29 September 2013

Reducing Energy Usage

I think this post is going to be one of those where you share embarrassing information in an attempt to force yourself to make improvements!   

In my August Slow Living Journal I talked about my realisation that we need to reduce our electricity usage in the City Garden house.  When I think about it now just one month later, it seems crazy for me to say that I have only just realised this, but there have been so many reports in the media over the last couple of years about the increasing cost of electricity in Australia, and our electricity bills have been expensive, and rising even further, so I just assumed that we were pretty average and everyone has had the sort of bills and energy usage that we have.  But no, actually, it turns out that lots of people don't!

Step 1: Understand that there is a Problem
According to my energy company the average daily power usage for a two-person household without a swimming pool is 14.3kWh (kilowatt hours).  OK, so the first step to a solution is admitting you have a problem isn't it?  So bearing in mind that we don't have a pool, air conditioning or electric hot water and only have one TV and hardly any other appliances in a tiny house... here goes... our average annualised daily usage is 19.2kWh and our most recent winter average was a staggering 36.65kWh!

Even seeing those numbers on the last bill didn't make much of an impact until I went on a site visit a couple of weeks ago for the Permaculture course to a similar house to ours with an average usage  of 1.5kWh.  With a 1kW solar system installed, in the last year they received about $500 feed-in tariff refund, which paid for all their other utilities bills for the year.  

Step 2: Identify the Details of the Problem
I had borrowed a Powermate from the library to track where the power was being used, but still didn't really understand the problem.  At this point I realised that I needed some professional help.  With the help of the Sustainability Officer from my council I have spent the last month rechecking the usage and putting it into a spreadsheet that he gave me that clearly shows the breakdown of usage across the household.  This allows me to see the big problems and target those for reduction.  I understood that our  heating was probably the biggest user, but was completely unprepared for the impact that it actually has:

The Top 5 electricity gobblers in the house by percentage are:
  • 60%  oil panel heaters  
  • 14%  oven
  • 6.5% LV downlights in kitchen/living/dining 
  • 2.6% bathroom fan heater 
  • 2.1% security system
We had deliberately purchased oil panel heaters with thermostats (a 2400W for the living/dining room and a 1000W for the bedroom) as I'd understood that electric heaters without fans are more efficient.  I now realise that isn't correct, and that logically it's the amount of time that you have them on that chews the power.  With both our heaters running from 5am-9am and 4pm-10pm through the winter (10hrs a day) their average use is approximately 12-15kWh/day.  Even though the heaters have thermostats so will turn themselves on and off during that time in theory, the spaces they are heating are so inefficient that they are running almost constantly.

Step 3: Identify the Potential Solutions
Once the biggest issues were clearly set out I went through the list and identified where changes could be made to reduce the overall kWh usage.  That indicated that it should be possible to make a saving of 70%, reducing the daily average down to 10.3kWh. 

While some of the solutions are quite high cost, they would actually pay for themselves very quickly against the rising cost of electricity (our winter power bill was over $900).  The biggest is clearly to change the heating system to gas.  But from discussions with the Sustainability Officer I now better understand that we also need to get smarter about how we heat.  Drafts need to be stopped up (the house is full of gaps and cracks), windows need to be better insulated, and spaces need to be contained so that we are only heating the areas we are using.

Step 4: Implement the Solutions
The Target by next winter:
  • Reduce power consumption down to a daily average of 10kWh
Within the following year:
  • Identify further ways (probably more via changing habits) to reduce the usage down to less than 7kWhs so that a 2kW solar system would meet our needs and have that installed
  • Identify whether there could be any further reductions so that we could actually make money out of a solar system or even be capable of living Off Grid.  The challenge to beat seemed to be the site visit house that averages 1.5kWh, until the Sustainability Officer told me that he's got his house (and he has kids) down to 1kWh!!
Ethics of Reducing Energy
The discussion above is all written around saving money, as that seems to be the most tangible way of understanding the impact that our behaviour is having.  But ultimately the aim for all of us has to be to substantially reduce our consumption of all energy and impact on the Earth's resources.  So I understand that actions such as replacing electricity with gas are a step on the way rather than the ultimate solution, and that changes of habit and lifestyle, along with education will play the major part in ethically reducing impact.

I also understand that many people have been thinking and acting on this for a long time, and I've been embarrassingly slow to take action.  Have you been undertaking actions to reduce your energy impact?  It would be great to understand what other people have found to be good solutions and practices.  If you've written a post on it or just have some great suggestions, perhaps you could post a link or write about them in the Comments and I'll set up a new Page with links and ideas.  I'd also be happy to share the spreadsheet that I've been using to track electricity usage if it might be useful to you.  Just send me an email and I'll forward it to you.


  1. I'm proud of you for sharing! Good luck with the reduction mission.

    1. Thanks Anneli. You do so well with this stuff, perhaps you could share some tips?

  2. We've had a similar recent experience, so thanks for sharing your ideas. I've just put a powermate on hold at out library thanks to your tip and I'll be sure to get onto our council to get some advice.

    I've written about our experiences here http://thenewgoodlife.wordpress.com/2013/09/30/when-money-matters/

    1. Thanks for sharing your post Barbara, I'll set up a new page and try to track some energy saving ideas. It's definitely worth drawing on the resources of your local council if they have a sustainability officer employed there.

  3. Interesting post. What's a blog for if not to reflect and spur yourself into action?

    Your point about thinking in terms of saving money rather than "the bigger picture" is, I think, really salient. Money provides a quantifiable, tangible measure of consumption, and I believe, up to a point, saving money = living more sustainably. If everyone set out to cut their monthly expenditure by, say, 50%, then I think we'd make some good progress towards a more sustainable future.

    And, paradoxically, I think most people would be happier. Tim Kasser makes a clear link between over consumption and unhappiness in his book "The High Price of Materialism".

    Cheers, Chris

    1. Yep I think you might be onto something there Chris, and thanks for the book tip. (Glad you managed to negotiate the security thing, thanks for persevering!)