Flexibility index and decreasing the costs in energy systems with high share of renewable energy

Highlights: • Soft-linking method for EnergyPLAN and a Python code presented. • Large number of scenarios with different technology options simulated. • Energy system's flexibility enhancements analysed and presented for 0–100%RES. • Flexibility vector ease following of various national energy system configurations. • Comparison of different energy transition pathways of national energy systems. Recent European Green Deal includes decision to become carbon neutral and even carbon negative region in order to tackle the climate crisis. Main technical challenge and a key factor in techno-economic analysis of the energy system of the future, based on variable renewable energy sources, is their variable production and its integration. In order to deal with this problem in long-term energy planning, different approaches have been tried, focusing on overcapacity, storage capacities and sectors coupling with heating and transport. In this research, different flexibility options, storage and demand response technologies are modelled on a national energy systems level. With the case study area modelled in EnergyPLAN model, the goal of the research is to show how each flexibility option influences the economically feasible generation capacities of renewable energy sources, storage technologies and demand response in order to reach a certain share of renewable energy in final energy consumed. To follow the numerous possible configurations of the system, flexibility index for each option and a flexibility vector for each scenario are introduced. Results show which flexibility options play key role in important steps of energy transition to 70%, 80%, 90% and 100% RES energy system.