Use Case: The Electrical Bill From Hell

Recently I got a call from a family member asking if I could recommend a good place for them to buy some solar panels to put on their house. They are getting quite expensive power bills and wanted to get in on some of that sweet, sweet free electrical power that rains down on all of us for free (not to mention doing something good for the environment in the process). So of course I said yes and got her to send through their electrical bills and usage patterns over the last year so I could dig into them and give them an idea of how much they’d likely save.

After starting to write up a response it started to get a bit lengthy and I came to the realisation that many of you out there might also be in a similar situation so I thought, why not make a post about it so everyone can enjoy the answer? I’ve gained a fair bit of knowledge over the past 4 years getting our 3 bedroom house down to using about 4 kWh’s per day on average so I’m sure there will be something below that will help everyone cut their power bills and Mutilate Their Mortgage more efficiently.

Their Usage

To start off with this family member has a good sized house with 3 bedrooms, an office, big living area, big kitchen (with dining area) and a swimming pool (with outdoor entertainment area). They have 2 children (both under 7 years old) and they also run a business out of the office which means they have 2 computers on quite often.

Next up let’s lay out their usage over the last year or so:

2012.05.30 to 2012.08.24 – 63.05kWh’s/day <- Cold Weather
2012.08.25 to 2012.11.22 – 38.28kWh’s/day <- Mild Weather
2012.11.23 to 2013.02.27 – 55.87kWh’s/day <- Hot Weather
2013.02.28 to 2013.05.29 – 51.03kWh’s/day <- Mild Weather
2013.05.30 to 2013.08.27 – 37.21kWh’s/day <- Cold Weather

Yikes! This gives them a yearly average of around 49kWh’s per day! At the rate they pay, that’s just under $12 each day being spent on electricity alone or about $4,300+ a year. It was at this point I enquired about how exactly they used this electricity. I got the following answers:

We have a gas hot water system.

We normally heat our house with ducted heating (gas) and reverse cycle systems (split system air con) in the kid’s rooms, on most nights during Winter.

We normally cool our house with reverse cycle systems (split system air con). We have them in the kitchen, lounge, office and both kid’s bedrooms. They are on if it’s really hot but not so much the office. The kid’s ones are only on at night.

We have a gas cook top and an electric oven.

We have a pool with solar heating that is turned on only in Summer.

We have a fridge in the kitchen, a spare fridge in the laundry (full size) and a bar fridge out site which are all on all the time.

We have 2 computers that are on almost all the time in the office as well as various AV boxes for the TV which is also on from about 4pm onwards each day.

We use the washing machine every couple of days for a few loads. The dryer will be used for maybe 4 loads a week for an hour each load.

We have energy efficient lights in the majority of the house, but not in the kitchen and lounge area, they are spot lights.

Now obviously I don’t expect a person with a bigger house, 2 children a business running all day and a pool to get the same power usage as what we do. But whilst I was reading this it gave me both chills and a good feeling because I knew that this massive cost could really easily be reduced! By changing a few specific habits this family could (I think) recoup roughly two thirds of that money and use it for much more productive purposes. All we need to do is help educate them in the wise ways of proper energy management. So let’s get at it!

To Solar Panels Or Not To Solar Panels

Originally I was asked if I could recommend somewhere for them to buy Solar Panels from. So I’d just like to quickly point out that because this energy usage is SO high and because it’s costing them SO much money, they are much better off concentrating their efforts on minimising power consumption for now. For example, given they have 4 people in their house they should be using around 18kWh’s/day according to a handy government website.

Once they can get their usage around the 20kWh’s/day range THEN it’ll be smarter to buy some solar panels. The added bonus is that for now, solar panels keep getting cheaper and cheaper so the longer they wait, the better!

Heating And Cooling A House

Basically you never want to actually use your heating/cooling devices. I’ll be frank. Just put on more clothes or a blanket. If your house doesn’t have full insulation go buy and install some, it’s worth it and will be some of the best money you’ll ever spend. If you’ve already got insulation then you’re just going to have to turn the heating split systems off.

There’s no reason to have a heater on during the night. Ever! If you’re cold in bed, again being frank, get a blanket. Still cold? Get another one. Still cold? Put more clothes on. Still cold? Deal with it. One good trick is to have a heater blanket that turns off after 15 minutes or so.

That way you have a nice warm bed to get into, you can fall asleep warm and then it turns off and you’re right for the rest of the night. Either way though those split systems heating the kids rooms (or yours) is I’m guessing what’s causing your bills to spike during the Winter times (63kWh’s/day). You shouldn’t be turning on any heater until you’ve got at least socks, shoes, shirt, jumper/jacket and a blanket on (if you’re sitting down).

A good trick I use is if I’m feeling cold in the house ask “what would I wear outside right now?”… then I go put that on. If I’m then STILL cold inside the house with my outside winter clothes on then I might get a blanket on me. There’s just no good reason to heat an entire house (or large portion of a house) when you can just rug up yourself a bit.

When it’s hot, replace turning on the split system with opening the windows at night. We also put a fan in front of the window that sucks in cool air from outside all night. I’d recommend any generic ~50cm desk fan, they are about $20 from Kmart. If you or the kids are REALLY hot during the night a great trick I use is to have that fan blowing over my body.

