A light gray mass hangs over the port area of Vlissingen. It has four short legs at the bottom and three bulbs at the front – there’s not much to see. There are eight black drawers in the block, and in those drawers are rods of lithium, iron, and phosphate. It all weighs about three and a half tons.
A winch lowers the block atop some metal beams, the same shade of light gray. Three men take it and push it until it lands in the right place. Four screws through the legs, then another block. And that’s 168 times. A few hundred wires in it, an inverter and a transformer, and you have the largest battery in the Netherlands. Starting in the fall, this battery should help the transition to sustainable energy, despite the overcrowding of the power grid.
Paul Gillock taking a photo of work with his phone. “Show it to my colleagues.” SemperPower, the company he works for, owns the battery, but Geluk has never visited the site in Zeeland before.
The three-year-old company from Amsterdam leaves the installation of the battery modules to the main contractor. And SemperPower has nothing to do with the electricity that will soon flow through it.
“We will soon be leasing the battery to different parties,” Gelock explains. One third is for the Essent, and he is not allowed to say anything about the other two thirds. For a monthly fee, together they have 63 megawatt-hours of energy storage at their disposal, enough to power nearly a hundred thousand homes for two hours.
fluctuations on the net
Providing power to families is not the purpose of the battery – it is to prevent blackouts. correct.
Energy suppliers like Essent predict a day in advance how much power they will need every 15 minutes and buy power on that basis from power producers like EPZ, owner of the Borssele Nuclear Power Plant. Fifteen minutes before the power supply, there is a correction moment in which the power producers categorically indicate how much power is coming and the power suppliers tell them how much they need.
After that quarter of an hour, unexpected differences emerge from predictions. A cloud passes over a solar park, a train stops, and a windmill crashes. These differences increase or decrease the frequency of the power grid, which should remain around 50 Hz. Too big deviation will cause power outage. To prevent this, TenneT’s high-voltage grid operator has what’s known as a frequency containment reserve (FCR), also known as primary reserve capacity. They are holding a portion of the space that power producers have to generate free electricity for TenneT to call upon. They should be able to deliver more or less power within thirty seconds. They receive a daily allowance and some money for electricity.
The ability to get in and out quickly is critical to being competitive in the FCR market. Nuclear power plant can’t do it, but gas power plant can do it, and battery is better. Thus, a battery tenant like SemperPower battery can make a profit with Tennet’s fast standby. The downside: Tennet only needs 111 megawatts this year to absorb such fluctuations, and there are already more than enough batteries for that.
Then there’s the slightly slower automatic frequency recovery reserve (aFRR), which TenneT calls if longer divergences occur. The winds rise, the clouds disappear unexpectedly, and a chemical plant stops working. Those who contribute to aFRR should be able to provide or receive additional energy within five minutes. This market also has a downside: To participate, the party must be able to supply power for 24 hours—not suitable for a battery that can only run at full capacity for two hours. The rules will change later this year, and until then the batteries can contribute quite a bit to this “secondary reserve capacity.”
Finally, there is the imbalance of “voluntary trading,” where energy providers can sell or buy electricity to keep supply and demand equal. Essent will also do something similar with the Zeeland battery: If power demand drops for a while, the power supplier puts away the excess capacity to fill in the gaps later. Compare that to a greengrocer putting some lettuce in the fridge when there are fewer customers than expected.
This “imbalance market” isn’t all either, Books consulting firm CE Delft in late 2021 in the Battery Storage Study. Batteries are only expected to be able to turn a profit there from 2030.
So it seems that fixing the peaks and troughs on the power grid yields little, yet the battery companies are betting on it. A combination of, say, FCR and aFRR and voluntary trade could be profitable, CE Delft calculates. By 2030 there will be room in the “unbalanced market” of a maximum of 2 gigawatts, so more than sixty batteries like the one that SemperPower is now installing in Vlissingen.
The more popular sustainable energy becomes, the higher the volatility, happiness you can expect. It is simply more difficult to predict the power output of a wind or solar park compared to a power plant. “The outlook is improving, but green electricity is growing faster.” The market for volatility-absorbing parties is also growing.
Correcting imbalances is helpful, but the real challenge lies elsewhere. Sustainable electricity supplies are predictable but come at an inopportune time. The wind does not keep up with the demand for electricity, and on a winter day the sun may shine during the day, but electricity is needed only when it is dark and the heating is turned on in the house.
