What Energy Efficiency Improvements Have You Done, and How'd They Turn out?

Hi all,

Just wondering what energy efficiency projects others have done around the house? What's worked, what hasn't? What was worth the cost, what wasn't (in purely financial terms of saving more over time than the capital cost).

Also interested in solar PV systems and battery storage experiences (even though they're not really efficiency improvements per se), especially increasing size of preexisting PV systems.



  • +2

    Hunting down and fixing draughts was good. As was replacing windows with double glazed ones (spensive tho).

    Replacing halogen lights with leds (no more replacing globes endlessly, modest power saving and fixed holes in insulation in the roof).

    Ditching the 20 year old gas heater.

    • I like hunting out draughts when there's a blackout

      • Why during a blackout? Because that's when you have a candle out?

        • +2

          Well, the internet is probably out and it's too dark to read (not that you have books anymore anyway) and you need something to occupy the time. (No you don't have a partner, the ROI is poor and this is OzBargain.)

          I was rather astonished at finding out how much a small gap can do. At one job we were too lazy to unlock the server room door, so we'd stick something in the doorway to keep it slightly open.

          The gap was small so it wouldn't make much difference, right?

          Well, I came across some temperature monitors and sat one in the server room and the rest around the office, and found even though the air conditioners were running non-stop the temperature in there was about the same as in the general office area.

          We stopped doing that, and funnily enough our air conditioners stopped breaking down as much. The bill probably went down as well, but that wasn't my problem.

          So yeah, sort out the gaps first.

    • +1

      Double glazing is something I'm very interested in. Do you mind if I ask how much it cost and what size the windows were? How effective is it in terms of heat loss/gain? Being ACT I guess you're probably more interested in retaining heat inside?

      Our master bedroom has windows facing directly west, and this is one of the things I'm considering to reduce heat gain through them. I'm also considering just a window film, rather than full double glazing. Obviously wouldn't be as effective, but might be ok combined with something like an awning on the window…

      LED's is a no brainer too as you say, especially if you can get the whole house done for free!

      • +2

        First thing you want to do is stop the sunlight hitting the glass, so plant a tree or put up some shades.

        • Absolutely. I'm planning on at least the tree and outdoor blind and maybe window film. Because of the block though a tree is a 10-15 year plan, hence the blind as well.

        • +1

          @therog1: Someone once pointed out to me that the window film should go on the outside of the window. That way the light doesn't have to travel through the glass and so heats it up less.

          Not something that had ever occurred to me, but makes perfect sense.

        • @D C: That's the plan!

        • +1

          @therog1: Not sure how long the tinting would survive outside in the weather.

          As a slightly related data point, I once hung a couple of those mylar 'space blankets' (the silver/gold stuff) over a west-facing window with no shade. It did actually knock a few degrees off the room temperature.

          I didn't do it properly by taping up the edges to make an air gap, so it could have been better. I should try it in winter to see if it keeps the heat in instead.

        • @D C: That's a very interesting idea, thanks!

    • You must live in Tasmania. I don't understand anywhere in Australia where these would be good ideas except the cold climate of Tas.

      Edit nvm, Canberra. I guess that's "kinda warranting" it.

      People in Australia really do feel the cold too much…

  • +1

    Redoing THE Hot Water system

    Linking my Solar Panel system with the electric hot water tank via a Solar Diverted AI hardware (Paladin)

    • Cut of electricity grid at Night to heat up tank
    • Only used solar to heat up tank
    • Act as a battery for excess solar production
    • Heat up to 60c, which last throughtout the night from 6pm.
    • Yes, this is pretty high on my list too, but I'm just waiting to get a bill or two to see what the damage is and how high of a priority it is. But with a new hot water heater for $99 (or $799 for a big one), it's almost guaranteed to be worthwhile!

    • I would have it set to 65c minimum. There's a good reason for that. One of them being why hospitals have to put disinfectant through their water supply systems every so often to combat bacterial growth, as they run their hot water supplies under the minimum recommended temp.

