The 207 turbines, which would expand the existing 102-turbine Walney 1 and Walney 2 wind farms, would have a maximum height to the tip of the vertical blade of 222 metres.
A decision letter said that the secretary of state considered the scheme would be consistent with national policy statements which set out a national need for development of new nationally significant electricity infrastructure of this type.
He noted that there was an outstanding objection from the National Air Traffic Service pending the agreement of mitigation measure to protect the interests relating to radar.
But the letter said Davey was satisfied that there was a requirement included in the order which meant that if mitigation was not agreed then the development would not be able to proceed.
In addition, the Isle of Man airport and government were concerned about flights from Blackpool to the Isle of Man as a route overlapped with a section of the southern part of the wind farm.
However, the secretary of state noted that a limited amount of traffic used this route and by the end of 2014 this flight path was likely to be disestablished.
According to the Planning Inspectorate, the application was submitted for consideration on 28 June 2013 and accepted for examination on 22 July 2013. It is the 29th project to be decided under the Planning Act 2008 regime and is the 10th wind farm examined by the Planning Inspectorate to gain development consent.