The unit that both gas and electricity are measured in is kilowatt hours (kWh). One kWh of gas is approximately equivalent to leaving a small gas hob burner on for an hour. One kWh of electricity is the rough equivalent of running a washing machine for an hour. Standing charge-this is a fixed amount that you are charged each day, regardless of how much gas or electricity you use. 2  Unit rate-this is the price you will pay per unit (kWh) of energy, so it can fluctuate depending on how much energy you use.