Wind turbines started participating in the Danish capacity market for manual reserves in a pilot between the country’s grid operator and an energy trading group.
The test carried out by Energinet and Energi Danmark marks the first time wind power was used to balance the country’s electricity grid, and showed that wind turbines can reliably deliver electricity when needed.
Danish wind farms already respond to grid needs through curtailment when there is a surplus of electricity on the grid.
But Energinet and Energi Danmark‘s ongoing pilot project – based on turbines in the east of the country – has shown that wind turbines can also be relied upon during shortages.
“Until now, we have been unsure whether it was safe enough to let wind turbines bid and deliver to the balance market — whether, for example, on Monday one could accurately predict how much a group of wind turbines would produce hour by hour on Tuesday,” explained Kia Marie Jerichau, head of the flexibility and systems services department at Energinet.
“But the project shows that the forecasts are so good that they can deliver what they have promised in advance, and that the plants have the necessary regulatory properties.”
Electricity traders such as Energi Denmark continuously buy and sell the electricity that is needed to balance the grid on a daily basis.
However, when deviations occur, operators like Energinet must be able to react to ensure a stable, secure supply of electricity.
In such cases, operators can buy so-called system services to balance the grid — for example, when consumption is higher than production.
Thomas Elgaard, division director at Energi Denmark, suggested this could help the energy transition, and act as a potential additional revenue stream for wind developers as they could make the capacity available in the balance market rather than selling electricity in the spot market.
“What we have seen in the pilot test has been extremely positive, and it is only the starting point that more wind power and other forms of renewable energy can help balance the grid and participate in different markets in the future.”