"According to industry standards they're meant to be cleaned every three months. They're just like a glass window, dirt and grime build up," Brian Harvey said.

Mr Harvey has had solar panels for the past three years, but said it was only when he saw a pamphlet for someone offering to clean his solar panels that he realised they needed cleaning.

"It's coming up to three years with mine and they've never been done. There'd be a lot of people in Dubbo in the same boat," he said.

Dubbo has the highest number of solar powered homes in Australia.

More than 2,100 solar PV systems are in operation under the 2830 postcode, the equivalent of 28 per cent of the city's houses.

Mr Harvey said when his solar panels were first installed, they were producing 10 kilowatts of energy, but before he had cleaned them, they had reduced to around 8.5kW.

"There is a case to say these things need maintenance like anything else semi-mechanical," Mr Harvey said.

"People need to take the steps to clean them, not just put a hose on them.

"They need to get the squeegee out."

He said the dirt and grime on the panels was the equivalent of people wearing sunscreen however, he said he believes it is unnecessary to clean them every three months.

Mr Harvey said anyone cleaning their solar panels should maintain safety and be careful while climbing on their roof.