kia marie jerichau og thomas elgaard foto robert wengler
Kia Marie Jerichau, Energinet, and Thomas Elgaard, Energi Danmark. Photo: Robert Wengler

Milestone: Wind turbines can balance the electricity grid

For the first time ever, wind turbines have taken part in the capacity market for manual reserves, thus helping to supply the services that Energinet needs to maintain balance in the electricity grid. A new pilot project proves that wind turbines – despite wind and weather – are reliable and can supply exactly when needed. Energi Danmark, a leading Danish energy trading group, and Energinet, who are behind the project, have thus taken a major step towards greener balancing of the Danish electricity grid.

Can you rely on wind turbines if Energinet suddenly needs to increase power generation to maintain balance in the Danes' electricity grid?

Yes, you can. 

This is the result of a pilot project which the balance responsible party and energy trading group Energi Danmark and the national transmission company Energinet, who is responsible for the security of supply in Denmark, have recently carried out. 

Even though wind turbines generate power as the weather permits, it is possible to predict generation so precisely today that wind turbines can supply the balancing reserves that Energinet regularly needs. This means that wind turbines can be included on equal terms with power stations which, until now, have been the only suppliers readily able to turn up or down generation if a fault occurs in the electricity grid, a wind front is a little less windy than originally forecast, or consumption is greater than expected.

"Up until now, we have been uncertain as to whether it was safe to have wind turbines make bids in and supply reserves in the balancing market – whether, for example, on Monday, it was possible to predict exactly how much a group of wind turbines would generate hour by hour on Tuesday. However, the project shows that forecasts are so good that wind turbines can deliver as promised and that the units have the necessary regulating capabilities. This is a major milestone for the green transition – it is quite simply a necessity that renewable energy sources can also supply balancing services when the entire electricity system is green, says Kia Marie Jerichau, head of the Flexibility and Ancillary Service Department at Energinet, and she goes on to point out that Energinet is continuously working to bring new technologies into the balancing services markets.

Normally, electricity traders continuously buy and sell the electricity needed on behalf of consumers and electricity producers – and thereby they also maintain the overall balance in the electricity grid. But when deviations occur, Energinet must be able to respond to maintain stable and safe operation and the security of electricity supply. Therefore, Energinet procures so-called ancillary services to balance the grid, for example when demand exceeds generation. 

The green transition increases the need for balancing services 
As wind and solar energy make up increasingly more of electricity generation, demand increases because we need electricity for electric vehicles, electric heat pumps, etc., and still more of the conventional power stations are decommissioned, Energinet faces a greater need for ancillary services from new types of technology. This is the reason why the pilot project was launched, and the first stage only involves the 'slow' manual reserves, mFRR, in the capacity market. 

Wind turbine power is already used as the primary resource for 'special regulation', where wind turbines are switched off when there is a surplus of electricity in the electricity grid and a need for downward regulation. However, this pilot project has shown that wind turbines can also be ready on the sidelines and supply upward regulation.

Energi Danmark: Pilot project only the first to come
Energi Danmark hopped on board when Energinet announced the tender for the pilot project in December 2019.  Today, Energi Danmark acts as balance-responsible party for many wind turbine owners and, among other things, helps the owners to optimise energy generation, and it is therefore only natural that they joined this project.

Thomas Elgaard, Division Director at Energi Danmark and responsible for optimisation, balancing and production, sees great promise in the project. Both for the green transition, but also for the earnings of wind turbine owners, as they may, among other things, be paid to make capacity available in the balancing market rather than sell electricity in the spot market.  

Thomas Elgaard sees the positive results in the pilot project as an important first step towards a greener energy market.

"We are very pleased that our models and forecasts are so reliable that Energinet sees a level of security of supply that matches that of conventional power stations. We have, and will continue to, put in a great deal of effort to prove that renewable energy, in addition to being the answer to the green transition, can also contribute to solving the future challenges of balancing the electricity grid. What we have seen in the pilot has been very positive, and it is only the starting point to having more and other types of renewable energy help balance the grid and participate in different markets in the future." 

Initially, the pilot has been based on wind turbines connected to the eastern Danish electricity price area, DK2. So far, wind turbines have participated during the period when Kundby power station has been out of operation and will continue to do so for the remainder of 2020 and into 2021. 

"Going forward, we will add more wind turbines and test several different ancillary services so we may be facing completely new and greener perspectives, where both solar and wind resources can make energy available for more balancing services," says Thomas Elgaard, and reveals that Energi Danmark is already looking at the new market for automatic reserves, aFRR, as the next step.
"We’re moving into brand new territory here, but we believe that, just as Denmark was the first to prove that renewable energy is both competitive and the way forward in the green transition, Denmark can also show the way when it comes to integrating the future huge volumes of renewable energy in the world into the electricity system and electricity markets," states Thomas Elgaard.

Kia Marie Jerichau adds that experience gained in this project is expected to be implemented in the national market designs for ancillary services by the end of 2021. 

"From Energinet’s perspective, we hope to be able to integrate more wind turbines and test several different ancillary services so that we can look into completely new and greener perspectives, where both solar and wind resources can make energy available to more balancing services and ensure the future security of supply".


Contact information:

Kia Marie Jerichau, Energinet: + 45 30 92 30 45

Thomas Elgaard, Energi Danmark: + 45 40 59 59 30



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