The Netherlands has quickly become a solar panel country. In the world ranking we are in the top ten for the highest share of solar power. On some days, around noon, 60 percent of our electricity demand is met with power from our own solar panels.
So good job. But the other side of the coin is that the power grid squeaks and creaks in some places – especially on those beautiful sunny days. The cables and transformer houses cannot handle all that current. Overvoltage occurs.
And then? About 75,000 owners of solar panels see it happen: suddenly the inverter switches off and the feeding back into the grid stops. An automatic built-in protection, otherwise equipment will be damaged. The consumer is missing some income. Not a disaster, but frustrating.
‘Certainly worries us’
It gets worse. At Liander, they expect the re-supply problems to increase. The network operator anticipates that it will become increasingly crowded on the network. “That certainly worries us,” said a spokesperson.
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But how do you know if you suffer from overvoltage? That question turns out to be more difficult to answer than expected.
The problems can also be caused by the installation not being optimally installed, says the spokesperson for Liander. “We notice that, for example, incorrect inverter settings, incorrect connection and use of cables that are too thin cause a premature failure of an inverter.”
Anyone who sees that the solar panels do not supply any power on a bright day can contact the grid operator. This does not always get you further: for example, you sometimes have to prove to customer service that it is not your own installation:
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From pillar to post
“Customers sometimes feel sent from pillar to post. We recognize that too,” says Maarten de Jong. He works at Enexis and is chairman of the national working group on voltage enhancement. So he deals with exactly this problem. “From the grid operator to the installer and back again.”
He explains that a few ‘smart questions’ can provide clarity. Did the person who installed the panels provide sufficiently thick cables? Have you had panels on the roof for years, and now you suddenly have problems because neighbors have also started taking solar panels? If the answer to those questions is yes, then bells should start ringing. “The moment it bothers you and the neighbor also, there is a good chance that it is in the network.”
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New: grid operator will read smart meters
Is it the network or your own installation? That question will soon be easier to answer. Network administrators have recently gained a tool. The Dutch Data Protection Authority has given permission for the remote reading of the voltage in the meter box.
Maarten de Jong of Enexis: “The code of conduct was approved four weeks ago. This means that we can read the smart meters for voltage deviations. This allows us to act more proactively, ie exactly where the problems arise.” In total there are roughly seven million of these smart meters. “It will take some time to sort that out.”
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The problems with voltage increase are common throughout the Netherlands, although some people are lucky: those who live close to a transformer house have less chance of being switched off. People with more than fifteen solar panels also run slightly less risk because they often have a 3-phase inverter that can distribute the power.
And do you live in a new neighborhood? Then you are basically fine. “In new housing estates, we will of course immediately lay enough cables to transport all solar power.”
Not yet in many other neighborhoods. It is expected that in the coming years more panel owners will suffer from overvoltage on the grid. De Jong shares a graph showing that the number of solar panels has increased fivefold in a short period of time. The number of stress complaints has also increased. “It is expected to increase as more and more people purchase solar panels.”
One in three streets must open
So work on the shop. The Netherlands can wet its chest: one in three streets has to be broken up. “These are really transition pains,” says De Jong. “We will be working on strengthening the electricity grids for decades to come.” This mainly concerns the construction of transformer houses and the laying of thicker cables.
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The grid operator emphasizes: the energy transition affects us all and is something that everyone encounters. It applies to the large generators – large solar parks for which there is no space on the grid – but sometimes also to consumers.
The adjustments to the electricity grid also lead to resistance. Like in Amsterdam, where local residents revolt because the electricity houses would spoil the view.
‘It rubs at this stage’
And then grid operators also run into other issues, such as lengthy permit procedures, a shortage of people and a shortage of equipment. This concerns cables and parts of transformers that are not available, says a spokesperson for Liander. Delays in residential areas are mainly caused by the difficulty of finding a suitable location for medium voltage areas† “In short: it rubs off in this phase of the energy transition.”
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The high-voltage grid is also full
Grid operators ensure that the voltage at people’s homes is supplied at 230 volts. This so-called low voltage, which applies to the low-voltage grid, is intended for electrical appliances in the house.
Large amounts of electrical energy are transported via the medium-voltage grid (10,000 or 20,000 volts) and then via the high-voltage grid. TenneT manages this high-voltage grid in the Netherlands and large parts of Germany. It concerns 110,000 volts and above.
This high-voltage grid is also sometimes full, like in Flevoland† A spokesperson for Liander: “If the highway, TenneT’s high-voltage grid, fills up, there is a good chance that the provincial and local roads will also fill up: Liander’s medium and low-voltage grids. We are inextricably linked.”
Consumers are not switched off, but it is possible that when large amounts of energy are generated, the inverter of the solar panels switches itself off temporarily. “Supply through the net will then continue to take place.”
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Smart devices can help
Can you, as a consumer, do something yourself? Yes, of course. You can help by keeping the voltage on the low-voltage grid between 207 and 253 volts, for example by charging devices.
Because that’s what it’s all about: solar panels, heat pumps, electric cooking and electric transport are increasingly reaching these limits: for example, grid operators have to work in the winter and in the morning and evening because there is a threat of undervoltage – then we will not generate electricity , but we actually use a lot.
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“You have all kinds of smart devices these days,” says Maarten de Jong. The most important is the electric car. The chance that the inverter will fail is a lot smaller if you charge the car during sunny hours.
Turn on the washing machine during the day
“I’m at a supplier that offers smart charging: I can push a button that it only charges the car when the price is low, which is roughly the same as when a lot of energy is being processed.”
It is also better to turn on your washing machine during the day. “And your electric boiler. Then your inverter doesn’t have to switch back.” For example, there are even more possibilities.
De Jong just wants to say: there is still a lot to gain in matching supply and demand. “Weightening the grid by installing thicker cables is possible, but it is expensive. And it is social money that we spend. In that sense it is ultimately a social problem.” Or a challenge, if you will.
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