Solar park The Sun Willow commissioned

Stan Reinders, construction supervisor at GreenTrust, is closely involved in the project. He previously supervised the construction of Den Tol wind farm. “It’s nice to now also help realize the solar park,” he says. “Because I know the project well, we can move quickly and make smart choices.”

GreenTrust is supporting Windunie and the farmers involved in this progressive initiative, including in the tendering and construction supervision. Construction is almost complete – the solar farm is about to enter the testing phase.

Efficient and forward-looking

Cable pooling is a smart way to get more renewable energy on the grid and, in the process, put less strain on the power grid than if each generating plant had its own grid connection. Sun and wind complement each other well: often it blows when the sun is not shining, and vice versa. By using the wind farm’s existing cables, the existing capacity is optimally utilized.

“Normally you build either a solar farm or a wind farm,” says Stan. “But here we combine them. That requires good cooperation as well as technical coordination.”

Customized Energy

Solar Farm De Zonnewilg is literally located between the nine wind turbines of Wind Farm Den Tol. To avoid overloading the grid, an energy management system is needed. That system allows the solar farm and the wind farm to “talk” to each other and match their power output to what the grid connection can handle.

“Most of the time, both the solar farm and the wind farm can put their maximum available power into the grid connection,” Stan explains. “But at peak times you have to downshift. This system controls that automatically.”

Pilot operation of the solar farm will start as soon as the energy management system is fully set up. Energy meters have been installed at various locations in the park, connected by fiber optics. If everything works as planned, the 27,000 solar panels could start delivering full power to the grid.

Practical collaboration

In this project, GreenTrust is working closely with Windunie and the landowners, including local farmers. That cooperation is going extremely well, according to Stan: “The farmers think practically. If something needs to be done or decided, they are there right away. That makes working together pleasant and efficient.”

The knowledge Stan gained earlier during the construction of the wind farm is of great value in setting up the new system. “It is important to know not only what is there, but also why certain choices were made. Those insights make all the difference in implementation.”

Looking ahead: hydrogen

Developments in Netterden are not standing still. There are plans to also produce hydrogen at the wind farm. The energy management system is already prepared for this next step. “If you develop something, it has to be future-proof,” says Stan. “We take that into account from the beginning.”

Wind farm Den Tol and Kuster Energy (gas station operator and fuel supplier in the border region of the Netherlands/Germany) have plans to build a hydrogen plant at the wind farm in 2027. This plant will convert locally generated power from wind and solar energy into green hydrogen. The hydrogen produced is intended for use in construction, local industry and regional transportation. By producing hydrogen at times of abundant wind energy, the project contributes to reducing grid congestion and making the region more sustainable. In this broadcast from Regio8, Eelco Bots of Windpark Den Tol talks about future plans.

Solar Park The Sun Willow

Location: Netterden, municipality of Oude IJsselstreek (Gelderland)

Initiators: Windunie and a group of local farmers

Number of solar panels: about 27,000

Expected annual solar farm output: ± 14,000 MWh (enough for ± 5,000 households)

Expected combined output (solar + wind): ± 90,000 MWh per year

Details: solar farm is linked to Den Tol Wind Farm via cablepooling