UK GAS-Prompt prices rise as low wind power output boosts gas demand

May 30 (Reuters) - Prompt British wholesale gas prices rose on Wednesday morning as lower output from the country's wind farms led to higher demand for gas from power stations.

* Within-day contract up 1.50 pence at 59.50 p/therm by 0755 GMT

* Day-ahead gas price up 1.40 pence at 59.50 p/therm

* Peak wind power generation is forecast at 3.7 gigawatts (GW) on Wednesday, falling to below 1 GW on Thursday, National Grid (LSE: NG.L - news) data showed

* Gas system undersupplied by 7.4 million cubic metres (mcm), with demand forecast at 172.6 mcm and flows at 165.2 mcm/day, the data showed

* "Stronger gas-for-power demand forecast for today - up 10 mcm from yesterday - and small adjustments in UKCS (UK Continental Shelf) production are among the reasons for the undersupply," analysts at Thomson Reuters (Dusseldorf: TOC.DU - news) said in a daily research note.

* Gas-fired power plants provided 57 percent of Britain's electricity on Wednesday.

* Further out on the curve, the June contract was up 0.45 p at 58.00 p/therm.

* Day-ahead gas price at the Dutch TTF hub up 0.23 euro at 22.83 euros per megawatt-hour.

* Benchmark Dec-18 EU carbon contract down 0.20 euro at 16.10 euros per tonne. (Reporting By Susanna Twidale; editing by Nina Chestney)