They were promoted as the eco-friendly way to generate both electricity and cash at the same time.

But now thousands of home-owners who bought solar panels have complained that they're not reaping the rewards they were promised.

The Financial Ombudsman Service has received 2,000 complaints and Barclays has put aside millions to compensate those who took on costly loans to pay for mis-sold panels.

Brian Thompson, from Gateshead, was persuaded to take out a £10,000 ten-year loan with Barclays to pay for solar panels, whose firm PV Solar UK promised would boost his pension

Martyn James, from complaints website Resolver, said: 'The mis-selling of solar panels has been going on for years.

'No one fully knows the scale of the problems but it is definitely one of the top ten scandals of our time.

'The people who bought solar panels are not greedy – they were genuinely trying to do a good thing by being self-sufficient.'

When Brian Thompson, from Gateshead, was contacted by a salesman from supplier PV Solar UK, which went bust in 2017, he told him he did not want to take a loan on as he was preparing for retirement.

But he says the salesman persuaded him to take out a £10,000 loan with Barclays over ten years with promises that the panels would boost his pension.

But the payments he got from the power his panels sent to the National Grid were not enough to cover the cost of the loan over 20 years.

He told the BBC: 'I had to dip into my savings which I was putting away for retirement to pay the loan off. To me it was lies.'

Another solar panel owner Tony Walch, from Bolton, was convinced by MyPlanet, which shut down in 2016, to get solar panels which it said would save him £30,000 over 20 years.

After taking out a loan of £15,000 he discovered the panels did not generate the amount of electricity MyPlanet had promised – and also cost him more than £500 a year due to overheating issues.

One couple took out a 15-year loan with Shawbrook Bank in 2012 to pay for their £15,000 solar panel system sold to them by MyPlanet.

The Financial Ombudsman Service has received 2,000 complaints and Barclays has put aside millions to compensate those who took on costly loans to pay for mis-sold panels

According to a ruling on the Financial Ombudsman Service's website they were told by MyPlanet that the panels would be self-funded and the loan repayments would be more than offset by 'feed-in tariff income', which pays owners for their electricity.

But this did not happen, and the ombudsman ordered Shawbrook to recalculate the repayments so they would be covered by the savings and pay compensation.

The average solar panel system costs around £6,200, according to the Energy Saving Trust. The Feed-In Tariff scheme closed to applicants in March.

However, those who had panels before it ended will still get the payments.

Chris Hewett, chief executive of the Solar Trade Association, said: 'We are sorry to see that a number of households have been adversely impacted by rogue traders mis-selling finance packages, and urge Barclays to ensure that the matter of compensation for affected customers is dealt with swiftly.'

Barclays said a £38.5million fund had been set up to compensate customers across a number of different product areas, including solar panels. Shawbrook Bank was contacted for comment.