Flexible solutions

As well as technical solutions, we are exploring other options to optimise utilisation of the electricity grid. For example, by making agreements with customers to reduce consumption capacity at peak times or to actively use capacity on the grid to keep the grid balanced. We refer to this as flexible (control) capacity and this is part of congestion management. The agreements we make with the customers are laid down in flex contracts. The flex contracts concluded in 2023 helped us to achieve our target of 45 MW of available control capacity. We realise this is not enough, however, and have therefore set an ambitious target of 500 MW for 2024.

A flex contract must be sufficiently attractive to participants and must ensure participants do not get poorer outcomes. At the same time, we have capped the amount we are prepared to pay in fees and we have opted for ‘cost-based fees’ for the use of flexible control capacity (see box). This means, for example, that Stedin pays a customer a fee for reducing the output capacity of a solar farm that is comparable to the revenue the customer would have realised on the ‘day-ahead market’ from the sale of the energy they would otherwise have generated.

Flexible control capacity in Middelharnis and Noordring

This year, congestion control capacity was frequently used in the Middelharnis and Noordring congestion areas. In both areas, this involved wind farms feeding in less energy at specific times at Stedin’s request. As a result, the grid load remained within the limits of what is acceptable for the grid and no outages occurred due to overloading.

We have an increasing number of solutions at our disposal to serve the market. In general terms, two types of solution can be distinguished: the ‘capacity limitation contract’ (capaciteitsbeperkend contract, CBC), which is used for the next 24 hours (day ahead), and ’redispatch’,through which we try to reduce demand for transmission capacity by purchasing additional capacity at particular times of the day (intraday).

Capacity limitation contracts

These contracts contain agreements on the flexible use of capacity for a period of several years. These contracts come in several forms:

  • Capacity control contracts – Large battery systems are an important tool in facilitating the energy transition. Battery systems help by feeding in or consuming energy at peak times. However, they can also cause more grid congestion. Capacity control contracts ensure that batteries do not operate in ways that cause such undesirable effects. In 2023, we signed the first six contracts with providers of large-scale battery systems, involving a total capacity of 18 MW. These include batteries at solar and wind farms, as well as stand-alone batteries.

  • Group capacity management – Businesses in congestion areas can help each other by exchanging energy without putting strain on our grid. For example, a company with a large solar roof can supply electricity to a refrigeration company with expansion plans. Although heavy-use customers in congestion areas cannot request additional capacity, plans can go ahead nonetheless thanks to cooperation and smart control. Stedin launched an initial pilot for businesses in Tholen (see ‘Energy hub’ box).

  • Static capacity limitation contracts – The electricity grid is not always fully utilised. By releasing capacity in certain time slots, Stedin is able to provide grid capacity to customers who can anticipate this. In 2023, Stedin applied this contract form on a limited scale in a number of pilot situations (see ‘Textbook example’ box).

Textbook example

Before the opening of Het Element, a new secondary school in Amersfoort, there was insufficient grid capacity to supply the school with energy. This jeopardised the opening. However, by looking for solutions with Stedin, the school was able to open its doors on the scheduled date. The school checked when it consumed the greatest amount of electricity, which was between 8:00 and 16:00 hours. The school has now agreed with Stedin that it will use less electricity between 16:00 and 20:00 hours, which is when households generally consume a large amount of electricity.

Redispatch

While capacity limitation contracts look a day ahead, redispatch contracts enable Stedin to make adjustments on the day itself. A redispatch contract is usually a temporary contract aimed at preventing grid overload in a congestion area. Stedin offers and manages these contracts via the Grid Operators Platform for Congestion (GOPACS). Stedin places the congestion situation as an order on GOPACS. Participants with a connection in the congestion area can respond by placing an order on an energy trading platform affiliated with GOPACS. The use of GOPACS is still in the development stage at Stedin. We expect that we will use GOPACS increasingly often.