Introducing System Flexibility to a Multinational Transmission Expansion Planning Model

Grid investments are considered as sunk costs with a very long lifetime, particularly in an offshore grid context. The market mechanisms for cost recovery of these investments are exposed to an increasing share of variable power generation at the supply side, demanding more flexibility in the system. Hence, it is of great interest to account for these changes in tools being used for decision support. This paper presents an extension of an already existing mixed integer linear program (MILP) for transmission expansion planning (TEP), by including system flexibility in the form of energy storage and demand-side management. Moreover, an enhanced description of variable power generation is used to construct production profiles with a higher level of detail. The latter is achieved by simulating weather data for wind and solar incorporating higher temporal and spatial resolution than in previous studies. The impact of using new times series for variable power generation, and the introduction of system flexibility, are both presented separately using the North Sea area for a comparative case study with 2030 scenarios provided by ENTSO-E. The consequent results of interest include lifetime operational costs (OPEX), investment costs (CAPEX), and offshore wind power curtailment.