Energy storage for reaching 100% CO 2 free and 100% RES — preliminary case study for Romania

The paper analyses energy production and consumption recorded for the Romanian power system in selected days and shows how storage resources can mitigate situations with 100% CO 2 free and 100% RES respectively, by simulating through scaling the production based on these new scenarios. The study assumes a similar power exchange with neighbors, to avoid drastic network reinforcement and to improve regional auto-consumption, thus improving resilience. Based on the studied days, the storage level, needed to maintain acceptable tie-lines cumulated power exchanges, is analyzed in terms of KPIs such as the total need of storage capacity in GWh, the power to energy ratio, and PV power to storage energy ratio. The results suggest similar requirements with the today trends in PV and storage pairing, thus inferring the feasibility of 100% CO 2 as well as 100% RES in the Romanian power system as being possible from the energy balancing point of view.