This is a story about energy. Energy is a utility, a basic necessity for homes and business. It is also a big investor and a major employer. But electricity - and energy costs in general - has become a major issue for householders, for the competitiveness of manufacturers and for exporters in every country of Europe. And Europe – itself a bit of a dog-whistle issue in the UK - has, as we saw just the other weekend, become a very hot topic indeed, writes Angela Knight, chief executive of industry body Energy UK.