Consumers face years of rising gas and electricity bills as the UK heads towards an energy crunch, according to the chief executive of one of Britain's biggest power companies.

Paul Golby, of E.ON UK, said it was time for the industry and Government to come clean about the extent of the UK's energy needs - and what it will mean for domestic prices.

E.ON believes that building the necessary new generating capacity - from renewables, nuclear and coal and gas - could cost between £50bn and £100bn. All this must be paid for, Mr Golby said.

In a frank warning yesterday, Mr Golby criticised the quality of debate about the country's energy future, saying that it was dominated by single issue politics. He called on the Government to take a lead in improving understanding of just how serious was the challenge to "avoid the lights going out".

He criticised in particular the notion that moving towards renewables was cheaper. "We must dispel the myth that renewables are cheap. Because we have all been silent on this, people think it won't cost anything.

More on energy

"I'm not saying that moving to renewables is not the right thing to do. But we need to be honest with our customers. Moving to a low carbon economy is going to cause some economic pain in the short term," Mr Golby said.

As Britain becomes more dependent upon imported gas, and as ageing nuclear generating capacity is taken off-line, consumers will have to pay more for their energy.

The development of renewable power - especially wind - and a new generation of nuclear power stations will eventually ease the problem, but not until well into the next decade.

"If you look at how wholesale [gas] prices have gone, they have accelerated significantly ahead of retail prices. Looking forward into the future, I can't see that the fundamentals are going to change to bring those prices back down," Mr Golby said.

"The reality of the problems facing us is undeniable - an unparalleled transformation of our energy generation infrastructure at a time when prices are high and rising."

Parts of England suffered blackouts last week after unscheduled power plant production halts. That's an indication of the "ageing infrastructure we have in this country," Mr Golby warned. The cost of creating new network connections, as well as operating the new infrastructure in meeting these targets, will cost tens of billions of pounds.

The UK currently has 76 gigawatts of generating capacity, with about 25gw of this coming to the end of its life as ageing power station are decommissioned. But Mr Golby said that by 2020 the UK will need more than 120gw of capacity.

The European Union's carbon emissions reduction targets mean the UK may have to build about 50gw of renewable capacity.

E.ON has a working assumption that Britain will have to spend £50bn-£100bn on new generation and infrastructure if it is to secure the energy it needs. The company is currently reviewing the cost and hopes to publish a more detailed breakdown of its estimates in a few weeks.

The cost of large-scale renewable projects are soaring, with a shortage of wind turbines and engineers pushing up costs.

Centrica, owner of British Gas, warned in April that the spiralling cost of a huge offshore wind farm project could make it uneconomic. And construction of the proposed London Array wind farm, in which E.ON has a 33pc interest, has been held up by Royal Dutch Shell's decision to withdraw from the project because of rising costs.

Mr Golby, who was launching E.ON's energy manifesto, said his call for an "honest debate" about Britain's energy future must include a recognition that new coal-fired generation "will play a significant role in restraining prices".

He said: "Without coal, bridging the energy gap will mean allowing gas to dominate our energy mix and a second "dash for gas" is something we need to avoid." But new power stations must include carbon capture and storage technology.

E.ON UK would play a role in the building of a new generation of nuclear power stations, he said, adding that the company had three options: to buy power stations from British Energy, purchase sites from the Nuclear Decommisioning Agency or build on new greenfield or brownfield land.