Crunch Time For Sweden’s Grid as Nuclear Repairs Set to Start


The traditional repair season for Sweden’s reactors will be anything but normal this summer as the grid manager is forced to take unprecedented measures to keep the lights on.

What used to be routine during the summer is getting more problematic for Svenska Kraftnat. After utilities from Vattenfall AB to EON SE permanently shuttered half of the nation’s reactors in the past 20 years, there is just not enough spare capacity left in the south for several big units to go offline at the same time without also restricting power flows.

For the first time in a decade, the network manager will curb exports to neighbors during planned maintenance. The utilities will bus hundreds of specialists across the country to replace everything from switchgears to cooling intake mussel-filters at the plants.

From May 22 until at least June 20, when three reactors are offline, Svenska Kraftnat will limit power flows to and from Norway, Denmark and Finland as well as internal transfers from northern to southern Sweden.

Crunch Time For Sweden’s Grid as Nuclear Repairs Set to Start

“The capacity situation has become severely strained in the south of Sweden during the summers,” said Henrik Svensson, who runs Uniper SE’s oil-fired reserve plant on the southeast coast. “We have even started to generate more power in the summer than during the winter.”

The plant has a contract until 2025 with the grid to provide reserve power from November to March. It’s available to the market for the rest of the time. Last year it started four times in May and June when prices spiked, before the grid manager signed a new temporary deal in July. No agreement has been signed for this summer.

According to Ulf Moberg, technical director at Svenska Kraftnat, the nation’s grid was built around the stability of the nuclear plants. Fewer of them will impact the ability to transfer power, and especially flows from the wind and hydro-rich north to the south where most people live.

Crunch Time For Sweden’s Grid as Nuclear Repairs Set to Start

Reduced capacity through Sweden also contributes to significantly higher prices in the entire southeast Nordic and Baltic region. Last year’s average power price was 64% higher in the south than in the north.

“The big geographical price difference is a symptom of a system depleted of plannable resources,” said Carl Berglof, a nuclear and power grid expert at industry group Swedenergy. “When you shut down nuclear reactors and other planable production units it has consequences.”

To address the problem in the longer term, the Swedish government announced on April 14 plans for a new law aimed at reducing the time it takes to build new power lines by half. Still, according to the grid manager, new cables are not enough, there needs to be more stable production units to resolve the problem.

Crunch Time For Sweden’s Grid as Nuclear Repairs Set to Start

On Sunday, Teollisuuden Voima Oyj will kick off the region’s maintenance halts at its Olkiluoto-1 unit in Finland. Vattenfall will end the year’s planned work at the Forsmark-3 reactor on Oct. 17.

©2021 Bloomberg L.P.

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