Households who want to go green might find that installing solar panels on their roof is not the smartest way to go about it.
Switching to Greenpower or buying a solar hot water heater could give consumers more bang for their buck, according to consumer group Choice.
Choice has released two reports which found the high cost of installing solar panels – up to $15,000 for a relatively small one kilowatt system - means they take at least 15 years to pay themselves off.
By contrast, a solar hot water heater, which sits on the house's roof and uses the sun's rays to heat water, costs considerably less.
Prices started at $4,000 exclusive of government rebates.
"More people should really get into solar hot water," Choice spokesman Christopher Zinn told AAP.
But consumers should do their homework on solar hot water heaters as some deals were too good to be true, he warned.
"Beware of some of the advertisements which say hot water free from the sun ... it's not," Mr Zinn said.
Another option was Greenpower, or buying renewable energy from an electricity supplier, which cost $4-$7 extra a week.
"It can involve people in using a renewable power source, it's just that you don't have it quite on the top of your roof," Mr Zinn said.
He said while installing solar panels might be a relatively expensive way to help the environment, it was still a worthwhile option for some.
A long pay-back period was not necessarily an insurmountable hurdle - having children also had a long pay-back period, Mr Zinn noted.
"The pay-back period for (kids) is much longer than photovoltaics but people continue to do it," he said.
Mr Zinn said there was a degree of confusion around the technologies, costs and rebates for environmentally-friendly energy options and urged consumers to inform themselves.
