Why doing the washing on a windy day could save you money: Energy firms plan alert system to tell customers when electricity is cheaper Energy firms are to let customers know when it is cheapest to do their washing The year-long trial aims to find out if people will respond to being told which days are 'greener' The Energy Saving Trust estimates that customers can save £250 by using appliances more efficiently The trial aims to find out if people will do their washing on 'green' days when it is windy Windy days have always been the time to do your washing, washerwomen of old hanging out clothes in the breeze so they dried quicker. And that tradition is set to continue long into the future - because putting the washing machine on could be cheaper when it is windy. Energy firms are trying out a system which alerts customers when electricity prices are cheaper because wind conditions mean green power is cheap and plentiful. "Day ahead electricity alerts" send text messages to customers or put an alert of their smart meter so they know to put their washing on. The year-long trial - conducted by Imperial College London, EDF Energy and UK Power Networks - aims to find out whether people are prepared to do their washing, tumble drying, and other electricity intensive tasks on windy days. The researchers have recruited 1,000 people for the trial, which could pave the way for firms to introduce new tariffs that encourage customers to make use of electricity at times when energy is at its cheapest or demand is at lowest. The Energy Saving Trust estimate that customers can save £250 on their energy bill by using appliances differently. Goran Strbac, Professor of Electrical and Electronic Energy Systems at Imperial, said it could save the whole country money and carbon by using electricity more efficiently. "It is crucial that we understand the role that residential consumers can play in the development of smarter electricity systems that will facilitate cost-effective evolution to a low carbon future," he said. But not everyone is convinced the system will save much money. John Constable, Direct of think tank Renewable Energy Foundation, said building wind turbines has already added money to people's bills - and putting washing in on a windy day will not make up for that cost. The Energy Saving Trust estimates that people could save £250 by being more efficient He said: "This sort of research should have started years ago, before the wind policies got under way, and, though interesting, the announcement is a clear case of too little too late. National Grid is already constraining Scottish wind farms off the system at significant cost to the consumer, and the market data shows that Grid is bracing itself to constrain large offshore wind farms in English waters, such as the London Array, Greater Gabbard, and Thanet, to protect the system in the near future. This will be expensive.