      • +2

        Over 55c is a scalding hazard, what you do is run the tank at 65-70c but add a mixer to set the temperature of the water that comes out the taps.

        Some tanks (a bit rare, I think) already have this, you think you're setting the temperature but really your just adjusting the mixer. The real temperature control is hidden inside the panel.

    • I am very interested in ways to turn things on and off depending on how much power I am producing. I did a search for a paladin and heaps of irrelevant results came up can you post some info or links on how you did this.

  • +3

    Not ever having to pay for gas due to the supplier's metre issue. Have told them 3 times I'm only paying daily supply charge, once over eamil but nothing happned. It's now been 3 years and nothing. Ombudsman says they can only harge back 9 months and give 9 months to pay it, but they don't have proof of what I've used.

    I've also stopped draughts, changed all lights to LED, gone from electric hot water to gas instantaneous, removed an old split air con and installed new high star rating Fujitus and replaced 20 year old gas ducted heater to new 5 star gas system. I still love long, high pressure showers so that bill is big but worth it to me haha.

    • +1

      Haha nice! Billing error in your favour, collect $100.

      How old was your split system and what sort of payback time did the new one have?

      • It was more a safety thing too. The old system was installed by previous owner and wiring was terrible and it pointed at a very close wall and didn't cool whole area. New better one, installed properly that blew air in the whole area was main decisions.

  • +11

    I employ a one light policy per person. Violations of this result in financial penalties.

  • +1

    6kw Solar system
    Ditched click energy for Alinta

    • Yes, I have a 1.5kW, and I'd like to add more panels, but currently getting 61c FiT and I'd lose that if I upgraded.

      Need to get a couple of bills and run the numbers…

      • +1

        I’m the same. Still cheaper to keep the 1.5 and old rate. In five years when the 61 cent tariff ends then you upgrade and maybe batteries will be cheaper.

        • Another 10 years for us I think…

  • +2

    I moved house…moved from a 1 star house to a 7 star house.

  • +1

    Upgraded to:
    Led lights
    Instantaneous gas water heater
    Thick window curtains during summer
    Reduce aircon only when necessary e.g +35 degree heat. Bought 5 bunnings fans for $10 each which cools the house in the evenings.

    Definitely help add a few extra $$$ to the piggy bank.

  • +2

    Reckon draught proofing is great investment. Put aircon on much later in day. Mades difference in maintaining warmer temperature inside
    Also insulation in roof and solid brick wall cavity.Double glazing too expensive for me so have installed some internal cellular blinds againt glass and retained ordinary blinds in front. Upgraded solar panels to 6 Kwh system. Over summer and using Powershop I have credit. Only on ordinary FIT. Now need to seal bathroom heating light and LED lights which leak hot air into roof cavity and more cellular blinds. Saves on energy bills. Also use deciduous trees and vines and wide eaves. Live in Melbourne.

  • +1

    Installed solar PV, 2.4kw halved our power bills, but we manage our usuage a bit more than most people, load shifting where possible to reduce exporting power.

    Tinted windows on the house on the side that gets the most sun.

    • Are you planning to add more panels later, or happy with 2.4 for now?

      • +1

        no plans to add any more, we export a lot of power. At the time we paid $4500 for this system, now we would get a system double that for the price. This was also the most amount of panels we could have facing north. Any additional panels would be west facing .

        If I got one now I would just get a 5kw system which is the largest you are allowed to have and still export power (in my state).

  • +3

    I save a fortune on the winter heating bill simply by not having a wife.

    • I would have thought you'd save money with a wife (partner in bed keeping you warm)

      • +3

        You obv. don't have a wife :)

      • Not if they have a stone cold heart.

  • +1

    Switching to lower Tariffs on certain appliances, some on timers.

  • +1

    When we renovated 4 years ago we did the following;
    1. Replaced normal glass for E-glass. It added 10% to the window bill and made a noticeable improvement improvement in keeping the inside comfortable. We looked at double glazing and found it too expensive. If we had needed to keep sound out we would have used double glazing. Extra cost $3000.
    2 Replaced all lighting with LEDs Extra cost then $1500.
    3 Replaced air conditioning with inverter reverse cycle. Extra cost $3000.
    4 Installed 6.4kw PV panels. Cost $8200
    All up we save $250 per month in electricity and do not skimp on using electricity to make us comfortable.
    I would do the same thing again

    • Nice. That gives a ~5.25 year payback period which makes it ~15% annualised ROI.

