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Week Twenty-Four - Household Energy

Household electricity emits 2.1 tonnes CO2e per person per year

· Weekly experiments

My kindergartner

- I know there's electricity in my lights but I just don't know how it got there.


- You and the rest of Australia...

Cartoon kid asking how electricity works

How much carbon does electricity generate?

When we switch on the lights, most of us don't think about electricity. We should.

In 2016, electricity was responsible for almost 195 million tonnes of carbon dioxide and equivalent emissions (CO2e). That's around 8 tonnes CO2e per person per year or around one-third of Australia's total emissions.

Electricity Status: It's Complicated

In Week Ten, I thought I'd cover household electricity. It turned out to be complicated.

'You need to spend more than a week on this,' said my carbon economist friend, Salim Mazouz. 'Energy policy in Australia is massively complex and it's constantly changing. If you rely on good information that's six months old, you're out of date.'

Salim's educated view was that coal is out and renewables are in, no matter what governments do. I was delighted to hear this but confused. If that's true, why is there so much noise about coal? Why are we building new mines?

Salim explained that governments don't understand how fast renewables have progressed because they're looking at old data. The world has relied on coal for decades and our dependence only declined slightly in that time. But if you look at the last year or two, the line changes.

'If you're driving on a straight road, the rear-view mirror is a good guide to what's coming up ahead,' Salim said. 'But it's useless when there's a bend.'

Where does our electricity come from?

Most of Australia's grid power currently comes from coal, with renewables providing only 18%. These renewables include big hydro, big wind and big solar as well as small rooftop and community schemes.

Chart showing the different kinds of fuel powering Australia's electricity grid

The coal industry loves reminding us that they're keeping the lights on, but they ignore the uptick in renewables. The chart below is based on Clean Energy Council data (which is similar to government data).

Chart showing the rapid growth of renewables in Australia's electricity sector

The 2014 to 2018 data show renewables starting to spike, particularly last year. Renewables generated 17% of the grid in 2017 and 21% in 2018. If this growth rate continues from 2019, we see a rapid transition away from coal, even without government intervention. I've spotted Salim's bend in the road.

What about household electricity?

Electricity may be responsible for around 8 tonnes of CO2e per person per year, but not all of that is used by households. My household uses around 4,100 kilowatt hours each year which, if taken from the grid, would emit about 3.8 tonnes CO2e (1.3 tonnes CO2e per person).

It's difficult to set a per-person average because households vary so much. Consumption is higher for houses with slab heating, pools, electric water heaters and more rooms than people. Big households are more efficient and group housing beats solo occupancy (but don't take that as a reason to have more kids!). Tasmanian households use more electricity, but their hydro-powered grid emits the least, over five times less than coal-dependent Victoria.

The government's Energy Made Easy tool lets you compare your electricity usage with the average in your area. For my 'average figure', I'm looking at a 3-person household in my ACT postcode of around 5,900 kilowatt hours, emitting around 5.4 tonnes CO2e each year (or 2.1 tonnes CO2e per person). It would be four times higher if I looked at a solo household with slab heating in a wealthy suburb.

How will I cut back?

There are two broad approaches - use less power or change the power source. I'll try both methods over the next few weeks. I'm not looking at summer cooling or winter heating as I've covered those elsewhere.

- No gas. What would happen if I used only electricity and no natural gas?

- Appliance efficiency. How much electricity do lightbulbs and appliances use? How do I cut back?

- Hot water. How much hot water do I use and how do I reduce its emissions?

- Choose renewables. Rooftop solar, community schemes or Greenpower? What's the best choice?

- Best of the rest. Do heat pumps, smart devices and other clever tricks make much difference?

Join me over the next two months to find out you can slash your electricity footprint.

Coal is dead and it's time to get on the right side of history, say #StopAdani activists.

Spreadsheet calculations, notes and data sources in the 'Notes' section, Week Twenty-Four.