Big batteries and EVs to the rescue again as faults with new nuclear plant cause chaos on Nordic grids

The newest and most powerful nuclear reactor in Europe that was delivered more than a decade late and nearly four times over budget is also proving to be a headache for grid operators now that it is finally up and running.

On Sunday, the 1,600 megawatt Olkiluoto 3 nuclear reactor tripped again, the latest in a series of faults and outages that have plagued the new facility and caused the market to reach out for back-up power to fill the gap.

Olkiluoto owner TVO says the reactor tripped on Sunday due to a turbine malfunction in the generator’s seal oil system. “The repair is taking longer than expected, and based on the current information, the plant is estimated to return to electricity production in approximately two days,” it said in a statement.

It’s not the first time the unit has failed. In October, it was forced to reduce power suddenly when one of the reactor’s control rods unexpectedly dropped into the reactor. 

Its sister reactor, Olkiluoto 2, was off line for three weeks due to a faulty water-cooled rotor that had to be replaced and will run for months at reduced output because of the fear of failure.

But on Sunday, when the entire 1,600 MW capacity of Olkiluoto 3 was taken out of the system with no notice, it had a big impact on the grid, sending frequency plunging to 49.55 Hz, well outside the normal band.

“Olkiluoto is starting to compete with the Swedish nuclear power plant, Forsmark, for being the leading cause of major (loss of generation) disturbances in the Nordic power system,” writes Andreas Barnekov Thingvad, a Denmark-based trading systems director at battery company Hybrid Greentech.

He says his company contributed to the market response to stabilise frequency (see graph above) and the grid with its portfolio of batteries and virtual power plants, including electric vehicles.

Olkiluoto was finally connected to the grid last year, at an estimated cost of €11 billion ($18 billion) compared to the original budget of €3 billion. That cost blowout forced its developer, the French company Areva, to be bailed out by the French government.

When it did come online, nuclear boosters in Australia hailed it as being responsible for a steep fall in electricity prices. They failed to mention the fact that the reactor was more than a decade late, and Finland was forced to turn to highly expensive Russian gas in the interim to make up the shortfall.

Indeed, TVO, the reactor owner, says now that the new reactor has been commissioned, there is often too much production on the Finnish grid, and the reactor has to be dialled down, or curtailed, in much the same way that renewables often are. It is still not allowed to run at full capacity.

“The electricity system in Finland faces on an increasingly frequent basis a situation where more down-regulating production capacity is needed because there is too much production,” TVO notes.

The new reactor has also spent large periods off line (see the graph above from TVO’s most recent interim report). Its annual outage was supposed to last 37 days, but stretched to double that, to 74 days. TVO blamed “defect repairs and technical problems with inspection equipment took more time than had been planned.”

The point of this story is to highlight another bit of nonsense from the nuclear lobby, who like to claim that renewable sources such as wind and solar require back up, while nuclear does not.

That is simply not true, and the world’s big investment in pumped hydro in the 1970s and 1980s was principally designed to provide back up to nuclear reactors then in vogue. Ontario has ordered some of the world’s biggest batteries to support its nuclear fleet, most of which will be offline for several years for upgrades and maintenance.

Thingvad noted the multiple recent outages that had occurred in both the Finnish and Swedish nuclear reactors over the last few months:

• – On November 17th, at 15:25:51, Olkiluoto 3 had another turbine failure, tripping all 1600 MW of generation and causing the Nordic system frequency to drop to 49.59 Hz. The failure is expected to last several days.
  
  – On September 3rd, Olkiluoto 3 experienced a fault that caused it to drop 640 MW, leading the Nordic frequency to fall to 49.77 Hz.
  
  – On June 10th, Forsmark Block 3 experienced a reactor trip of 1172 MW, causing the Nordic system frequency to drop to 49.61 Hz.
  
  – On June 3rd, 2024, Olkiluoto 3, with 1600 MW, suddenly tripped due to a turbine malfunction. The Nordic system frequency dropped to 49.58 Hz.
  
  – On May 13, 2024, the Forsmark Block 1 nuclear power plant in Sweden, which has a capacity of 1 GW, tripped due to a grid failure. Forsmark experienced multiple outages – each of at least a gigawatt – in 2023.
• 
  The scale of such outages would be significant in a grid like Australia, where the biggest single unit – at the Kogan Creek coal fired generator in Queensland – is 750 MW.

If, as the federal Coalition proposes, it wants to put in units sized at a gigawatt or more, then the market operator will have to invest in more standby capacity in case of the inevitable trips and outages.

The bigger the unit, the more back up power that is required. Wind and solar may be variable, but those variations are easily and reliably predicted. The sudden loss of a 1,600 MW facility is not.

The Australian Energy Market Operator has already made clear that its biggest headache is managing the unexpected outages of big generators, such as the ageing and increasingly unreliable coal fired power stations that the federal Coalition wants to keep open while it waits for nuclear to be rolled out and commercial SMRs to be invented.

“The repeated outages at Olkiluoto and Forsmark nuclear plants are a stark reminder of the critical need for grid resilience and diversification in our energy systems,” noted Eric Scheithauer-Hartmann, a German-based energy executive.

“It’s encouraging to see companies like Hybrid Greentech stepping up to support the Nordic power grid with advanced battery storage and intelligent energy solutions.

“As we continue to face challenges with traditional power generation, investing in smart grid technologies and renewable integration isn’t just beneficial—it’s essential for maintaining stability and meeting future energy demands.”