How to be green – appliances versus air conditioning

gadgetsMy public confession of not being able to give up gadgets resulted in a comment about an article from the US about how the energy efficiency savings from air conditioning units is being wiped out by the increased energy consumption from appliances in our homes. Thanks Ed.

So is it true in Australia? Big data can help.

Please note this is not a post about the absolving of guilt of my gadget use, nothing can forgive that.

Electrical Consumption from Appliances

Well, as it happens, yes our electrical consumption from appliances has increased between 1990 and 2005 by approximately 26%, but the proportion of electrical use in a house that is used by appliances has stayed steady at 50-55%. So if the proportion of electricity use from appliances has stayed steady but appliance electricity use has increased must mean that the electricity consumption in the average house must have increased.

Electrical Consumption in an Average Australian House

Between 1990 and 2005 the electricity consumption in an average Australian house has increased by 17% with the greatest percentage increases coming from heating at 73% and cooling at 164%. So in percentage terms the electricity consumption from heating and cooling has increased way beyond electricity consumption from appliances. Electric water heating and electric cooking has reduced between 1990 and 2005 as many homes has switched from electric to gas water heating.

So in percentage terms I’m ok with my gadgets!

percentage change

The actual consumption in kWh over a year gives a slightly different picture.

annual elec

The increase in electrical consumption from appliances is approximately 900kWh per year versus 625kWh per year increase from heating and cooling, appliance electricity use is some 50% more than heating and cooling for an average Australian household.

So my gadgets aren’t so good after all.

But the hypothesis from the US article is that appliances have soaked up the efficiencies in air conditioing

In Australia this is definately not true. We haven’t seen any reduction in heating or cooling between 1990 and 2005, in fact the number of houses with air conditioning has increased dramatically – in 2000 only 35% of homes had cooling, in 2008 this was 66%!

So at the moment I can’t see any efficiency gains in cooling and heating to be soaked up by gadget use!

But yes, the use of appliances in homes outweighs the use of air conditioning by a factor of 10.

Maybe we should leave house energy ratings where there are and focus on reducing the energy consumption of appliances!

3 Comments on “How to be green – appliances versus air conditioning

  1. HI Simon
    I think the focus on improving the energy consumption of appliances is important and we could adopt the Top Runner program like they have in Japan which is a step beyond MEPS.
    However I think we also mustn’t neglect house energy ratings, particularly if we can improve them for existing homes given that the average Australian home is rated at something like 2.5 stars. Adaptation to climate change through basic modifications to an existing home may be the difference between life and death, particularly for the elderly and sick.
    Furthermore, from everything I’ve read about the UK’s efforts in setting zero emission new homes by 2016, it appears to have been a successful driver for innovation. While there are differences between as built and ratings when a home is occupied, behaviour and education is also important. That’s when technology can play a role in informing consumers about off peak electricity and when we can remotely switch on or switch off appliances.

    • Hi Monica
      Thanks for the comment. Some very valid points. The climate change adaptation is an interesting one, for a couple of reasons. The first if the temperatures are likely to decrease then more insulation is better, if temperatures are likely to increase then more thermal mass like we had with the 1950s double brick houses would fair better than modern lightweight insulated houses or eskies as I like to call them. However, if the house is airconditioned and we can rely on the grid still being intact when a climate change event happens then yes more insulation is better. But the house will perform worse on the mid-season days. What is good for peak days isnt necessarily good for the rest of the year! Not withstanding that a smaller home will fair better than a larger home.
      In terms of the UK zero emission by 2016 then yes absolutely agree. The green ratings workshops we ran in October last year very much highlighted the role that regulation can play in driving innovation. And I believe tigther regulation can play an ever increasing role in Australia but that the policies that drive the regulation need to further considered. My latest post for example shows how the difference between energy per meter squared of floor area versus energy per person produces a far different view on how much regulation has driven space heating in Australia.

  2. Hello Simon, simply become alert to your this post via Google, and located that it is really informative and true as well monica suggestion. I’m gonna watch out for brussels. I’ll appreciate should you proceed this in future. Many people will likely be benefited out of your writing. Cheers!

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