These examples of sunflower photovoltaic technology provide enough energy for the average house all year round. They move and tilt to the suns path, they work in sunny and cloudy weather and close automatically when too windy. Their cost today is between €20,000 and €30,000 and according to Swansons law they will be the size of a small table, the cost of a computer and on each rooftop in the next ten years to produce virtually free energy. Now there’s some food for thought!!