My children will be so pleased! (They did keep telling me so.) Using a dishwasher to do the washing up is greener than doing the washing up by hand.
That is to say, it makes less CO2.
But only if you run the machine when it’s full.
A modern (condenser) boiler can capture more than 90% of the energy in the gas and convert it directly into hot water, so you might think that would be more energy efficient (and produce less CO2) than using a dishwasher. And the dishwasher uses electricity, and more than half the original energy of the fuel is lost in both creating the electricity in the power station and then transmitting it to your home.
But the trouble is that when we wash up by hand we use more water than the dishwasher does, so that uses more gas and more CO2 overall.
The bald summary figures are:
- Wash by hand in cold water: almost ZERO CO2e (but the plates aren’t very clean)
- Wash by hand, using water sparingly and not too hot: 540g CO2e
- Wash using a full dishwasher at 55°C: 770g CO2e
- Wash using a full dishwasher at 65°C: 990g CO2e
- Wash by hand, with extravagant use of water: 8,000g CO2e
For more details, click here: http://www.guardian.co.uk/environment/green-living-blog/2010/aug/19/carbon-footprints-dishwasher-washing-up