Low gas storage bookings for gas year 2025-26 may already be driving withdrawals and may continue to do so in the coming months.
German stocks were at about 79.8TWh on Tuesday morning, filling 31.8pc of capacity. That was well below the 131TWh three-year average for this date and the 171TWh in storage a year earlier.
Stronger withdrawals this winter were at least partly driven by higher heating demand as well as slower European imports of LNG and Russian pipeline gas compared with a year earlier. But market dynamics for upcoming storage years may also be encouraging withdrawals. A backwardated forward curve, with prompt prices holding substantially higher than contracts in winter 2025-26 and further along the curve, has incentivised the stockdraw over maintaining stocks. That said, prices for the summer quarters have risen above the prompt recently, so some firms could have a slight incentive to keep gas in storage past the end of this storage year.
But the inverted THE summer-winter spread has disincentivised capacity bookings for the upcoming storage year. Summer prices holding above winter prices removes the commercial incentive to inject or book storage space profitably. And storage operators have struggled to sell space in recent months, with many auctions closing unsuccessfully as bidders cannot profitably hedge injections for the contract period.
In the prevailing environment, only about 55pc of all German storage space has been booked for the 2025-26 storage year, leaving at least 103.5TWh of capacity unallocated, data show (see data and download). By contrast, firms had booked 99.7pc of German capacity for the 2024-25 storage year.
Storage sites with low or no bookings might be driving withdrawals, as firms near the end of some storage contracts. At sites where some capacity is booked for the next storage year, firms could sell their stocks to other capacity holders if there is no financial incentive for withdrawing it. But at the six sites with no 2025-26 bookings yet — Rehden, Wolfersberg, Harsefeld, Frankenthal, the VNG-operated Jemgum caverns and SEFE's Speicherzone Nord — firms cannot sell gas in-store as there are no available buyers to transfer gas-in-store to, incentivising firms to empty stocks ahead of the summer 2025 filling season.
Consequently, sites with no booked capacity for the upcoming storage year currently are filled less than most other German sites (see graph). The remaining sites suggests a correlation between 2025-26 bookings and stocks, as sites with a lower proportion of capacity booked for the next storage year tend to be less full, following stronger withdrawals this winter (see withdrawals trajectory graph).
Stock dilemma
Before the 2024-25 storage year ends on 31 March, any capacity holder left with stocks must decide either to withdraw that gas or sell it to a company holding 2025-26 capacity, if there is sufficient storage space booked at the individual site.
Barring additional capacity sales, that suggests that about 7TWh may need to be withdrawn on contractual grounds alone, not accounting for weather or withdrawals from fully-booked sites. About 5.6TWh of that is stored at Rehden, Germany's largest storage site, whose operator SEFE Storage allows capacity holders to withdraw 10pc of their stocks up to two months after the storage year ends. Rehden was filled to 12.1pc of capacity on Tuesday morning, leaving about 1TWh to be withdrawn even if all capacity holders utilise that 10pc allowance.
Four of the six sites with no 2025-26 bookings are depleted fields or aquifers, which have lower withdrawal and injection rates than salt caverns and offer capacity holders less flexibility to react to unusual price spreads. Caverns often offer faster injection and withdrawal speeds, so could still be used economically in summer by, for example, reacting to price volatility rather than seasonal spreads. Faster cycling also allows cavern capacity holders to wait longer before starting pre-winter injections, potentially allowing them to wait until the summer-winter spread normalises before injecting. Slower-cycling sites such as aquifers and depleted fields are usually drawn down more consistently in winter as their slower injections and withdrawals reduce their flexibility.
That said, some operators might need to inject into caverns to maintain their structural integrity. This might stop withdrawals or possibly support a minimum of injections ahead of or early in the filling season. German storage operator Uniper Energy Storage bought some gas to store as de-facto cushion gas at its Etzel EGL and Etzel ESE sites last week to comply with German law. Restrictions on minimum pressure are enforced by mining authorities and can differ by site, storage operators have told Argus.
