Of course most of our Mills have been using the green, renewable power of wind or water for centuries! The power generated by a large waterwheel or windmill has some advantages, for example it is still possible to mill, turning sails or waterwheel very slowly, when there is very little wind or water. The direct transfer of energy means that a waterwheel generating say 1 horsepower would require a 10hp electrical engine to do the same work. That said, some mills are using wind and waterpower to generate electricity. Mapledurham Watermill on the Thames near Henley is using an Archimedes’ Screw low-head arrangement; and Heron Mill at Beetham near Kendal is using a sophisticated new turbine.