Households in Zeeland province that switched off solar panels for short times helped solve electrical grid congestion

Consumers can significantly reduce the load on the electrical grid at peak moments. This is a key finding from a pilot conducted by grid operator Stedin and energy supplier Eneco on the islands of Tholen, Sint-Philipsland and Schouwen-Duiveland last summer and autumn. Those customers saw the load on the electrical grid drop by as much as 57%. Participants were eager to do their bit. The pilot will be given a follow-up in the spring of 2025.

A small group of Eneco customers from the islands of Tholen, Sint-Philipsland and Schouwen-Duiveland in Zeeland province took part in a pilot to switch off their solar panels for periods on sunny days. At some moments, those three islands produce more solar electricity than they use. The participants were asked to manually switch off their solar panels a total of 10 times, following a safe procedure. Besides manually switching off their solar panels, the participants also found other ways to reduce the load on the grid: by using sustainable energy when it is available, including households without their own solar panels. Part of the group took their energy usage into account at switch-off times, for example by choosing those moments to charge their electric vehicle so that they did not feed any electricity into the grid even without switching off their solar panels. Self-consumption of solar electricity will be a key point in a larger follow-up pilot in 2025.

Motivation high
The most important reason for the participants to take part was the chance to help with the energy transition. By switching off a number of solar panels at peak moments or increasing self-consumption, it becomes possible to connect more solar panels to the same grid. Neither the days when the panels were switched off nor the amount paid in compensation had much effect on the results. Motivation was high, as were conversion and participation, despite the simple nature of the pilot. Whether compensation will work as a long-term solution and for larger groups of participants will be investigated further; that compensation is indirectly borne by everyone who draws electricity from the grid, in the tariffs they pay for the grid, which have climbed sharply in recent years.

Thoughts of a participant in the pilot
“I think it’s important to take part in initiatives to help the energy transition become successful,” explains Ad Nieuwenhuize, one of the participants. “Switching off my solar panels to reduce grid congestion in my area is one of the possibilities. For this pilot, I was asked to manually switch off my solar panels. In the future, I expect that to be automated, so that it takes less effort. Another big advantage for me as a customer is in the cost.”

Expanding the pilot
Stedin plans to expand the pilot in the spring of 2025. For that pilot, it will work with other energy suppliers besides Eneco, while also defining broader goals: 

• Using sustainable energy when it is available, e.g. choosing sunny moments to charge vehicles and run tumble dryers, including customers without solar panels.
• Encouraging customers to use more of the sustainable electricity that their own solar panels generate.
• Automating control to make the procedure simpler, within parameters defined by the customer. For sellers of solar panels and inverters for those solar panels, it is important to facilitate that control and regulate it according to fixed standards.

Smarter ways of thinking about energy can help to prevent power failures and voltage issues, Everyone can help, by making careful choices about when to use energy. The follow-up pilot will investigate what incentives and arrangements are required to encourage self-consumption and reduce peaks in the electrical grid.