British Gas owner Centrica has signed a £6.2bn ($8bn) mega deal with US fossil fuel producer Delta Midstream, in a welcome boost for the UK’s power supplies. The agreement IS for 1m tonnes per annum of liquefied natural gas (LNG) for 15 years, and means Centrica will take delivery of around 14 LNG cargoes per year. This could provide enough energy to heat five per cent of UK homes on an annual basis. Supplies will be shipped from Delfin Deepwater Port, located 40 miles off the coast of Louisiana, with first operations expected to commence…