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Week Twenty-Eight - Lights and Appliances

Change bulbs and behaviour to save 464 kilograms CO2e per person per year

· Weekly experiments

My kindergartner

- If you turn off my lamp, I'll come into your room in the middle of the night and I won't ever go to sleep ever again.


- That is a terrifying idea. You should send it to Stephen King.

Eyeballs staring into a dark starlit room

Household electricity

Depending on how a house is set up, it uses electricity for winter heating, summer cooling, hot water, cooking, lighting and appliances. This generates carbon dioxide and equivalent emissions (CO2e). There are two ways to cut back. Use less electricity, or use electricity that is less emissions-intense. For this week's experiment, I used less electricity on lights and appliances. Simple changes made a satisfying difference.

How much CO2e does a household generate from electricity?

The average Australian house uses 5,361 kilowatt-hours of electricity each year, which generates around 4.8 tonnes CO2e per year. My household uses 4,125 kilowatt hours each year, which generates around 3.8 tonnes CO2e per year.

How much of that is used for appliances and lights? It depends on your individual situation. Take a

good look at your bills and meters and buy or borrow an electricity meter to find your problem areas. For instance, I found out our electricity spikes during winter, which is odd given that our main heating comes from gas, so this definitely needed further investigation.

How did I take measurements?

I borrowed an ACTSmart Home Energy Action Kit from the library. If you can't get one of these, buy a thermometer, infrared thermometer and appliance electricity meter online or in a hardware store for less than $50. Better still, borrow them from a friend.

I took temperature readings of our fridge and freezer and used the infrared thermometer to check my fridge seals. I also took appliance readings for all 24 devices in our house. For that those that cycle on and off, like the heater and fridge, I took at least a one-day reading. I also took outside meter readings to see what impact my changes had on our overall electricity use.

ACTSmart home energy action kit contains electricity meter, thermometer, infrared thermometer and instructions

This kit contains an electricity meter, a thermometer, an infrared thermometer and instructions.

My four horrors - computer, heater, fridge and TV

Some devices were high-watt, like our blender, toaster and kettle, but they're not on for long each day so they barely rated. Our top-loading washing machine running cold washes was astonishingly efficient, despite its age. The tumble dryer was intense but we only use it once a fortnight so it didn't take too much power. But I found four horrors lurking in my house.

Desktop computer (generates 285 kilograms CO2e per year)

I mostly work from home on an old desktop computer with two monitors. I can't cut my hours, but I did get better about turning it off when not in use. I also now keep the printer and scanner switched off unless I'm using them. This reduced my annual household emissions by about 50 kilograms CO2e.

​Electric heater (generates 337 kilograms CO2e for the three months of winter)

We use an electric bar heater in my kindergartner's room in winter so we can shut down the central heat overnight. Ironically, we did this to save the planet, because heating one room is meant to be better than heating a whole house. #fail. That supposedly efficient bar heater wasn't. During winter, it uses almost as much power as the rest of our 23 devices combined. We've now put the heater on a timer so it's on for one hour morning and night, saving 286 kilograms CO2e. As a side benefit, my child has to snuggle under covers when she's cold rather than staying up late playing.

Editor's note: We unplugged this heater altogether as she got used to a cooler room. We'll reserve it for times when she's sick.

Fridge and freezer (376 kilograms CO2e per household per year)

Our fridge and freezer were running at the right temperatures (3 to 5°c and -15 to -18°c). It was also well-ventilated and located in a cool spot, but the cracked seal was leaking heat. The fridge is over 10 years old and might be worth replacing. I ran some back-of-the-envelope calculations and the embedded emissions in the device may well be offset by power savings over a year or three, but I was feeling end-of-tax-year poor so I got replacement seals instead. This cut the power use in half, saving 185 kilograms CO2e per year. We should have done it years ago.

Two people play a computer game

TV & games console (379 kilograms CO2e per household per year)

Our TV and games console chug power at a whopping rate of 1.1 kilowatt hours per day. Netflix is key entertainment for us, so rather than deprive ourselves we unplugged the bits of the system we don't use. This saved 38 kilograms CO2e per year. If we need to make more savings, I'll look at one or two screen-free days per week. Great as a digital detox but not sure how my tribe will take to it!

End-of-life replacements

When replacing my dryer, microwave, dishwasher, computer, fridge, TV and heater, I'll seek out the most energy-efficient models I can find. Depending on your situation, it may be worth replacing some of these items before they break. It's also worth consolidating (ie. run one fridge, not two).

What about lights?

My partner assured me our light bulbs were already energy-efficient. He was wrong. We didn't have any old incandescents as these got phased out a decade ago, but most of our bulbs were halogen. We missed the memo that CFL lights are better and LEDs better again. We've now switched over. I didn't separately meter this but I could tell from our overall readings that it made a big difference. The quality of light is also nicer and the tech has improved since the old days.

We already turn off lights when not in use. I tried a new system of switching off my kindergartner's bedside lamp overnight. I failed. Sometimes real life defeats good intentions.

Incandescent, halogen, CFL and LED lightbulbs all use different amounts of power

Incandescent, halogen, CFL or LED? If you don't know, it's time to check your bulbs.

How much CO2e did I save?

This week's changes cut 30% from overall my electricity usage, which saves 266 kilograms CO2e per person per year from my footprint.

Savings for other households depend on particular circumstances. Most estimates I've read assume cuts of 5-25%. Based on my big impact / little effort result, I'll assume the 'average' household will save 25% of their electricity usage by following the steps below. This should slash 464 kilograms CO2e per person per year.

1) When replacing devices, buy very energy-efficient on the big power users (heater, TV, desktop computer, fridge, dishwasher, microwave, dryer). Worry less about low power devices.

2) Swap out all bulbs for LED, or CFL if you can't find LED. Replace new for new, don't wait for them to break. Embedded emissions are small and power savings are large.

3) Consolidate your devices. Cut down the number of TVs, fridges and desktop computers.

4) Use an appliance meter to find your big power users. Make changes and see what happens.

5) Check standby usage. This wasn't significant for me but might be for you.

6) Be careful with any device that heats or cools. Check power use in action and don't assume that heating a single room is efficient.

7) Check out resources like ACTSmart Energy Saving Guide and do a whole house audit.