The output of Finland's newest nuclear power facility, Olkiluoto 3, has been significantly cut back because electricity has become too cheap, according to the plant's owner, Teollisuuden Voima (TVO).
"Electricity production must also be profitable for nuclear power plants, and when the price is particularly low, there may be situations where output is limited," TVO communications manager, Johanna Aho, said.
Early on Wednesday the market price for electricity dropped below zero cents per kilowatt-hour (kWh) and for hours after that the price was only 0.3 cents per kWh at its highest, according to the country's grid operator, Fingrid.
The Olkiluoto 3 nuclear reactor in Eurajoki, southwest Finland, started regular electricity production in mid-April, about 14 years behind schedule.
Generally, the amount of electricity generated in Finland is regulated by increasing or decreasing the amount of hydroelectric power that is used. However, due to flood conditions in northern Finland, reducing hydroelectric-generated electricity is challenging at the moment.
According to Aho, cutting back on nuclear power production due to excessively low electricity prices is very rare, but not unheard of.
Janne Kauppi, an energy markets advisor at Finnish Energy, agreed with that sentiment.
"There haven't been many situations where nuclear power output has been regulated specifically because of low prices," Kauppi explained.
For example, production levels are more regulated in places like France, where nuclear power is responsible for providing the majority of the country's electricity.
"When prices go negative on the electricity market, basically anyone who can adjust their production will do it, so that they don't have to pay for their own production," Kauppi noted.
Nuclear power production in Finland may increasingly need to be regulated due to such situations.
Around 500 megawatt-hours of new wind-generated electricity went online in the country this year alone. Those kinds of developments mean that in future, electricity market prices could dip into negative numbers more often than they currently do.
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