Electricity consumption of society is usually at its lowest at night and at weekends. Consumption peaks often take place on weekday mornings and afternoons, during which time it is worth avoiding energy usage. This is especially important when using Exchange Electricity where the price of electricity varies by the hour according to the market price of the power exchange. It is advisable to set the timer for domestic washing machines to operate at night-time, and it is sensible to charge an electric vehicle during the night. It is also worthwhile to have underfloor heating and other electrical heating appliances on during periods of low price levels. And perhaps go to the sauna only at weekends.