Considerations of the Limitations of RES hosting capacity at the Transmission System Level

In this paper, a methodology for calculating the hosting capacity of renewable energy sources (RES) in power systems, while focusing on the limitations arising from the Transmission System operation, is developed. For the developed approach, the power system of Crete, after the completion of the first phase of its interconnection with the Hellenic Interconnected Transmission System (HITS), is examined. The RES technologies considered are those of onshore wind farms (WF) and photovoltaic (PV) plants. At first, hosting capacity is investigated based on the limitations of the HV/MV substations, solving an optimization problem. Subsequently, the substation-level results are used to simulate the power system of Crete, solving the problem of the optimal power flow for each hour of the year. In this way, the effects of high integration of RES in the transmission system are observed, as well as the violation of the limits of the interconnection lines, to estimate the final hosting capacity of the island.