Thousands of people who bought solar panels have complained to a financial watchdog that they are not bringing them the returns they were promised.
Many people took out loans to pay for panels on the promise they would save thousands of pounds in electricity costs and make money generating power.
They say they have not had the expected savings, and the Financial Services Ombudsman has had 2,000 complaints.
Barclays Bank has put aside £38m to deal with potential claims.
Brian Thompson from Rowlands Gill, Gateshead, told BBC Inside Out he was contacted by a salesman for PV Solar UK but told him he did not want to take a loan on as he was preparing for retirement.
He said he was told the move would provide money towards his pension, which persuaded him, and he took out a loan with Barclays of more than £10,000 over 10 years.
Mr Thompson said the payments he was getting back from the power his solar panels sent to the National Grid did not correspond with what he was told.
"I had to dip into my savings which I was putting away for retirement to pay the loan off. To me it was lies," he said.
An independent survey of Mr Thompson's system showed even after 20 years the income from the panels would not cover the cost of the loan.
Barclays offered him some compensation but Mr Thompson said it was not enough.
PV Solar UK went into liquidation in 2017.
Robert Skillen, who was the director of the firm when Mr Thompson bought his system, said Mr Thompson's panels would make him money.
Mr Skillen is now in business claiming to help people who have been missold solar panels. He did not want to be interviewed.
Tony Walch, from Bolton, was told he would be better off by £30,000 over 20 years when he bought solar panels from MyPlanet.
He said: "They were very, very persuasive. Everything they said was plausible. It was a no-brainer."
He took out a loan of £15,000 but he said the panels did not generate the amount of electricity he was promised. They also overheated, damaging the equipment, and he believed they had cost him more than £500 a year.
MyPlanet went into liquidation in 2016.
Former director Mark Bonifacio said all calculations had been made using strict methodology, and the performance of the systems was impossible to predict because of different factors affecting performance.
He said MyPlanet installed more than 15,000 systems, and customers would be getting free electricity.
Debbie Enever, from the Financial Ombudsman Service, said: "We have got about 2,000 complaints about solar panels at the moment and more coming through every week."
Loans for solar panels were taken out through Barclays Bank, which said: "We always seek to ensure customers are satisfied with our financial products. Where customers have cause to complain we will review each case individually."
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You can see more on this story on Inside Out North East & Cumbria and Inside Out North West on Monday 9 September at 19:30 BST.
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