"It just means that every time you turn on your lights [Chief Minister] Andrew Barr is going to be dipping into your pocket. Its going to cost Canberrans about $300 a year extra on their power bills, on top of the highest rates in the country, parking fees are going through the roof," Mr Hanson said. "The cost of living is becoming a real problem for many Canberrans."

Accusing the government of "trying to outmanoeuvre everyone in Australia", Mr Hanson said he would announce strong renewable and carbon reduction targets under a Liberal government, but with a balance between good targets and affordability.

Environment Minister Simon Corbell announced on Friday that the government would fund all of Canberra's energy needs from renewables by 2020. The move would add an extra $290 a year to the average household electricity bill of about $1500 a year, he said.

His announcement, which brought forward the 100 per cent target by five years, was widely welcomed by environment groups.

The Greens' Shane Rattenbury said the move was evidence of the influence his party had in the Assembly, holding the balance of power since 2008.

"It's times like this that I am reminded of the important role the Greens play in the ACT Assembly, as there would not have been the political will to proceed without the Greens," he said.

But there was still much to do to achieve the target of carbon neutrality by 2050, he said.

The Australia Institute released polling yesterday which shows overwhelming support for state-based renewable energy targets across the political spectrum, among Liberal as well as labor voters.

Executive director of the Canberra-based thinktank Ben Oquist said the ACT was showing national leadership and Mr Corbell's announcement put pressure on state and territory politicians around the country to better support renewables.

With uncertainty at the national level, the ACT's program had been responsible for most of the national spending on renewable energy.

The scarce resource was political will, but the ACT government was just getting on with it, he said.

No other state renewables target approaches the ACT's, with South Australia aiming for 50 per cent renewables by 2025, Queensland for 50 per cent by 2030, and Victoria to 20 per cent by 2020. NSW has no target.

ACT Conservation Council executive director Clare Henderson said the ACT should now commit to zero greenhouse gas emissions by 2040. The current target was a 40 per cent reduction on 1990 levels by 2020 and zero emissions by 2060, she said.

The director of the Australian National University's Energy Change Institute Professor Ken Baldwin said the ACT remained "the only game in town" and companies were rushing to be involved.

"The ACT Government ... is cashing in on the current low renewable energy prices, and will have first-mover advantage over other states by securing the cheapest electricity," he said.

The Australia Institute's March poll suggested that support for state renewable energy targets remains very high and is perhaps strengthening.

Nationally, more than three-quarters of Australians, 76 per cent, support or strongly support state-based renewables targets.

Support is almost as strong among Coalition voters as Labor voters, with 80 per cent of Labor voters and 74 per cent of Coalition supporting or strongly supporting state-based renewable energy targets.

Support in March was up on a November poll, which showed 72 per cent support across the country for renewables, although the margin of error for the Mach poll was 3 per cent.

In November 2015 when the first poll was done, the ACT government's target of 100 per cent renewable energy by 2025 (now brought forward five years) was supported by 78 per cent of Canberrans.

The bulk of the ACT's move to renewables is through buying energy from wind and solar farms, almost entirely interstate. The ACT is paying the companies for the electricity they feed into the national grid.