German spot power prices nearly doubled on Wednesday on slower wind speeds and increasing demand ahead of a cold snap that boosted week-ahead prices.

"Residual load increases in all hours in Germany and most of the Central West European countries due to lower wind output and higher consumption," said LSEG analyst Francisco Gaspar Machado.

German baseload power for Thursday was at 83 euros per megawatt hour (MWh) by 0940 GMT, up 93% from the closing price for Wednesday delivery.

French day-ahead power was volatile in thin volume. At 0940, it was up 77% at 77 euros/MWh, having opened at 80 euros and dropped meantime to 44 euros.

German wind power output was pegged at 26 gigawatts (GW) on Thursday, down from 42.7 GW expected for Wednesday, LSEG data showed.

French nuclear availability remained at 81% of total capacity.

Power consumption in Germany is expected to rise by 4.1 GW day-on-day to stand at 58.5 GW on Thursday. French usage should rise by 1.3 GW to 58.6 GW, LSEG data showed.

Next week's consumption averages were pegged at 60.3 GW and 74.7 GW respectively in the two countries, owing to a resumption of a five-day working week and drops in temperatures of more than 10 degrees Celsius form current levels.

Many households in France rely on electricity for heating.

Along the curve, the new German year-ahead position was 1.5% higher at 93.1 euros/MWh. The French equivalent was untraded, having closed at 88.3 on Tuesday.

European CO2 allowances for December 2024 gained 1.8% to 77.32 euros a metric ton.

More than a million new solar power systems of a capacity of 14 GW were installed in Germany last year, up 85% year-on-year, thanks to a boom in residential solar generation units, industry group BSW said, citing energy regulator data and predicting sustained expansion in 2024.

The country's installed solar capacity amounts to 82 GW, from which weather-driven generation volumes sufficient to cover 12% of annual power consumption were produced in 2023. (Reporting by Vera Eckert Editing by Louise Heavens)