Earlier this year, Tennet’s large-scale introduction of time-dependent transmission right (TDTR) contracts in the Netherlands offered a glimmer of hope to more than 70 GW of customers, mainly large-scale battery energy storage projects, currently stuck in the grid connection queue. According to the latest information, the lion’s share of the newly-unlocked grid capacity will be allocated to batttery storage.

The analysis by the Dutch TSO reveals that up to 9.1 GW of capacity is available on the high-voltage grid during off-peak hours – capacity that could be effectively utilized through TDTRs.

TDTR give customers connected to the TenneT high-voltage grid the right to transport for a fixed number of hours per year, at least 85% of the time. This applies to both electricity purchase and supply. During the remaining 15% of the time, TenneT can (partially) limit the purchase or feed-in of electricity, for example in the case of expected peak periods. Under the deal, TenneT should inform the customer of these restrictions at least one day in advance.

As such, TDTR is particularly interesting for companies that can use their energy flexibly, such as battery energy storage systems, the processing industry and companies with their own emergency facilities. According to TenneT’s calculations, flexible grid users can save up to 65% on grid tariffs through a combination of TDTR and intelligent use of time-dependent tariffs.

Speaking at the Energy Storage Global Conference in Brussels last week, Bob Ran, business developer flexibility, strategy and partnerships at TenneT, revealed that around two-thirds of TDTR capacity will go to battery storage, supporting roughly 6 GW of projects. However, more than half of the battery applications may not receive the full requested capacity, potentially forcing developers to downsize their projects.

Many developers are still waiting for an answer from Tennet as to weather or not they have received TDTR. According to Ran, this should become clear before the end of the year.

Ran also noted that TenneT’s connection queue in the Netherlands currently includes around 60 GW of battery storage, while the nation’s current peak load is about 20 GW. Ran also provided an update on the connection queue as of September 1, 2025, noting that 4.1 GW of projects are in the realization phase – meaning the project developers have ordered the grid connection to TenneT to be built – a process involving costs of millions of euros. Meanwhile, 29 GW of battery storage projects remain in the basic design stage.

Tennet estmates that between 5-7 GW of battery storage will be economically feasible in 2030. It also calculates in its 2050 scenarios that there will be between 14-27 GW of transmission system-connected batteries in the Netherlands.

Despite the promise of TDTRs, the Dutch battery energy storage sector faces significant challenges, including the absence of a national storage target, no capacity mechanism, and a lack of subsidies. Developers must also contend with a highly congested grid, high grid tariffs, and no exemptions for BESS, making large-scale deployment costly and complex. Nevertheless, approximately 1 GW of battery storage projects are already operational, demonstrating the sector’s gradual but steady growth.