William Holdsworth's solar panels were on his roof for five years before he realised they were never connected to the grid.
It was 2011 and then aged 75, Mr Holdsworth was looking for a way to reduce his household expenses.
More National News Videos
Maximising your solar panels
New energy data readers are helping households around Australia combat high electricity bills by ensuring solar power is prioritised in the home is not sent to the grid.
He spent about $3000 on the solar system, but he's yet to see the savings on his electricity bill.
Today, the panels lie dormant on his roof; now redundant due to changes in standards since 2011.
"I was under the impression whatever I saved was built into the main bill. So I just left it at that," said Mr Holdsworth, now 81.
Six months ago, his son took a closer look at the most recent electricity bills for his home on the outskirts of Melbourne.
He found no savings had been realised in five years, because a crucial Certificate of Electrical Safety, required to finalise the connection, was never received by Mr Holdsworth, the retailer or the distributor.
"Being a pensioner ... it hurts, because $3000 is a lot of money to me," Mr Holdsworth said.
Emails from the installation company Solargain to Mr Holdsworth's retailer in March said the relevant paperwork was sent to all parties in 2011, but now it was "unfortunately unable to provide any documents" to complete the installation.
In the past week, Solargain have agreed "in good faith" to bring the system up to current standards, "but only under the explicit understanding that [they] are not in any way encumbered to do so".
A Solargain spokeswoman disputed the claim that the system had never been connected to the grid, saying the "installation was commissioned in 2011 and revisited for warranty works in 2012" when it was proved to be connected.
"Solargain is an ISO accredited, Quality Assured company … a Clean Energy Council Member, [using] Clean Energy Council accredited installers. The ISO accreditation holds itself to a higher standard than this membership requires. We regard our processes and methodologies to be best practices."
Advisers from the Consumer Action Law Centre, who have assisted Mr Holdsworth with his case since February, said the fact the requisite paperwork was never received showed the system connection was never completed. As such, Mr Holdsworth has never received a feed-in-tariff.
The centre is calling for a mandatory code to be implemented to monitor the solar industry.
"There's no compulsory requirement for these companies to be part of an ombudsman scheme," said policy officer Jake Tilley.
"This is because regulation isn't keeping up with new products and services ... people are buying what they think is energy service, but the reality is it's not covered by the protections available in the traditional market."
He said the company should have ensured the order was complete, as it was "quite clear Mr Holdsworth was elderly".
While there are 550 business and 4500 installers listed within the Clean Energy Council member base, just 47 retailers have voluntarily signed up to the council's Solar Retailer Code of Conduct.
Centre solicitor Jesse Marshall said despite the "good faith" gesture in the past week, the case shows "why consumers need access to free, effective independent dispute resolution".
Mr Holdsworth is one of 25 consumers with solar-related cases to contact the centre in the past three months.
In NSW, Fair Trading has received almost 1000 complaints about solar panels and solar-related products since January last year.
Most complaints relate to defective or unsatisfactory goods or work, closely followed by non-supply of goods and services.
Mr Lilley said the growth of the solar retailing sector had resulted in an increase in enquiries for assistance.
"We've heard multiple stories of door-to-door sellers making ridiculous claims, often dishonestly claiming that a household will never have to pay for energy again if they get solar panels."
Clean Energy Council director of SmartEnergy Darren Gladman said the body had reinstated calls for a mandatory code in the past year.
"[It] would raise the standard across industry and provide a higher level of protection for customers," he said.