The UK's National Consumer Council and consumer watchdog Energywatch have issued a challenge to Britain's household energy suppliers to be more honest and upfront about their 'green' tariffs - and to spell out clearly what the environmental benefits really are.

The call comes as National Consumer Council (NCC) research shows that, while many consumers say they’re happy to pay a premium for green energy, most green tariffs don’t live up to the environmental benefits claimed.

For instance, no supplier, whether ‘green’ or otherwise, makes it clear that every British household is already supporting renewable electricity to the tune of GBP7 a year through their normal electricity bills. Also, the complex rules that encourage all energy suppliers to source renewably can mean the electricity’s ‘greenness’ is oversold. Even choosing a green tariff that offers to plant a tree would not contribute anywhere near enough to offset a household’s carbon emissions.

Lord Larry Whitty, the NCC’s chairman, said: With consumers increasingly trying to do their bit for the environment, switching to a green tariff should be a simple way for them to make a difference. But our investigation shows that it’s too easy for consumers to be confused and misled. They may think they are helping save the planet, but it’s not clear that they are.

That’s why we’re calling for a shake-up in how companies market and sell their green tariffs, and for them to offer bigger environmental benefits. Even the better tariffs would only cut the CO2 emissions of a typical household by around 6%.

The NCC and Energywatch will be pressing energy suppliers to sign up to minimum standards for green claims and have their tariffs and CO2 savings independently audited.