French intra-day power prices spiked Monday after a company note said EDF workers would join a planned anti-austerity strike five hours earlier than initially stated, at 16:00 local time (1500 GMT).
State-controlled EDF, which operates all 58 of France's nuclear power reactors and 80% of the hydro fleet, initially said last week its employees would join a 24-hour strike starting at 21:00 local time Monday.
The time at which the strike will end has not changed from 21:00 Tuesday.
Epex Spot intra-day prices were seen jumping to a high of Eur135/MWh in hour 18:00 CET Monday and to Eur115/MWh in hour 17:00.
In the day-ahead auction Sunday, the price for electricity delivered between 18:00 and 19:00 CET Monday settled at Eur123.46/MWh.
France was seen importing power from Spain for most peakload hours Monday, with imports jumping as high as 1.9 GW between 16:00 and 20:00 CET.
France, usually an exporter of power to the UK, was also seen importing from the UK between 06:00 and 17:00 CET, RTE commercial exchange data showed.
But between rush hours 17:00 and 21:00 CET, France was due to export electricity to the UK instead, with the latter keeping a premium over the French market for those hours, despite a well-supplied system.
UK electricity price for delivery Monday at 1700-1800 GMT settled at Eur178.76/MWh in the day-ahead auction on Sunday, according to N2EX.
"The market has a tendency to keep production away from the spot and speculate in the balancing market. The intra-day (Monday) is already very bear trading around GBP97/MWh in hour 1800 GMT compared to GBP125/MWh on the spot," a trader said.
"I don't think that there was an extra need for security as the system margin was well above the demand level and the spinning reserves were up as well," he added.
The announcement that EDF workers were to strike Monday and Tuesday came after the IEG, an industry association representing 158 electricity and gas companies, including EDF and Engie, said November 4 during a previous national strike it would join a new strike on November 24.
"November 4 was a success. Driven by hydro and joined by nuclear and thermal [capacity], 9,814 MW capacity was taken off the grid," union FNME-CGT said in a note on its website.
The union said Tuesday's strike would call for the end of austerity in the energy sector and for a salary increase of Eur200/month for all employees.
Tuesday's expected action follows the national strike organized on November 4 by CGT, which called for workers and citizens to oppose the EU's drive to open state hydro concessions to competition.
On November 4, market participants expected only hydroelectric plants to be affected. But EDF unexpectedly removed from the grid an additional 2.9 GW of nuclear capacity.
This resulted in French intra-day power prices spiking on the day to Eur267.24/MWh in hour 6:00 local time and between Eur110 and Eur190/MWh in the morning peak hours.
