* Link to export 5 GW of power to UK
* Chinese firm involved in consortium
By Susanna Twidale
LONDON, Sept 13 (Reuters) - Power grid operators signed a deal on Thursday to develop a 5,000 megawatt electricity transportation system which could export wind power from Ireland to the UK within five years.
The UK's National Grid and Portugal's grid operator REN are working on a feasibility study for the project alongside Dublin-based renewable energy generator Mainstream Renewable Power.
REN is 25 percent owned by China's dominant utility firm State Grid Corp.
"REN believes this memorandum of understanding sets the ground for the study of a potentially groundbreaking infrastructure for the future of European energy highways," REN Chief Executive Rui Cartaxo said in a statement.
Mainstream Renewable Power aims to supply 1.2 GW of power to the UK by 2017.
Ireland is expected to produce more wind power than it needs, leaving room for exports to Britain, which has a target to generate 15 percent of its energy consumption from renewable sources by 2020, compared with around 9 percent last year.
Mainstream said it has already secured an offer for 5,000 MW of grid connection to the UK which is independent of Ireland's existing grid structure.
A spokeswoman for the project was unable to confirm whether the Chinese firm would have any direct involvement in the scheme.
Chinese firms are also bidding to build nuclear power stations in Britain, with two Chinese firms teaming up to take part in the UK's 6-gigawatt Horizon project.