Greens Leader Bob Brown has played down a report that says households will be forced to pay up to 30 per cent more for electricity by mid-2013.

The Government's chief energy advisory group was asked by the Council of Australian Governments (COAG) to forecast electricity price trends over the next three years.

The Australian Energy Market Commission has warned higher infrastructure costs will cause household electricity costs to rise across the country.

The report found the Federal Government's plan to have 20 per cent of electricity from renewable sources by 2020 will contribute 11 per cent to the price rise.

The Productivity Commission warned earlier this week that the renewable energy incentives being demanded by the Greens are pushing up energy costs for comparatively little environmental gain.

But Greens Leader Bob Brown says renewable energy would look cheaper by comparison if coal-fired power was not heavily subsidised.

"Renewable energy and energy efficiency are an investment for the future," he said.

"It's just that we've got our market configured wrong because coal-fired power is hugely subsidised. Take those subsidies away and renewable energy looks better and better."

Most of the price hike is due to greater energy needs and the increasing cost to maintain power grids. Higher fuel prices and uncertainty over a carbon price will also drive up wholesale electricity costs.

The report was released after a meeting of energy and resources ministers in Perth, who vowed to hold special meetings to "consider energy security implications arising from the introduction of a carbon price".

But the commission warns the report was completed in November, and some of the data may now be out of date.