Household energy bills are likely to rise £100 a year more than the government projects, says the energy firm RWE Npower.
It says official predictions of future energy savings are over-optimistic and warns the average bill will rise £240 a year by 2020.
The firm says it supports government plans to renew power networks and build more renewables such as wind and solar.
But it says there must be more honesty about the costs of this investment.
It comes as a new poll by Cardiff University suggests that the public is willing to pay extra for clean and reliable energy.
What’s interesting is that, despite what you might see in parts of the media, it’s clear that very broadly the public want a long-term commitment to clean energy”End Quote
Professor Nick Pidgeon
Both reports acknowledge, though, that the public does not trust energy firms or government – and both say trust must be restored if energy policy is to succeed.
In Npower’s case, the trust exercise starts with a publication setting out exactly how bills are likely to rise, in order to renew the creaking energy supply system and install clean energy supplies.
The firm says it believes the government has underestimated the effect of this investment on b