In the summer of 2019, Swissgrid had to reduce export capacity to Germany (NTC) on the northern border of Switzerland to ensure reliable grid operation. A static NTC value of 4,000 MW had been agreed with neighbouring transmission system operators for export from Switzerland to Germany.
Load flow between Germany and Switzerland changed however in the past two years, situations increasingly occurring in the summer months where Germany relies heavily on importing, particularly from Switzerland. This resulted in the previously typical north-south flow in the direction of Italy reversing to a south-north flow in the direction of Germany.
A number of factors have simultaneously come into play in the summer months of the current year in both the grid and the market:
- A favourable hydrological situation led to a high level of Swiss hydropower production.
- Between June and August, the energy supplied to the load centres in northern Switzerland stemmed mainly from hydropower from south of the Alps or from imports from France due to the inspection times of Swiss nuclear power plants and seasonal decommissioning and construction work on the grid.
- This, in combination with increased export to Germany, resulted in significantly higher load flows on the Swiss 220 kV grid.
- Additionally, these flows from the 220 kV grid were reinforced by increased export opportunities from France to Germany (through flow-based market coupling in the CWE region) and any transits through Switzerland.
As a result, the Swiss grid recorded exports of up to 8,000 MW on several days during this summer. In addition, the Grid load was correspondingly high with increased violations of the (n-1) principle.
In consequence, Swissgrid limited the NTC values with neighbouring transmission system operators as part of regular operational processes to ensure secure grid operation.
Because of the NTC limits, no additional capacity was available during this time period in the corresponding daily auction (via the capacity auction platform JAO). In such cases, market participants can only utilise monthly and annual rights already purchased.
Swissgrid had to reduce the available capacities for monthly and daily auctions in the summer and autumn months of last year, and expects this trend to continue throughout the years ahead.
Swissgrid is cooperating with the transmission system operators of the neighbouring countries to optimise cross-border capacity so as to provide market participants maximum capacity for trading. The current static value of 4,000 MW will likely be replaced by seasonally adjusted, i.e. dynamic, NTC values.
It is not possible at this time to forecast how NTC values will be changed along Switzerland’s northern border due to a number of unresolved issues connected with the implementation of the Clean Energy Package, which entered into force in the European Union on 1 July.