According to the Australian Energy Market Commission's latest figures, 70 per cent of ACT electricity customers and 68 per cent of the territory's natural gas customers are still on default offers, commonly known as standing offers.

As of Tuesday, ACT residents on the ActewAGL standing offer would have an annual energy bill of $3834 if they used seven megawatt hours of electricity and 39 gigajoules of gas per year.

An analysis of the ACT's residential energy market offers shows using the same amount of energy on Origin Energy's 25 per cent maximiser market offer would bring the bill down to $2818 – a saving of $1016.

Energy Australia's no frills market offer for electricity and its 11 per cent anytime saver market offer for gas would slash the yearly bill by $705.

ActewAGL's 20 per cent dual fuel market offer worked out to be $627 cheaper than its standing offer.

Standing offers used by energy suppliers have been criticised for years because loyal customers miss out on discounts and are punished for not shifting to different suppliers.

Consumer Affairs and Climate Change Minister Shane Rattenbury encouraged all Canberrans to get in touch with local retailers and actively look for ways to save.

"There is competition in the ACT and there are savings to be had," he said.

"This includes changing between standing and market offers with your current provider.

“The difference between offers is increasing which makes it more important than ever that consumers shop around for a better energy deal."

Origin Energy general manager of retail sales and marketing Duncan Permezel said the number of ACT customers on standing offers was striking.

"Around 70 per cent of the market isn't even engaged," Mr Permezel said.

"The ability to save 25 per cent with just one phone call or by going online is a lot easier than trying to change your habits around electricity usage.

"Even if it's not with Origin – even if you go with one of our competitors – it's that simplicity of change. Staying on a standing rate is very expensive."

O'Connor resident Simon Wilson, who recently switched from a standing offer to a market offer, said he was thrilled with the "significant savings" of about 12 per cent on his bills.

"It's just made a massive difference with the bills," he said.

According to the federal government's Your Home guide to environmentally sustainable homes, 40 per cent of the average Australian household's energy bill is spent on heating and cooling.

To save money during the warmer months, the guide recommends setting the air-conditioning to 24 degrees Celsius or higher, because each degree under that uses about 10 per cent more energy. It also says using the air-conditioning only when the temperature is above 30 degrees Celsius could save you up to $340 a year.

During Canberra's freezing winters, it is best to set the heating between 18 and 20 degrees, because each degree above 20 uses about 10 per cent more energy.

Heating and cooling is by far the greatest use of residential energy in Australia. Hot water and appliances each account for 21 per cent of the average household's usage, with cooking, refrigeration and lighting each making up 6 per cent.

Both sides of federal politics have promised to take action on energy bills in the lead-up to this year's election.

In October, federal Energy Minister Angus Taylor outlined new measures to set a default offer price that would save millions of customers on standing offers up to $832 a year.

That followed Opposition leader Bill Shorten's announcement in August of plans for simpler bills with "capped" prices under a Labor government.

The federal government is currently running an advertising campaign encouraging all Australians to ask their energy company for a better deal. Tips on how to do this are available at poweringforward.energy.gov.au.

Correction: An earlier version of this article said residents on the ActewAGL standing offer would have an annual energy bill of $3384 if they used seven megawatt hours of electricity and 39 gigajoules of gas per year. This was a typographical error. It should have said an annual bill of $3834.