Gas worse than electricity on household CO2 emissions, report finds

A switch from gas to electricity for heating and cooking in Australian households might not only be cheaper, but in most cases would be better for the environment, a new report has found.

The report, released on Tuesday by the Alternative Technology Association (ATA), found that in most cases and for most households across Australia, switching from gas to efficient electric appliances for space heating, water heating and cooking produced less greenhouse gas emissions.L_z324497

Titled “Are We Cooking the Planet with Gas?”, the report analyses the emissions impacts of the scenarios outlined in the ATA’s 2014 analysis on the economics of gas versus efficient electric appliances, Are We Still Cooking with Gas?

The analysis covered 156 household scenarios across 26 locations in Australia and found that for the majority of households, completely moving away from gas to efficient electric was not only cheaper, but less greenhouse intensive.

“In the few cases where we found there were emissions increases, they were very small and could be offset by the purchase of 100% GreenPower electricity at a maximum cost of about $10 a year per home,” said ATA policy and research manager Damien Moyse.

The report’s key observations included the finding that carbon dioxide emissions were lower when switching all three traditionally gas-fuelled household appliances (space heaters, water heaters and ovens/stovetops) to efficient electric appliances.

This was consistent across household scenarios and all locations apart from Mildura, Victoria, where there was a small increase as a result of the switch.

The report also found that on a single appliance replacement basis, space heating was consistently found to be less emissions intensive when delivered by efficient electric appliances as opposed to gas.

The emissions impact of water heating varied by location, according to the report, with all Victorian and some NSW/ACT locations experiencing a minor increase in emissions with a switch to efficient electric, while South Australia, Queensland and other parts of NSW experienced a reduction.

Comments

4 responses to “Gas worse than electricity on household CO2 emissions, report finds”

  1. Alan Baird Avatar
    Alan Baird

    Makes perfect sense. If home heating safely, gas has to flued to carry away fumes as well as quite a bit of the heat. Electricity doesn’t. Heating water, same thing, gas goes “around” but not “inside” the water as in an electric kettle. Making either competitor by alternative means is easier for electricity too!

  2. Patrick Irwin Avatar
    Patrick Irwin

    No mention here of the Carbon from generation.

  3. Brad Sherman Avatar
    Brad Sherman

    Patrick is right, the report does not really address CO2 emissions. It falls into the trap of the magic pudding CoP logic. CoP is all about shifting heat – not creating it as the authors incorrectly state. RC performance degrades as outdoor temperatures get colder because there is less heat available to shift to the other side of the wall.

    When transmission losses from generator to home (7-15% of generation) plus the efficiency of thermal generation of electricity (25-40%?) are considered I doubt if there is a large CO2 advantage to electric over gas where heat is the end product and a total life cycle approach is employed.

    Of course, if you use 100% renewable electricity then you can use as much electricity as you like and have no impact on the climate. In this case, electricity obviously emits less CO2 than gas.

    1. Tim Forcey Avatar
      Tim Forcey

      As I understand it, standard Coefficient of Performance (CoP) tests for heat pumps are done at 7 C temp “outside” the building (i.e. ambient temp). Yes, when the outside temp is less than 7 C, the CoP will be less than stated. When the outside temp is greater than 7 C, CoP will be better than stated.

      7 C is taken to be an average sort of operational outside temp.

      To do more sophisticated analysis, one would need detailed weather data (to determine “outside” temperatures) and the performance curve for the heat pump or heat pumps in question.

      For more info, see: https://theconversation.com/hot-summer-nights-and-cold-winter-evenings-how-to-be-comfortable-and-save-money-all-year-long-51046

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