A new study has found the future prices of wind, thermal and solar power will only keep falling as more alternative power sources are switched into the energy grid.

Researchers say it proves the widespread adoption of renewable energy sources makes good economic sense.

The study was commissioned by the Government's chief climate change adviser, Ross Garnaut, and conducted by the University of Melbourne's Energy Research Institute.

"We found that the current cost of technology such as solar and wind today are already cheaper than the data that is currently used by Australian Government and industry planning," said one of the study's lead researchers Patrick Hearps.

"Not only that, the cost of solar and wind are expected to drop quite significantly over the next decade."

Mr Hearps says the study proves the economics of renewable energies are viable.

"It's expected that, especially in the case of solar technologies, that they'll become very close to competitive with fossil fuels over the next five to 10 years," he said.

"What this means is that we should be planning for a future with much larger penetrations of renewable energy and focusing on how we get that built and how we can integrate into the system as fast as possible."

Debate about renewable energies often centres on the up-front costs of the infrastructure.

But Mr Hearps says the significant costs are worth the investment in the long-run.

"The costs from the Zero Carbon Australia 2020 Stationary Energy Plan were an upfront capital of $370 billion," he said.

"Now if you take into account what that does to electricity prices, that would see a price rise based on our models of about 6.5 cents per kilowatt hour which equates to about roughly $8 per household per week.

"Now you have got to keep in mind that the cost for electricity is going to rise anyway, even if we continue with our existing fossil fuel infrastructure because coal and gas is getting more expensive and we are still not paying for the emissions that are caused by that."

The findings of the study are sure to be welcomed by groups advocating renewable energies.

Matthew Wright, the executive director of think tank Beyond Zero Emissions, says the savings can be significant.

"If you take the data from the International Energy Agency or the data from the US Energy Information Administration or the US Doe, it shows that for instance rooftop solar ... [it] can be down as low as 10 cents a kilowatt hour," he said.

"[That] is one-third of what people will be paying at the meter in a decade, so obviously everybody will be putting that up and it won't need subsidies."