It is already common for energy prices to be negative due to an excess of sustainable energy. Dutch solar panels could easily supply 14 gigawatts in an afternoon if only 12 gigawatts were needed. Selling energy abroad is not enough in times like this to be able to sell everything. Sometimes wind or solar parks have to be closed temporarily. Shame – there is sustainable energy, but it has nowhere to go, while other times there is a shortage. If this continues, security of supply will be at stake in 2030, TenneT warned at the start of this year.
Batteries seem like a simple solution: to collect energy when the sun is shining and the wind is blowing and then release it again when it is dark or windless, or even store it in the summer and distribute it back in the winter. But it’s not far away yet. CE Delft analysts expect a meaningful role for batteries as a “balancing act” in the energy market only after 2030.
“Small peaks also need to be resolved, and the batteries are already ready for that,” says Dorine Hugenholtz. Her graduate research at TU Delft was on this subject, and she is now working on battery projects at energy supplier Vattenfall. “Batteries are not yet suitable for hills of weeks, months, or seasons.”
The two hours during which the battery in Vlissingen can operate at full capacity is too short to provide a completely sustainable power supply. Deploying dozens of these battery farms to make a bigger battery isn’t the answer either, because all those batteries are very expensive. SemperPower has invested around 27 million euros in the 168 light gray blocks that are now being installed. And a week’s worth of battery full power won’t make any money.
According to Hugenholtz, we will have to wait until there is more sustainable energy and until the batteries become better and cheaper. It also hopes that using the electricity grid will become cheaper. There is no separate category for batteries, so we pay the same amount as a big manufacturer. This is the main bottleneck in starting energy storage.”
Pay to call
As if things weren’t complicated enough already, there is also grid congestion, which hinders higher energy storage. “A traffic jam on the power grid,” Gelock describes the problem. It’s not about a lack or excess of power, it’s about a cable that’s too narrow for all that electricity to pass through.
A SemperPower spokesperson says the connections SemperPower will receive will take up a “huge chunk” of the space that local network operator Stedin still has left. “After that we have very little strength left.”
So it is no coincidence that the SemperPower battery is located in the port area of Vlissingen, near a row of windmills, a nuclear power plant and a gas-fired power station. It’s one of the few places that do that The network congestion map is still completely white. “Everything here is set up to move clumps of electrons,” Gelock says.
Steden’s spokesperson says other battery companies would love to have such a connection. “When North Brabant and Limburg announced things were going to shut down, we had several battery teams from the south asking us for space on the power grid.” Stedin no longer gives network connection without ifs or but SemperPower also comes here.
Read also: Grid congestion as a revenue model: Firms playing an important role in the energy transition
Geluck stresses that the busyness of the power grid need not be an obstacle. “Because of congestion, municipalities have become reluctant to issue permits for batteries, but with the right agreements, a battery puts no additional strain on the power grid at all.”
Acting in a crowd-neutral manner is what it’s called in jargon. This means that the battery is not allowed to do anything during traffic jams. Network managers like Stedin can make up for this, but according to Geluk, this isn’t necessarily necessary. “If our battery has been down for a month, it barely degrades and we can use it for a month longer at the end of the trip.”
The battery can help take the pressure off the power grid. When placed in the right place and charged and discharged at the right time, the battery can provide energy that would otherwise not fit through the cable. According to CE Delft, this is most often part of the solution to the traffic congestion problem, and Geluck agrees. ‘Power grid promotion is number one.’
While the largest battery in the Netherlands is being prepared for use, other batteries are about to catch up. Twenty meters away, on the other side of the fence around the construction site in Vlissingen, SemperPower has already made preparations for an installation with a capacity of 68 MWh. Meanwhile, Delfzijl’s Giga Storage says it’s working on Europe’s largest battery. Then there are the promises of new types of energy storage that could shatter all those records again, like underground cavities filled with compressed air or a liquid-flow battery.
Read also: The power grid can be kept in balance with huge batteries
The light gray blocks will be in the port area of Vlissingen for about ten years. They lose a few percent of their storage capacity each year and after about ten years are “too small” to use here. Then they go to other places where this is less of a problem, to eventually be recycled.
Happiness does not yet know what will replace it in ten years. “Developments are going very fast now, by then there will probably be something new.”
A version of this article also appeared in the newspaper on June 5, 2023.
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