How do I know if green electricity is really green? Currently, the only domestic tariff available which has a Certified Green Energy label is Good Energy's 'Good Energy' tariff. Its electricity mix is 100pc renewable and comes with a pledge from the supplier that it will "invest in renewable heat generation projects that will benefit local communities," as an additional environmental commitment. In the UK average fuel mix, 11.3pc is from renewable sources. Some 38.4pc is from coal, 27.7pc is from natural gas, 20.6pc is nuclear and 2pc is classed as 'other', according to the Department of Energy and Climate Change. Good Energy's fuel mix Customers can check the fuel mix on their energy bills to see how much of their energy is from renewable sources. Suppliers should also list this information on their website. EDF Energy's fuel mix, for example, for each of its tariffs is listed below. Green energy providers supply their customers through the National Grid - as does every other UK supplier. This means all electricity comes from the same place, regardless of whether it is green or not. A Good Energy spokesman said the National Grid is like a "dirty pond" of electricity. All the electricity produced in the UK goes into this pond. "Good Energy promises to match all the electricity our customers use over a year with electricity sourced purely from renewables," he said. So while all the electricity used by customers comes from the same pond, we are adding electricity from renewable sources into the pond. Of course, the more renewable energy we pour into the pond, the cleaner it will become. The National Grid delivers electricity from suppliers to consumers So the electricity all customers receive in their homes is exactly the same, regardless of their energy provider or tariff. However supporting green providers ensures the amount of renewable energy going into the National Grid increases, improving the environmental impact of the whole market. Do you have a question about energy, or any other household bills?