Nestling alongside rows of conifers and wind turbines in a Welsh valley, a pioneering project will materialise this summer that could prove a blueprint for unlocking Britain’s renewable energy potential. The Upper Afan Valley near Swansea is already home to the biggest windfarm in England and Wales, but in July work will begin there on one of the UK’s largest battery storage schemes. Built by Swedish energy company Vattenfall, the facility will involve six shipping