 hourly time steps. Three cases of EV participation were considered: NoEV, BEV50 and BEV80. For these cases there are four different TargetUnmet presenting the maximum share of annual demand that the external grid can supply with the remaining demand supplied by local wind generation, PV generation, stationary battery storage and EV battery if applicable. The lowest configuration was Target80Unmet_NoEV with an LCOE of 89.32 €/MWh, clearly showing that the zero-EV case was the most viable one when the local renewable supply was the lowest. But things changed when a higher percentage of the demand had to be met from local sources. In the Target40Unmet and Target20Unmet cases use of BEV50 and BEV80 led to lower LCOE compared to NoEV demonstrating that EV flexibility is more important with more stringent localsupply requirements. It was also observed that there is a strong trade-off between grid dependence, renewables overbuilding, storage need, curtailment and the system cost. Several scenarios achieved curtailment reduction with stationary battery and even in a few cases battery storage did not entirely replace stationary storage. The price-based dispatch analysis also showed that the EV batteries can provide added value, by being charged at low prices and discharged at high prices. In conclusion, all results indicate that V2G should not be treated as a standalone solution, but rather as a flexibility resource to be used in combination with a larger wind–PV–storage system.