PARIS, Sept 11 (Reuters) - European forward electricity prices extended gains in wholesale trade on Wednesday, keeping momentum from the previous session, while day-ahead prices were lifted by a forecast fall in renewables generation and French nuclear power supply.
* Germany’s CAL’20 year-ahead baseload power contract , the European benchmark, hit a high of 51.25 euros ($56.50) a megawatt hour (MWh), its highest level since August 5, before retreating to 50.90 euros/MWh, up 0.7% by 0911 GMT.
* The equivalent French contract for 2020 surged to an eight-week high of 55.10 euros/MWh, up 2.8% from the previous session.
* European CO2 permits for December 2019 added 0.8% to 26.95 euros a tonne.
* Hard coal for northern European delivery in 2020 ticked up 0.1% to $68.60 a tonne.
* At the front end of the curve, French contracts for October, November, December, and delivery for the fourth quarter added strong gains on concerns of possible reactor closures in France.
* Utility EDF said on Tuesday it had discovered problems with the weldings and other components in some of its nuclear reactors.
* Separately, French nuclear regulator ASN said on Wednesday that it had put EDF’s Flamanville 1 and 2 reactors under increased surveillance following a series of shortcomings in maintenance and contractor oversight.
* In the day-ahead market, contracts rose on Wednesday on the back of a forecast drop in renewables and nuclear power generation in France.
* The French over-the-counter baseload power for Thursday delivery soared 14.3% to 37.75 euros/MWh.
* The German day-ahead contract rose 10.7% to 38.50 euros/MWh.
* German wind power supply is expected to fall by 750 megawatts (MW) day-on-day on Thursday to 11.7 gigawatts (GW), Refinitiv data showed.
* German solar generation will drop by 730 MW to 5.1 GW.
* In France, nuclear reactor availability fell by 2.4 percentage points compared with the previous day to 69% of maximum capacity.
* On the demand side, consumption in France is forecast to ease by 460 MW on Thursday to 46.8 GW, Refinitiv Eikon data showed. German power demand will rise by 140 MW to 63.3 GW, the data showed.
* Average temperatures will rise in Germany and France on Thursday by 2.8 and 2.4 degrees Celsius respectively.
* In eastern Europe, the Czech day-ahead baseload power price , which mirrors the German contract, added 12% to 42 euros/MWh. The year-ahead position was untraded at its previous close of 54.45 euros/MWh. ($1 = 0.9071 euros) (Reporting by Paris Newsroom Editing by Gus Trompiz)