New research has suggested that energy customers across the UK have little knowledge on the concept of green tariffs.
The study by energywatch found that 46 per cent of people, which equates to around 11 million, have admitted to not knowing anything about the products.
It was also found that while seven per cent claimed to be on the deals, online one per cent actually are.
Jonathan Stearn, head of campaigns for energywatch, said consumers were being "left in the dark" by energy suppliers.
He said: "They do not know how much has been allocated from renewable sources, nuclear power or fossil fuels.
"We all should be given a fuel mix for the electricity we buy so we can start to understand the claims that suppliers make."
energywatch recently described new plans by the government to help those struggling with fuel poverty as "deeply disappointing".
The organisation's campaigns director, Adam Scorer, said the new measures have "a hollow ring to them".
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