LONDON: British wholesale gas prices rose on Monday as weak wind output and demand for air conditioning amid hot weather boosted gas-for-power generation.

The day-ahead contract was up by 1.50 pence at 21.00 pence per therm by 0905 GMT.

Within-day contract rose by 0.85 p to 20.85 p/therm.

After prompt contracts rose to an over four-month high last week, supported by gas prices in continental Europe, stronger US Henry Hub prices and increased gas-for-power demand, prices continued to climb on Monday.

"Gas-for-power consumption, which increased by the end of the last week, should remain firm supported by low wind generation and hot temperatures," Refinitiv analysts said in a morning note.

Peak wind generation was forecast at 4.9 gigawatt (GW) on Monday and 4.4 GW on Tuesday out of 18 GW total metered capacity, Elexon data showed.

Gas-for-power demand was forecast at 55 million cubic metres (mcm) on Monday, 4 mcm up compared to Friday, and set to rise to 59 mcm on Tuesday, Refinitiv data showed.

UK gas system was 10.3 mcm oversupplied, however, with demand forecast at 148.6 mcm and supply at 158.9 mcm, National Grid data showed.

The ovresupply was due to an increase in flows from Norway and a drop in exports of gas from Britain to Belgium.

Howeverm a number of scheduled Norwegian outages are expected to reduce flows from later this week. On the curve, prices also rose.

The fourth quarter 2020 contract was 0.65 p up at 31.25 p/therm.

The day-ahead gas price at the Dutch TTF hub was up 0.35 euro at 7.35 euros per megawatt hour.

The benchmark Dec-20 EU carbon contract was up 0.65 at euro at 27.07 euros per tonne.