Electricity or gas heating

Without a carbon tax on the fuels it’s not apparent the energy conversion losses are fully reflected in the cost to the consumer.

The linked article, offers a short comment on the difference in raw energy consumption with a guesstimate of the CO2 emissions. These relate to the carbon emissions from combustion - generation using FF vs in home combustion. The blogger does short hand the comparison, but notes the outcome for users of electricity in Tasmania is favoured by it’s close to 100% use of renewables for generation. It varies depending on the network your power comes from.

Even an air conditioner entirely powered by coal can result in lower emissions than those that directly result from burning gas for heat, as the following three steps show:

The tariffs/prices the article uses from 12 months may not align with other consumer experiences? The prices from the latest standing offer determinations in each supply area would offer the most reliable base comparison.

It’s a more complex discussion, for homes with Solar PV or ToU tariffs. Also of note NG plans can also include variable pricing, typically the more you use the less the unit cost. At that level of complexity it is more like comparing the costs of running different names and models of cars, all of which have different levels of utility, fuel consumption, maintenance, and importantly initial cost. The price of diesel and petrol is not assured nor reliably forecast. The same holds for electricity and reticulated gas.

The blog points in single direction. The indicative figures are based on simple assumptions. Individual consumers will find their relative financial benefits differ.

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I don’t see that as important for making decisions about the cost of electricity or gas. Similarly, using a carbon price will make a difference to total cost but I don’t see the value in teasing out that component. It may matter if you want to consider the environmental costs but the above graphs don’t do that.

The most important principle is to make sure you include all the relevant aspects so you get a proper comparison. Which the above graphs and other references often fudge by leaving out capital costs of the various options. The cost of heating a room 20 X 20 ft with 10 ft ceilings is more than the cost of gas or power at the meter.


:slightly_smiling_face: I can only agree.
The energy markets are in a state of instability, IE market pricing and transition. Also a factor that may encourage change or give cause for hesitancy.

Getting back to the OP’s topic: an authoritative comparison of costs of heating a home using ducted gas verses using reverse cycle aircon (assume split system/s).

Cameron Chisholm, Energy Program Associate, Grattan Institute puts the cost of gas heating at twice that of electric heat pumps in


That was seven years ago, both the gas and electricity markets have changed a lot since then so I don’t know how authoritative it is now.

I agree that stated as running cost only the conclusion is probably still broadly correct. However, if it was me I would be looking at details of prices in my own location and thinking about the future, whether the prices of gas and electricity are going up, down or sideways over the next 20 years.


Depending on your electricity plan, you may find that you have off peak electricity. Typically on weekends and from 10pm to 7am. Try heating house with Air con on weekends. Air con units loose efficiency when its really cold and the outdoor fan unit may freeze up. Consider heating with gas when really cold outside ( first thing in the morning) and then Air con once outdoor temp lets say reaches 7-10C.
The big win is to go off gas all together and save the daily delivery charge. Fit solar and go all electric.
My previous house has ducted gas heating and two Air con units, I tried Air con only for a few weeks and it worked out cheaper. Just hard to quantify how much with different bill cycles and length and it was four years ago. From what I remember it cut the gas by $150 and spend $40 more electric.
As a side note, check the Air con filter on the indoor unit and clean as required.

Can someone please tell me where one finds an HVA I need one because I want to get rid of my underfloor gas heating - too expensive and too environmentally unfriendly!

For underfloor ‘gas’ heating assume you have an external gas boiler with underfloor piping and a pump to supply heated water to warm the floor area. (Aka hydronic heating)

Assume your enquiry is looking for an HVAC hydronic heating specialist. The alternative to a gas boiler is an electric heat pump which can utilise your existing underfloor heating. All the benefits of underfloor heating utilising a highly efficient heat pump.

Search your yellow pages for hydronic heating specialists and look for those offering heat pump alternatives. I’ve only had prior dealings with Hunt Heating in Melbourne. Not a recommendation, just one example of the type of business a search should identify.

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We did have someone come and look to quote, but he said there just wasn’t enough space under the house to replace the gas “tunnels”(don’t know what they are called!) He said he would like the work, but it was just not possible. So it looks like we are a bit stuck.

What you are describing is a ducted system with gas heating. There may be a concern with the condition of the old ducts. Assuming the existing duct sizing and heating has been adequate, it’s unexplained why there would be a concern with the space available.

It can be beneficial to seek out more than one business and obtain multiple opinions and solutions. Knowing the general locality of your home may assist others to offer suggestions.

Several readily found on line offer general advice, that may clarify key concerns. It is possible to reuse existing ductwork conditionally, with a heat pump replacement for the gas heater. A phone call with a list of prepared questions is a good follow up to an internet search for HVAC specialists promoting ducted and reverses cycle systems.

Gas Heating to Ducted Air Conditioning Replacement Sydney | Energy Efficiency

Benefits of Replacing Gas Heater with a Heat Pump | Ideal Air Melbourne

Could be working space? One end of my house is pretty tight under floor and a pre teen sized person might be able to manipulate tools in the first meter or two from the wall. An adult? Maybe or not. Fortunately I do not have anything that cannot be done there by sliding bits in and out.

I know a family with a low pitched shingle roof circa 1975 US ranch style. Work in the ceiling cavity requires a fit person of extremely trim proportions having no claustrophobic tendencies. They had a quote with a line item of $3,000 above the work to arrange a capable and willing person to crawl in the space and potential liability if it went bad. Removing the roof or portion thereof, not an option/practical.

Overall total east coast demand for gas in 2027 is expected to be approximately 493 petajoules under the scenario Aemo treats as most likely.
Australia is facing gas shortages. We shouldn’t be here, but there is a way out | Tristan Edis | The Guardian

Of that total approx 30% (one third) will be consumed by Australian households. In response to suggestions there will be a shortfall in supply The Guardian points to several initiatives to reduce consumption.

The better option is that we curtail the inefficient use of gas to heat our homes and water. According to Australian government figures, heating our homes consumes 90 petajoules of gas per annum, while heating water consumes another 50 petajoules. Victorian households account for more than two-thirds of this consumption.

Victoria in particular has been providing subsidies to convert including to efficient HWS, heat pumps.
Edit: note there are like all government offers conditions as indicated in the following 2 posts.
For those considering converting to all electric, the upcoming Federal Budget is expected to include additional financial support for consumers looking to transition and reduce gas consumption. It will be worth a broader look at the relative costs plus the costs to convert than the current topic has covered,(when further details become available).

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Some caveats in the program.

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A bit OT since the topic started as a home heating question but for anyone interested in the Vic program.

If you peruse the linked lists of ‘approved’ products you might be surprised that a number of higher efficiency natural gas hot water services qualify for the program, or put another way if you already have one of those in the approved list you cannot get a replacement heat pump through the program.