Elia reported that these panels can produce up to 9 GW during peak conditions, depending on panel orientation and technical factors. “Any weather fluctuation, however small, therefore has a significant effect on the balance between supply and demand, which can lead to negative prices,” said an Elia representative. This typically happens during summer weekends or holidays when high solar generation coincides with low electricity consumption.
James Matthys-Donnadieu, director of markets at Elia, stressed the need for early action: “In 2024, we were careful in the summer, but this year, vigilance is required from spring onwards, due to the increase in installed photovoltaic capacity.” To ensure grid stability, balance responsible parties are responsible for aligning supply and demand, using summer forecasts provided by Elia.
If imbalances occur, Elia can utilize offshore wind farms or coordinate with foreign grid operators. In exceptional cases, large onshore solar or wind farms may be temporarily reduced, though residential systems are unaffected. Matthys-Donnadieu noted the broader implications: “The energy transition and the development of photovoltaic energy are good news for our energy independence and for the planet. However, they also present our system with several challenges in terms of grid capacity and stability.”
Elia calls for enhanced system flexibility to better manage periods of high renewable output and low demand. The operator encourages adjusting consumption to times when abundant, affordable renewable energy is available. “Adapting our consumption to times when a large amount of (cheap) energy is available benefits not only the system, but also consumers,” Elia stated. Dynamic contracts rewarding flexible consumption and new flexibility products are viewed as ways to optimize energy use.
For instance, consumers can charge electric vehicles at reduced costs during surplus renewable generation. Elia also pointed to Denmark’s “supply split” model, which allows devices like EV chargers to have separate electricity suppliers. To enable such advancements, Elia plans to work with distribution operators, suppliers, regulators, and industry groups to create a more efficient market framework, delivering benefits for both the grid and consumers.
