Six energy suppliers and Good Energy Group PLC have signed up to the guidelines so far and Ofgem has welcomed their participation. Ofgem has now asked them to start work immediately on setting up an accreditation scheme that will enable householders and small business customers to easily compare green offerings based on the carbon emissions they reduce. The scheme will be run by an independent body.

Ofgem will work with the suppliers to set up the accreditation scheme by summer 2009. Ofgem envisages that information on accredited green tariffs will be made available to customers online.

The guidelines and accreditation scheme will require suppliers to show that their green tariffs are based on environmental activity that goes beyond their legal obligations to help reduce carbon emissions.