  • +2

    I have a complete home RE system recently extended. I'm on a high Feed in Tariff (47c/WA. So to maximise my earnings, I have rewired my switchboard such that the PV system exporting is on its own dedicated phase. The rest of the house (apart from the 3ph bore pump being serviced by all phases), is covered by the other two phases. I have a 6kwh home storage battery (its part of a trial) and my 23kwh EV sits under a carport with PV above. I have 10kw of panels (4.5kw for export) and my EV is used as a buffer to keep the home battery topped up. All my motoring fuel needs from the sun, same for the house too and I get ~$3500 back from the power company which pays my rates and water. All my extended system was built from second hand gear as the home network is considered 'off grid' with grid failover for backup. Costs are 2011 3kw system $4600, extended 1 year ago with 6x s/h panels, cost $500 - all wiring constructed by my and the sparky did the connections (cost $250). The extension system of 40x panels bought for cheaper than (s/h) roofing iron and <$1000. The hybrid inverter cost me $2200. I got a cheap system by doing a lot of the work myself.

    • That's a great setup! I'd love to be grid independent, but not likely to be possible in my current property (mainly because of space constraints).

      • +1

        Yes, thats a big problem unable to resolve. I will only go off-grid when they stop paying me huge bucks for my exports. Soon as that stops, I'm outa here and entirely off-grid. The good thing is in the meantime I have 3 years to bed my present extended system in before cutting the wires and telling the power company I'm contributing to the death spiral of their centralised power generation.

        • Yes, I pity those left holding the buck at the end of the day. It will be those who don't have the resources to afford things like solar (or, more appropriately, afford their own house to put it on), who are also incidentally the ones who would get most benefit from it! The less people reliant on the grid, the fewer people to spread the cost of it. Great for those who can afford to bail out, not so much for those who can't!

    • Love to know more about this. Just bought a house with 5kW solar. feed in is only 16c. Considering buying an outlander eV and use as battery storage. Just not sure how / limitations.pm me if you have any tips.

  • +1

    mainly just switched out all our halogen downlights (30 bulbs all up) for 5w LED ones. Was $400 worth of bulbs but by my calc that will pay for itself within the year in electricity savings.

    • Yeah downlights especially are a no-brainer!

  • +1

    When I switched all our incandescent globes to cfl I didn’t really notice the bill difference, but know I’d gone from a bunch of 100w globes to 10-15w. Now we’ve got a house full of LED lights.

    Biggest difference was installing solar.

  • I dont know because they keep puting up the rates.
    Impossible to compare with last year in terms of cost.
    Would need to compare kwh used……Too hard

    • +1

      It will be on your bills. Mine even include a graph showing average (or maybe total) usage per quarter for the last several quarters.

  • +1

    You can fiddle while Rome burns, at great expense too, or you can take a single, no expense step that will reduce your carbon footprint more than any other.


  • +2

    We are in a small apartment block which has a lot of lights on all the time - entrance, lobby, fire escapes as well as a few lights triggered by motion sensors. In all in excess of 30 lights. We changed them all across to LED a year ago. We have experienced a 30% decrease in electricity usage. All up it cost about $3,000 labour included so will repay that in less than 2 years. Now to tackle the draughts!

  • +1

    Installing solar hot water. Took the electricity bills down from $300 a qtr to $150-$200

    Its a shame the cost has been inflated so much, because the materials are fairly cheap and they make a huge difference

    • +1

      Our hot water bill component is like $30/qtr in summer and $70 in winter. Off peak is cheap, it's going to take a fair while to break even on a solar hot water install.

      • That's pretty impressive. Is that gas? Or heating on your excess solar PV output?

        • Just straight off peak electricity. It’s easy to measure as it is a separate item on the bill.

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