Casting away carbon, street by street

Better energy efficiency initiatives, less gas-fired appliances and more rooftop solar could take us drastically closer to zero emissions in our homes.


   
Australia's homes are among the largest and most inefficient in the developed world. Then we wonder why our household energy bills and carbon emissions are so high. 

There are, also, few ways we get feedback regarding our household energy consumption meaning we are mostly 'driving blind' when it comes to energy use and emissions from our homes – we get a bill at the end of the month or end of the quarter, far past the time the energy was actually consumed. The lack of instantaneous feedback makes it difficult to correlate our energy consumption to a particular event.

An inefficient home is also uncomfortable, it is draughty, damp, too hot in summer and too cold in winter. Live in North America or Europe and you will know what an energy efficient and low emissions home is like, and the opportunities that exist for energy efficient homes in Australia.

Our homes are a ripe area for direct action, with real benefits for the climate, our comfort levels and for our hip pockets.

Beyond Zero Emissions has estimated that implementing its Zero Carbon Australia Buildings Plan could reduce Australia's emissions by more than 15 per cent, or 90 megatons of CO2-equivalent. Implementing the plan relies on a combination of energy efficiency initiatives, replacing gas-fired appliances with efficient electric alternatives, and the widespread uptake of rooftop solar.

Implementing the plan would also see household electricity use decrease by about 10 terawatt hours per year. This is almost as much the annual output of Victoria's Hazelwood power station – the country's biggest emitter – which has an annual output in the order of 12 TWh. So, in effect, the implementation of the plan in homes alone would replace the output of about one large coal power station.

On the other hand, replacing just one coal power station may seem underwhelming for a zero emissions plan but, remember, this reduction only relates to the energy efficiency opportunities in homes and does not include energy efficient initiatives in non-residential buildings. In addition, the reduction is after all gas appliances have been replaced with more efficient electric alternatives. 

And then we add the effects of rolling out 33 GW of rooftop solar, based on modelling Beyond Zero Emissions has done on rooftop solar potential across houses in Australia. This would effectively replace the output of another four large power stations – generating about 49TWh a year. There are already over 1 million homes with solar PV on their roofs, so significant action is already being taken by households and this will increase as the cost of PV continues to decline.  

It is important to note that the buildings plan is also affordable over the period most people own their homes. Our economic modelling shows that over a 30-year period, the cost of implementing the plan will be recovered in savings on energy bills.

Installing all that solar PV and going 'no gas' also turns houses into net energy producers and provides the prospect of energy freedom. A recent study reported in The Age showed that more than half of home owners planned to renovate in the next four years, with an average budget of $16,130.

The highest cost scenario for implementing the buildings plan in a home is $45,000 over the projected 10-year implementation period, but most homes would be significantly beneath this cost. If you consider how much some people are already spending on renovations, there is enormous potential in incorporating significant energy efficiency measures into those renovations.

How to ensure all homes can do it (not just those who can afford renovations) is a broader policy question. But for the purposes of this piece, the potential emissions reductions make it worth pursuing, and even more so as the investment required is well within the bounds of possibility when compared to business-as-usual.

Energy demand in households is already falling, so much so that the head of AGL Energy, Michael Fraser, said last July that Australia should retire 9 GW of baseload generating capacity from the grid. In this context the findings of the buildings plan emphasise the impact household actions can have (and, have already had) on emissions (see: Baseload fossil fuels no longer needed and The great de-electrification).

It appears that many Australians are already taking 'direct action' in their own homes and this is great news. We should recognise this and celebrate it – and ask that the government come to the party to realise the full benefits.

So rather than the traditional saying that building energy efficiency is 'low hanging fruit', it is also capable of handling some of the heavy lifting in emissions reductions.

Dr Stephen Bygrave is chief executive of Beyond Zero Emissions. He has worked nationally and internationally on climate change for 20 years.

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