WHEN Neil Rayner put solar panels on his roof, he did so under two assumptions: it would help clean up the planet and that his electricity bills would become noticeably cheaper.

He was wrong on the second count.

Mr Rayner's electricity costs are increasing - the result of being forced to pay a much higher rate for power drawn from the national grid than people without household solar systems.

''It is a rip-off and the problem is we are not told that this would happen when we put solar on,'' he said.

Mr Rayner is not alone. The average non-solar home is charged between 17¢ and 19¢ per kilowatt hour of electricity used due to a Victorian government moratorium on price increases while a new ''smart'' metering system is rolled out.

But in what is described as an oversight, the moratorium does not apply to households that sign a contract to receive a premium rate for excess power generated on their roof and fed into the grid.

Instead, energy companies are charging people with photovoltaic solar panels up to double the standard rate during peak hours.

In Mr Rayner's case, AGL charges him 32¢ per kilowatt hour during the evening - the time he is most likely to need the power grid to run his home in McKinnon.

''If I had known, I would not have put panels on my roof - it's not worth it,'' he told The Age.

''I reckon I could just about set up a business explaining to people what they need to look out for if they are thinking of putting solar on, because it's become a very complicated exercise.''

Chris Shattock, of Beaumaris, estimates that since installing solar panels at his home his electricity charges have been 40 per cent higher than if he had been charged the lower rate reserved for non-solar homes.

''By having panels I am at a big disadvantage, even though I am being paid to feed some electricity back into the grid,'' he said.

More than 22,000 rooftop solar systems have been installed in Victoria.

Environment Victoria campaigns director Mark Wakeham said people with solar panels were being treated poorly. He called on the government to intervene.

''People with solar are being forced on to higher tariffs during peak hours despite the fact they are doing more than other customers to alleviate peak electricity demand,'' he said.

''It is a problem that needs to be fixed quickly so we are not penalising those who are doing most to clean up our energy supply and reduce peak demand.''

Energy Minister Peter Batchelor's spokeswoman, Roxanne Punton, said it was ''extremely disappointing'' that energy companies were not making some solar customers aware of changes to electricity tariffs.

She said the government did not want households penalised after installing solar panels.

''That is why we are currently working with solar industry advocates and energy distributors and retailers to resolve this issue quickly,'' she said.

People who believe they have been misled about changes to electricity tariffs are advised to contact the Victorian Energy and Water Ombudsman.