Consumers are being warned about signing up to expensive solar power systems after a surge in complaints about shonky solar companies and unscrupulous sales methods.

In December last year Peter Georgopolous signed up for a $13,800 solar system on the roof of his Greenvale home after a sales representative from Ires Asia Pacific promised he would never pay for electricity again.

Seven months on it is still not working.

"I don't even know how they work, if they work, because I got an electricity bill for $340 but they promised me I would get a bill for $32," he said.

Mr Georgopolous said that was not the only broken promise.

"He promised me it was all made in Germany and that it would be a German unit but when they came to install them and I saw the boxes the solar panels came out of, I could see it all said 'made in China'.

"They installed them and then I tried to ring the company [Ires] and after a few calls, five or ten calls, I eventually got through to one of the supervisors.

"I explained what happened. He apologised and said 'everything is made in China these days, but they're German quality'.

"It's like buying a Mercedes Benz and all of a sudden you get a Holden or Ford delivered.

"I looked it up on the internet and I made a few enquiries and the system is not worth more than five, six or $7,000 maximum. They charged me $13,800," he said.

Solar salesman promised 'impossible system'

Wendy Jones lives on a farm at Katunga in Victoria's north east.

She signed up to a $13,500 contract with Elite Solar and Electrical last year after a salesperson told her they could put panels on the roof of her house and on her shed and run them under the one system, meaning she would not have to pay for electricity again.

New energy businesses cannot be investigated by the energy ombudsman. ( ABC News )

"I had received previous quotes from other companies which were around $7,000 - $8,000 but went with Elite because they promised to put the house and the shed on the one system," she said.

"The salesman had the real gift of the gab but didn't know what he was talking about. We've since been told by other contractors that would never have been possible."

Ms Jones said the panels were still not working and her electricity bills were exactly what they were before the panels were installed.

She spent hours trying to chase the solar company but no one returned her calls. Elite Solar and Electrical has since gone into liquidation.

"The Finance Company [Certegy Ezi Pay] refunded our money and we still have the panels on the shed, but we don't know what we'll do about the warranty if anything goes wrong down the track," Ms Jones said.

'They sometimes struggle to ensure panels even work'

The Consumer Law Action Centre (CALC) has already received 50 complaints this year about solar power operators.

"We've had clients who have been targeted by door-to-door sales people or telemarketers being told they will never have to pay electricity again, only to find that they have been signed up to very expensive solar panels on finance arrangements," chief executive Gerard Brody said.

"And they sometimes struggle or have difficulty ensuring that those solar panels even work or are connected to the system."

All of the customers the ABC spoke to were signed up to payment plans by Certegy Ezi Pay.

"With these new finance offerings there isn't the same responsible lending obligations that you might see in the mainstream credit and lending markets, getting a loan from a bank for example, they have to ensure that you can afford the repayments," Mr Brody said.

Calls to overhaul solar industry regulation

In the case of Mr Georgopolous, Certegy refunded payments for the Ires system.

In response to questions from the ABC, Certegy said it "investigated and promptly agreed an outcome with the relevant consumer and we suspended IRES Solar's use of our service with the merchant".

Peter Georgopolous was sold a system made in China after being told it was German. ( ABC News )

"Some matters relating to IRES Solar remain under investigation and they cannot use our service."

But many in the business still do. Certegy Ezi Pay has 435 solar retailers on their books.

In the last 12 months, 15 have gone into administration and the finance company has terminated seven more for failing to meet Certegy's compliance requirements.

"Overall we have very few complaints regarding solar, with typically 96.5 per cent of customers paying their payment plans on time," the company said.

The ABC left a number of messages for Ires Asia Pacific but it did not return the calls.

The CALC has called for an overhaul of regulatory framework to better protect consumers.

"The risks are that with this quickly-changing marketplace, that poor business practices and selling practices can become imbedded quite quickly and many people can get ripped off in the desire to save on their electricity bills and generate their electricity more sustainably," Mr Brody said.

Ombudsman cannot investigate new energy businesses

But it is not always easy to get help if consumers have problems with a solar company.

Each state has an energy and water ombudsman, but their scope does not include new energy businesses like solar so consumers must take the matter to court.

"People need to have a place to go to resolve disputes quite easily and simply. The energy and water ombudsman service at the moment can't consider these sort of disputes with solar providers," Mr Brody said.

"We're seeing more solar providers enter the marketplace and we'll soon see battery storage come into the marketplace.

"The risk is that pretty poor practices could get into the sales and marketing of those products and people could find themselves without an easy place to resolve those disputes."