The 'money-saving' advice to use the washing machine at night because it 'costs less' has been explored.
People have been running their washing machine at night rather than during to day as the theory goes that your electricity is cheaper at night. However, for the vast majority of people, this just isn't the case.
Most homes across the country pay a 'flat' rate for electricity - meaning the cost is the same whatever time of day you use it. A few homes are still on a tariff called Economy 7 - a system which does give you seven 'off peak' hours in the day when your electricity is cheaper.