Dutch electricity grid is overcrowded - PART III/III

In the final part of the triptych, Wannes Devillé explains what a non-standard grid connection looks like in practice. What are the challenges, the problems but especially the solutions of and for such grid connections? Read more here.

Novar has chosen a non-standard connection via Smart Grid Flevoland's GDS for two solar farms in Flevoland. "Because of all the legal and financial obstacles, a regular connection to a grid operator is still our preference if that option is available," says Wannes Deville, Sr. Grid Specialist at Novar. "But because there is currently not enough capacity on the power grid, we have also found other solutions."

This case involves two of Novar's projects: the Dorhout Mees solar park and Solar carport Biddinghuizen. The solar carport will be built on the parking lot of Lowlands and will cover an area of 35 hectares. There will be a total of 90,000 solar panels that will power 10,000 households or 100 festival weekends annually. 

Dorhout Mees' solar park will be built on an old golf course south of the village of Biddinghuizen. There will be nearly 300,000 solar panels, providing power to 34,000 households per year. "We ended up at Smart Grid Flevoland because Liander did not have a solution for us in the short term. Then we started looking for an alternative so we could import the power, and we found this at Smart Grid Flevoland through their Closed Distribution System."

GDS waiver holder

Smart Grid Flevoland is a subsidiary of ENGIE, says Roeland Nijman, project manager at ENGIE Infra & Mobility and WOF. "You can actually best compare Smart Grid Flevoland, as a GDS exemption holder, to a grid operator such as, Liander and Stedin. Moreover, we have a specific geographically defined area where we are allowed to do this in which we can offer technically specific solutions that best fit the questions of the connected party and the situation on site." 

Currently, four wind farms and a battery farm are connected to Smart Grid Flevoland's Closed Distribution System (GDS). "They are parties that generate energy; there are no parties that purchase energy from us. We have received a specific exemption from the Authority Consumer & Market (ACM) to establish a connection so that they can feed their power into the high-voltage grid. We are obliged as an exemption holder to find out if we can realize a connection for parties like Novar in this area."

The advantage of a GDS is, you can combine solar, wind and storage more easily, Roeland clarifies. "The bottom line is that when you have 80 MVA of connection capacity, you can connect 160 MVA of installed capacity to that, for example, when you have a mix of solar and wind. That means in practice that we can put twice as much power on the same connection with the same capacity." With regular grid operators, this does not happen very often at the moment. They then do so with 160 MVA connection capacity.

Additional transformer

When Novar knocked on Smart Grid Flevoland's door for this non-standard solution, there was basically enough capacity to connect Solarcarport Biddinghuizen, Roeland said. "However, we did not have enough capacity for the Dorhout Mees solar park." Smart Grid Flevoland then began to investigate how they could expand the grid to accommodate both solar projects. "We are going to install an additional transformer for this, and that's very interesting because now Novar's problem is solved, but also for us this offers new opportunities. As I mentioned, you can use the connection twice as heavily when you combine solar and wind, so that's what we're going to do."

In addition to connecting more wind farms, Smart Grid Flevoland will install additional batteries to store and transmit energy to the high-voltage line. "These are the largest battery parks in the Netherlands," Roeland says not without pride. "So you see what effect such cooperation can achieve." The battery parks are connected to the solar panels and wind turbines. "This means in practice that they should not be stopped when there is too much joint capacity. The batteries are mainly intended as a solution to absorb the short-term production peaks and thus flatten the generation profile a bit."

Smart grid

Wannes is also pleased with the collaboration. And there is more positive news, he reports. "Because at Smart Grid Flevoland, a smart grid has been installed between the appliances. You don't find those at regular grid operators. This smart grid allows all systems to communicate with each other on a second-by-second basis. This makes a lot of data available with which we can further optimize and innovate."

When more than the maximum available connection capacity is produced by all connected parties, the party that joined last must regulate back first. In this case, that means Novar may sometimes supply less power. Thanks to the smart grid, this is kept to a minimum. "The projects all have their own supply contracts," Roeland explains. "That could mean that the wind turbines receive a lower kWh price and thus, earn less per kilowatt hour of generation than a new project like Novar's. Because the smart grid allows them to see what is happening from each other, they can make agreements among themselves." 

For example, the connected parties can agree to have the wind farm switch back instead of the solar farm, or to use the battery farms. "And Novar can then reimburse the wind farm or the battery farm for this. That way they can both get more out of it. We have developed a platform for this, so people can use the power grid as smartly as possible. So that's an added bonus."

Standard solution now even easier

Despite the fact that so many advantages can be found with Smart Grid Flevoland's GDS, Wannes maintains that the standard solution is basically easier. "With a non-standard solution, the start-up is much more difficult due to the additional financial and legal procedures. Since this solution is still relatively new, this always raises additional questions for all involved. However, the fact that we have applied this ourselves many times already makes the process somewhat easier for us. We are happy to demonstrate this in the next interview."

Among regular grid operators, there is still a lot of uncertainty and doubt about this non-standard solution, Wannes notes. "However, we believe very strongly in GDSs, because you can use the same grid infrastructure more efficiently and therefore you can generate more energy." There are further benefits; also for society, Wannes believes. "With this, we relieve the regional distribution grid by feeding directly into Tennet's transmission grid. 

Furthermore, the transformers that raise the voltage of the solar farms from 23 to 150 kV at the grid station are normally erected by the regional grid operator, and these costs are socialized across all connected parties. With Smart Grid Flevoland, the solar and wind farms bear these costs themselves. Furthermore, with Smart Grid Flevoland, the losses that occur on the grid are borne by the connected parties themselves. With the regular grid, these losses within the power grid are also paid for by society. So there really is a win-win situation."

Want to know more about grid connections and our congested power grid? Read the other parts in this series of articles here. Or read more about solar carports.