Rens Savenije is Commercial Director at Ventolines. The consultancy supports renewable energy projects from the earliest stages of development and financing through to construction and asset management. He too is seeing a sharp increase in the number of large-scale battery projects for commercial and industrial applications.
Significant pressure
Savenije:‘Onshore wind and solar are facing challenging conditions. Most of the large wind farms have now been built. Under the current support schemes, and due to uncertainty surrounding environmental regulations, new developments are progressing slowly. The same applies to solar parks, partly because of growing public opposition and increasing pressure on revenues caused by the rising number of hours with negative electricity prices. For large-scale batteries, however, the landscape has shifted considerably; many wind and solar parks are actively exploring the addition of battery storage.’
Below zero
Wind farms typically achieve a high number of full-load hours. According to Savenije, this creates a strong business case for batteries at wind farms. The battery can charge directly from the wind farm, thereby avoiding high grid transport charges. For solar parks, batteries offer an opportunity to ease pressure on the business case – by temporarily storing solar power when prices are low or negative, and feeding it back into the grid later when prices are more favourable.
Turning point
For Ventolines too, the lower threshold for battery projects is around 10 megawatts. This also includes large standalone storage systems, utility-scale batteries of 100 megawatts and above that actively participate in the imbalance, day-ahead and intraday markets, and increasingly also in local flexibility markets to help relieve grid congestion. Savenije agrees with the point made by Bosschaart: the revenue model for these batteries remains challenging due to high grid tariffs. However, he also points to a recent turning point that is now accelerating developments.
Financial close
In 2024, Dutch transmission system operator TenneT introduced a new contract structure: the time-dependent transmission right (TDTR). Connected parties receive a 50 per cent discount on transmission charges. In return, they may face restrictions on grid usage for up to 15 per cent of the time during peak periods. TenneT has 9.1 gigawatts of TDTR capacity available, of which approximately 6 gigawatts is expected to be allocated to battery projects. Savenije: ‘As a result, standalone projects can now be financially viable and reach financial close. The outlook for these storage systems is therefore positive as well. In the coming years, several major standalone projects are expected to be realised. The first of these are currently under construction and are scheduled for completion in 2026 and 2027. The key question is what will happen after 2030.’
Levelling
According to Savenije, significantly more wind and solar capacity will still be needed to achieve the energy transition. The same applies to batteries, which are essential for balancing electricity supply and demand, reducing volatility and price fluctuations, safeguarding security of supply and easing grid congestion. ‘As things currently stand, the rollout of standalone batteries is likely to slow towards the end of this decade once the projects with TDTR have been realised and grid tariffs continue to rise. Developers without access to TDTR capacity are already looking beyond the Dutch border, where market conditions are more favourable. It is important to establish long-term policy now; companies need certainty, and projects like these are not delivered overnight.’
This article was published in Storage Magazine – December 2025 edition (Dutch).