I get about as hot as most guys do and I’ve slept with the doona on during 25 degree nights with our fan blowing over me. They’re GREAT and use less power than a light bulb. Turn off ALL heating/cooling devices at night (and most of the day) and instead use fans or jumpers/blankets.

I can’t stress this area enough as it really sounds like one of, if not THE major reason your bills are so high all year. It’s a change of life style yes but it’s one you will adapt to without much fuss after a while. Next up are the other two issues…


You have too many fridges! I’d suggest either selling the outside bar fridge and inside laundry fridge completely or at the VERY least cleaning them out and turning them off for most of the year. I’m pretty sure you don’t have parties that often (at least not ones where all the fridges are needed) so if you are having a big shindig that requires the spare fridge you can turn it on the night before and it’ll save you a lot of money over the year. Same thing for the outside bar fridge.

ou might also want to check the seals on all the fridges to make sure they’re all good and not leaking cold air out. Selling/turning off the two spare fridges is actually a very “quick win” that I’d suggest doing literally, right now. Another very easy option is to sell the second big fridge and then when you have parties just buy a bag of ice and put all the drinks in the laundry sink with the ice. Whatever you do though, both those fridges should be turned OFF 99.999% of the year from now on.

Washing Machines And Dryers

In our house we don’t even have a dryer and I can tell you it’s no problem and never has been. Hang your clothes on the line during Summer and hang them on an inside clothes hanger in Winter (or all year round if you’re lazy like us). I’d recommend something like this or this. They are about $15 at Kmart and those versions are quite stable from what I’ve seen, long lasting and hold a lot of clothes.

We normally store the clothes line in a room and just open a window so air can circulate and not get stale. You’re doing 4 loads in the dryer each week and that is costing you a LOT. I understand you have 2 kids and they make a mess and you might have to use it sometimes when things go really crazy but the vast bulk of your washing should be dried without the dryer.

This Electrolux 5kg Sensor Dryer uses “222kWh’s/year” according to the specs which means that it uses 222 / 52 = 4.27kWh’s per load. If you’re doing four loads a week that’s (at your cost of power) about $4.25 every week or $221 each year. Now that doesn’t sound TOO bad but this is a TOP rated energy efficient dryer and only 5kg. If yours is bigger, older, has less energy efficiency or is all three then your costs are likely even more.

Computers And AV Equipment

Computers should be turned off. Whilst these don’t take up as much power as some of the above items they are on 24/7 a lot of the times from what I know. If you’re not using them, turn them off. You can put them into hibernation which makes them turn back on quicker or you can just turn off completely. Generally speak an average desktop computer will take up about 300W’s per hour when on not including any monitors. At 24/7 that’s 7.2kWh’s for EACH PC.

Laptops take up a good deal less but they are still using a lot of power. For comparison we use less than 7kWh’s each day for our whole house. I’m not saying never use the PC’s again as you have a business to run but get in the habit of turning them off just like you would a tap when you are finished washing your hands.

AV Equipment is also normally on 24/7 and so is likely a decent daily drain on your power. I’m not entirely sure of your setup though but perhaps investigate cutting back on the number of devices or even have them all running off a single power board so that you can just flip 1 switch and EVERYTHING goes off not just the TV.

Swimming Pools

Swimming pools are normally an incredible drain on power use however you’ve already stated that you heat it via solar heating and turn it off completely during the Winter. I would suggest investigating how much power it uses by reading the label on the heating pump.

Power (in Watts) = Voltage * Amps. So if it’s 240V and uses 10 Amps that’s 240 * 10 = 2,400W. If you use it for 1 hour, that pump will use 2,400Wh’s (or 2.4kWh’s). It’s pretty simple. As I’ve already said though, I suspect the pool is likely doing fine and that it’s your use of heating/cooling that’s really making your bills huge so I’d focus on that part first.

Everything Else

Given that you have gas hot water, gas cook top these and CFL lights in most of the house there are likely not huge savings to be made in these areas. There are savings… but you should focus on the bigger items first and then go down the list to these smaller things once they’ve been taken care of.


As a general summary and guide I’m going to recommend the following:

  1. Clean out and turn off the second fridge and bar fridge. Only turn them on for parties or just sell them completely.
  2. Stop using split system air conditioners to heat/cool the house at night full stop. Learn to survive without them during the day as much as possible with more clothes/blankets or fans.
  3. Dry your clothes on an indoor drying rack and reduce your dryer use as much as possible.
  4. Turn off all computers when they’re not in use and try and structure your setup to not have them on all day/night.

After this, recheck your power bills and see what your average daily use is. Once it’s closer to the 20kWh/day mark start investigating solar panels. I’d recommend nuEnergy as they installed our system and did a flawless job. We haven’t had any issues in almost 4 years and although one data point isn’t the best basis for a recommendation they also have been around for over 20 years apparently which is much longer than most solar panel installers.

For 20kWh’s you could go as big or as small as you wanted. A 5kW system might produce around 20kWh’s / day on average or about 7300kWh’s per year so would almost entirely eliminate your bills (assuming you got your usage down to 20kWh’s a day).

So get to killing that bill!

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