The coalition has unveiled measures it says will knock £50 off the average energy bill, but some of that cost will be absorbed by taxpayers.
The Government has laid out its ideas on how to cut energy bills this winter - but the plan has been put together in haste.
With prices going up, millions of the big 6's customers certainly feel the firms are making too much cash. How much are they really making?
The Co-operative Energy firm has announced a price rise of 2.5% on average.
In an email to customers, the company said: "As winter sets in and some energy companies raise their prices by as much as 10%, we’ve got some good news for you to warm to.
"Co-operative Energy is raising its prices on 8 January…but only by 2.5% on average across all our customers."
Energy Secretary Edward Davey called E.ON's price rises announcement "disappointing news".
Bur Mr Davey stressed:
This rise is ... lower than it would have been as a result of Government action to reduce the impact of price rises on consumers.
As part of their announcement today, E.ON have confirmed they will pass on these savings to their customers.
This does not let energy companies off the hook.
Asked about the timing of E.ON's price rises announcement, which came amid media focus on the death of Nelson Mandela and the devastating storms across the UK, Downing Street said, "It is for them to explain their decisions."
E.ON has announced its customers' dual fuel energy bills will increase by an average of 3.7% from January 18.
The company said that means the average variable dual fuel bill will go up by £48, electricity only prices will increase by 3.7% or £20, and gas only bills will climb by 4.6% or £37.
Chief executive Tony Cocker said changes announced by the Government earlier this week reduced the overall level of the rise that was necessary to cover extra costs.
The energy firm said it was "working hard to limit the impact on its customers" by announcing a lower average percentage rise than any other major supplier.
Earlier this week, E.ON said it did not expect to have to raise prices in the next 18 months "as a result of social or environment obligations".
But E.ON also warned, "There remains a risk, however, that increases in network charges or wholesale energy costs for example could force a price increase".
The announcement followed the Government's shake-up of green levies on Monday.
Energy supplier E.ON will increase prices by an average of 3.7% from January 18.
The UK Independence Party has called the cut to onshore subsidies a "political stunt" to buy off voters opposed to turbines "despoiling the British countryside".
Energy spokesman Roger Helmer said the change "fails to address the real argument which is the nonsensical and frankly dangerous energy policy this Government is forcing upon UK taxpayers".
He said the taxpayer would still have to fund "this wasteful and downright ridiculous technology to be built out of sight".
An industry body representing the renewable energy sector has said that Government changes to subsidies are good news:
– Dr Nina Skorupska, Renewable Energy Association
Today is actually a good news day for renewable electricity and renewable heat.
The real reason that support for solar and onshore wind will go down is that they are leading the race for cost-competitiveness with fossil fuels. Government policy is working and bringing down costs.
The important thing is that decisions are evidence-based, not purely political, and we need to see the methodology to assess that.
Prime Minister David Cameron has told ITV News' Deputy Political Editor Chris Ship that the coalition's announced cut in energy bills was not in response to Labour's proposed energy price freeze.
Speaking in China, Mr Cameron said: "We have been discussing within the coalition the issue of energy bills for years now. It has taken me longer than I would have liked but I'm very glad we put in place at least some relief on the issue of energy bills."
Energy Secretary Ed Davey has said that the decision to reduce subsidies was driven by the falling costs of generating onshore and solar energy, and not political pressure.
He told ITV News: "Because of our investments in renewable energy, we are seeing the costs fall ... It means we can still develop onshore wind, still develop solar, but it means we can also bring on some of the technologies for the next decade like offshore wind".
Rural wind farms have been a source of coalition tension, with many senior Conservatives staunchly opposed to the turbines, which Liberal Democrats say are needed to meet environmental objectives.