Ryoko Scott's living room is lined with candles as her family huddle into one room to spend the next few hours together.
They've already made themselves cups of tea and have now switched off all their electrical appliances, including their computer and the lights.
Ryoko and her husband Mark, both 53, and their 14-year-old son, will all wait to turn their oven on to cook their evening meal and hold off on carrying out any chores.
