(Updates with details)
LONDON, March 19 (Reuters) - Power generation from Britain's wind farms hit a record 14.2 gigawatts (GW) on March 17, National Grid said on Monday.
Wind power represented 34.2 percent of domestic electricity generation at 1430 GMT on Saturday, Britain's power grid operator said.
"2017 was a record year for green energy and it's looking likely 2018 is set to exceed that," said Fintan Slye, director of the system operator at National Grid.
Predicting wind output can be difficult as it depends on wind speeds and power demand, but it is expected to increase this year as more wind farms open.
Industry group Renewable UK forecasts around 2 GW of wind capacity will be added in 2018.
Britain is looking to wind power to help bridge a looming electricity supply gap as old nuclear plants and coal-fired power stations close.
Wind capacity in the country grew by about a fifth in 2017 to around 19 GW, data from industry association Wind Europe showed, as wind farms such as Orsteds Burbo Bank offshore extension and Vattenfall's Pen-y-Cymoedd onshore project opened.
In Britain's most recent renewable subsidy auction last year, the price guarantee given to new offshore wind projects fell below that given to new nuclear generation for the first time. Prices are tipped to keep falling as technology advances.
The previous wind generation record, of 13.8 GW, was set on March 1, when a cold snap gripped Britain and National Grid issued its first gas deficit warning in eight years.
Germany has the most wind capacity in Europe, at around 56 GW, followed by Spain with 23 GW and then Britain, Wind Europe data showed. (Reporting by Susanna Twidale Editing by Alexander Smith and Dale Hudson)