All participants in the integrated European electricity market have agreed on common definitions of the transmission capacity for international electricity exchanges, including the Net Transfer Capacity (NTC). The NTC is an important basis to anticipate and plan cross-border transactions. Thus, the establishment of NTCs is one of the essential tasks of the transmission system operators (TSOs) to enable market participants to carry out energy trading without jeopardising grid stability. TSCNET shareholder Swissgrid, the Swiss TSO, along with the neighbouring TSOs, determines the NTC values on all four Swiss borders on an annual, monthly and daily basis.
In the summer of 2019, Swissgrid had to reduce the NTC on the national northern border to Germany to ensure reliable grid operation. Originally, a static NTC value of 4,000 MW for exports from Switzerland to Germany had been defined with the neighbouring German TSOs. However, the load flows between the two countries have changed in the last two years. Situations in which Germany is dependent on imports, especially from Switzerland, occurred increasingly in the summer months. As a result, the previously typical north-south flow towards Italy reversed to a south-north flow towards Germany.
Other simultaneous factors also affected the Swiss grid load, such as the high level of Swiss hydropower production, the inspection times of the Swiss nuclear power plants and the seasonal decommissioning and construction work on the grid. In combination with the growth in exports to Germany, this led to significantly higher load flows in the Swiss 220kV grid, which were additionally reinforced by increased export opportunities from France to Germany through Flow-Based Market Coupling (FMBC) in the Central Western Europe (CWE) region and transit through Switzerland.
In fact, exports of up to 8,000MW were recorded on several days this summer. For this reason, Swissgrid, together with its neighbouring TSOs, has limited the NTC values for a secure grid operation. Swissgrid continues to cooperate closely with these TSOs to optimise cross-border capacity. The current static value of 4,000MW is expected to be substituted by seasonally adjusted dynamic NTC values. However, due to the implementation of the “Clean Energy for All Europeans Package” (CEP) of the European Commission, it is not yet possible to predict exactly how the NTC values at Switzerland’s northern border will develop.