On a beautiful barren stretch of the Scottish Highlands, just south of Inverness, spin 20 brand new 3,300-kilowatt wind turbines. The second these industrial-scale turbines came on stream last month, all Mars UK’s factories and offices became immediately zero carbon. The US confectionary giant negotiated with the UK arm of Eneco, the Dutch utility behind the Moy Wind Farm, to buy 85% of the turbines’ output over the next 10 years. The move follows similar…