High Withdrawal from Dutch Gas Storage
The winter of 2024/2025 was characterized by higher gas withdrawals from storage than can be explained by temperature alone. The security of gas supply was not compromised. With gas storages for 21% full at the end of the winter, timely filling of seasonal storage for the winter of 2025/26 is a concern.
Between mid-October 2024 and early February 2025, more than 30 TWh was produced from Dutch gas storage in addition to the volume that is expected based on temperature. This is due to commercial considerations made by market parties in supplying the market. This extra withdrawal means that about a quarter of the stored volume was produced as a replacement for other supply.
The winter of 2024/2025 ranks among the three warmest winters in the past 30 years. Some colder periods this winter led to temporarily higher gas demand, but over the entire winter period, this additional gas volume was small. Periods with less wind and sun ('dunkelflaute') also led to increased use of gas-fired power plants to balance the electricity system. Here too, providing flexibility was essential, but the extra gas volume was too small to explain the higher use of gas storage.
As stated in the 'Analysis on security of gas supply’ published in September 2024, "the GTS analysis shows a minimum required volume in seasonal storage of 110 TWh at the beginning of the winter season 2025/26". This volume is based on criteria that are established in the Dutch Gas Act. It describes developments in the gas market and assumes a cold year, with extremely low winter temperatures.
These assumptions have not changed since the most recent analysis in September. The filling of 110 TWh by November 1, 2025, therefore, remains unchanged.
The technical capacity to fill seasonal storage does not pose a barrier to achieving the fill rate by November 1. However, a point of concern is that the difference between the price for summer gas and winter gas currently makes it commercially unattractive for market parties to replenish seasonal storage with the required 80 TWh.
The minimum fill rate for seasonal storage aims to guarantee supply security, even in an extremely cold year. It does not take into account a prolonged supply outage. Preparing for such an event requires additional gas storage, which may also be needed in the summer. Separate rules must be established for such emergency stock, in a Northwest European context. For this, see also our response, section C, to the draft ‘wetsvoorstel bestrijden energieleveringscrisis’ (WBE).