UK GAS-Prices rise on unplanned outage, lower wind output

LONDON, Aug 20 (Reuters) - British wholesale gas prices rose on Tuesday morning due to an unplanned outage at a gas field and lower wind output than the previous day.

* Within-day gas price was 1.75 pence higher at 27.50 pence per therm at 0817 GMT.

* Day-ahead gas price up 1.50 pence at 27.50 p/therm.

* Although the system is slightly oversupplied, there is an unplanned outage and lower wind generation than the previous day, traders said.

* Gas field Culzean is experiencing an unplanned outage which is expected to end on Wednesday.

* Peak wind generation is forecast at 6.4 gigawatts (GW) on Tuesday, less than around 9 GW the previous day but it is seen rising to nearly again 9 GW on Wednesday, out of a total metered capacity of around 12 GW, Elexon data shows.

* Lower wind output typically triggers higher gas-for-power demand.

* "As UK wind power is climbing up to above seasonal normal and peak at mid-week, we expect gas-for-power will be decisive factor to determine if (storage) injections will increase during the day to balance the oversupplied physical market," analysts at Refinitiv said.

* Crude oil prices also rose on Tuesday on optimism U.S.-China trade tensions will ease and on hopes major economies will take stimulus measures to ward off a potential economic slowdown that could hit oil demand.

* The system is slightly oversupplied with demand at around 153 million cubic metres and flows at 157 mcm/day, National Grid data shows.

* Day-ahead gas price at the Dutch TTF hub rose by 0.45 euro to 10.00 euros per megawatt hour.

* The benchmark Dec-19 EU carbon contract up 0.20 euro at 26.76 euros a tonne. (Reporting by Nina Chestney)