In 2011, Elizabeth Gass sold some 230 acres of her Fairfield estate at Hinkley Point for about £50 million.
There are conflicting reports about whether the land was for the development of nuclear power or a wind farm.
EDF initially said it would delay a final investment decision until September 2016.
On the same day, the Secretary of State for Business, Energy and Industrial Strategy Greg Clark announced that the government would delay its decision until the autumn of 2016 to "consider carefully all the component parts of this project", including Britain's national security.
In March 2014, the Court of Appeal allowed An Taisce, the National Trust for Ireland, to challenge the legality of the decision by the Secretary of State for Energy and Climate Change to grant development consent.
Wylfa is expected it will come in around £77 per megawatt hour.
On July 2017, the estimated construction cost had climbed in two years to £19.6 billion and was revised to £20.3 billion accounting for the fifteen months estimated delay cost, with a start date of between 20.
July 2008 saw the start of early enabling works with the construction of a car park for a ground investigation programme.
In January 2014, an initial critical report was published, indicating that the UK government's plan may well constitute illegal state aid, requiring a formal state aid investigation examining the subsidies.
Franz Leidenmuhler (University of Linz, a specialist in EU state aid cases and European competition law), wrote that "a rejection is nearly unavoidable.
Lord Justice Sullivan said that "he did not venture that it had a real prospect of success, it was desirable that the court should give a definitive view as to whether there should be a reference to the Court of Justice of the European Union and, if not, on the meaning of the Directive".