Wednesday’s IEEFA report projected that households could make savings of between 82% and 94% if they:
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Installed an 8kw rooftop solar system and a 10kwh battery
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Used reverse-cycle air conditioning instead of gas or electric heaters
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Swapped gas or old electric water heaters for heat pumps
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Replaced gas cooktops with electric induction
The IEEFA modelling did not take into account the further gains that Gordon said can be made by improving the thermal efficiency of homes: how well they can hold heat in the winter or keep heat out in summer.
More thermally efficient homes give households the option to use more daytime energy from solar to either preheat or pre-cool their homes ahead of the evening peak.
Menzel said though technologies such as heat pumps and solar are well established, policies to encourage their take-up are a challenge.
“With electrification and efficiency you’re talking about a much broader range of product types and interventions that look different in different parts of the economy,” he said.
“It’s a heavier lift, but it’s where we need to go.”
Australian homes use about a quarter of the country’s electricity, and account for more than 10% of greenhouse gas emissions. Cutting gas use in homes could also ease the supply pressures in the east coast, Menzel said.
Two reports in 2023 and 2024 from the independent Climateworks Centre, based at Monash University, have made the case for a “renovation wave” across homes in Australia, especially those built before 2003 when minimum energy efficiency rules were introduced to national building codes.
Steps such as upgrading windows, adding insulation to walls, ceilings and floors, and upgrading appliances could save up to $2,200 a year on a household bill, the centre’s research has claimed.
Dr Gill Armstrong, the centre’s buildings program manager, said: “They’re tried and tested. It’s low-hanging fruit, but it’s also the one area where we can move fast for households to get the benefit of lower bills.
“There’s a growing awareness that homes can be improved quite quickly. It’s a no-brainer for the federal government.”