PARIS, Aug 17 (Reuters) - Several European forward curve contracts reached record highs in afternoon trading on Wednesday as gas and carbon contracts climbed and German utility Uniper announced a 12.3 billion euro loss.

The power price surge is connected to a similar rise in gas prices, as well as a large jump in coal future prices, Rystad Energy analyst Fabian Ronningen said.

Around 20 ships are stuck in traffic along Germany's river Rhine, where low water levels have already impeded shipping this summer, after a vessel's engine failure closed part of the waterway, authorities said.

Benchmark German baseload power for 2023 delivery was up 3.1% at 511.50 euros ($519.89) per megawatt hour (MWh) at 1602 GMT.

The baseload German November and December 2022, fourth quarter 2023, first quarter 2024 and full-year 2025 and 2026 contracts recorded new highs.

The French front-year contract also reached a high of 680 euros/MWh, up 11.1%.

The French fourth quarter 2022 contract reached a high of 1,035 euros earlier, while the first quarter 2023 contract traded for the first time at 1,096 euros.

Ronningen explained that the market does not trust EDF to get the nuclear situation sorted. "There's been such a poor output of nuclear in the first seven months," he said.

Even flat-bottomed tourist barges are having difficulty navigating France's Loire river, which is responsible for cooling a combined 11.6 gigawatts (GW) of nuclear supply, as waters are greatly reduced by drought.

European CO2 allowances for December 2022 expiry rose 4.3% to 96.02 euros a tonne.

On the spot side, prices rose as solar supply is expected to drop in Germany and demand is seen up in France.

The German Friday baseload rose 2.4% to 561 euros/MWh.

The equivalent French price gained 0.5% to 555 euros/MWh.

Power from German solar panels is seen falling 2.5 GW to 7.9 GW, the data showed.

Power consumption in France is expected to rise 1.7 GW to 40.2 GW on Thursday, while demand in Germany is set to edge down 450 megawatts (MW) to 56.2 GW, Refinitiv Eikon data showed. ($1 = 0.9839 euros) (Reporting by Forrest Crellin, additional reporting by Vera Eckert; Editing by Robert Birsel and Shailesh Kuber)