The voice of the energy industry A typical domestic household in the UK consumes 3,100KWh of electricity per year, which is 3,100,000Wh, but what does this mean and how does this much energy translate into the appliances and gadgets you use around the home?

Watt v Watt-hour

Watt is a unit of power, and power is the rate at which energy is either produced or consumed. If we compare a 10W lightbulb and a 20W lightbulb, the 10W lightbulb consumes energy at a lower rate than the 20W lightbulb because it needs less energy in order to work.

Watt-hour is a unit of energy. It is the amount of energy an electrical item consumes over a given timeframe. A 20 watt lightbulb in one hour will therefore consume 20 watt-hour of energy.

To conclude, watts are the rate at which energy is consumed, and watt-hour is the amount that’s consumed. The lower the watt, the lower the rate at which energy is used and therefore the less energy that will be consumed over a given period of time.

To give you some practical examples:

• 1kWh is enough energy to boil a 3kW kettle 6 times

• 800W microwave on full power for 10 minutes consumes the same amount of energy as a 40W lightbulb being kept on for 3 hours

• 1kWh is enough energy to watch a 75W TV for 13 hours

• 1kWh is enough energy for 4 hours of gaming