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Wasted Energy Report
How much energy are Aussies wasting each year, and how much is it costing?
By analysing national data on household energy use, price and emissions, the energy comparison service iSelect has modelled how much energy could realistically be avoided across everyday activities like heating and cooling, cooking, hot water, lighting and appliance use.
Because real household energy use varies, conservative low, medium, and high scenarios were applied to reflect typical behavioural waste, such as unnecessary use, inefficient temperature settings, and standby power. Electricity waste was calculated across all households, while gas waste was modelled separately for homes connected to gas networks. This means national totals reflect electricity waste across all households, plus gas waste only in gas-connected households.
The results show the potential impact per household, by state, and nationwide, giving Australians a clearer picture of the real cost of everyday energy habits. Let’s dive in!
Australia’s avoidable household energy waste: cost and emissions
Our modelling shows Aussie households could be wasting between $1.31 billion and $4.21 billion every year on avoidable electricity and gas costs. For the average Australian household, that’s around $131 to $422 in unnecessary energy spend per year.
The environmental impact is just as significant. Avoidable household energy waste is estimated to produce 2.27 to 7.25 million tonnes of CO₂-e nationally each year, accounting for roughly 0.5% to 1.6% of Australia’s annual net greenhouse gas emissions. In the mid scenario, that’s equivalent to removing the tailpipe emissions from almost 2.1 million passenger cars from roads.
On a per-household basis, that’s approximately 227.4 kg of avoidable CO₂-e emissions annually in a low-set environment, rising to 725.0 kg in higher-use scenarios. The mid-level national average household energy waste (439.4 kg CO₂-e) is roughly equivalent to 2,300km driven in a light vehicle, roughly the distance from Sydney to Cairns, and it would take roughly 17.6 growing trees absorbing carbon for a year to offset the average household’s avoidable energy waste.
The habits that waste the most energy
Nationally, households waste between 311.1 and 973.9 kWh of electricity per year through avoidable consumption. The largest driver of this waste is everyday appliance habits. Appliances account for 45.9% of total household electricity consumption, and even with conservative waste assumptions of 5% to 15%, they produce the greatest absolute electricity losses.
In the mid-range electricity usage scenario, the average Australian household wastes $72.05 per year from appliance-related electricity behaviour. Because appliances are used daily in every home, small behavioural changes, such as switching off unused devices and reducing unnecessary runtime, can have a significant nationwide impact.
Space heating and cooling is the next major contributor, representing 20.8% of national electricity use. However, in colder states like the ACT and Tasmania, space conditioning makes up as much as 34% to 38% of electricity consumption. Waste assumptions are higher than those for appliances, ranging from 8% to 25%, as thermostat settings and unnecessary heating or cooling periods can substantially increase waste, especially in colder climates.
For gas-connected households, space heating overwhelmingly drives avoidable waste. Space conditioning accounts for 61.1% of national gas use, with waste assumptions of 6% to 20%. Overall, space conditioning costs the average Aussie household around $58.49 in wasted electricity and $47.12 in wasted gas per year.
Lighting (8.3% of electricity use) and cooking (7.5%) make up smaller shares of household electricity consumption. While lighting has relatively high waste potential (6-16%), its lower overall usage limits total wastage. Cooking is one of the smallest contributors, even under higher waste scenarios, likely because most cooking equipment is only used when actively attended.
Wasted energy costs per household
The typical Australian household wastes $2.52 to $8.09 per week on avoidable energy use. At the national level, average mid-level waste is roughly equivalent to a week of groceries or an annual Netflix subscription, while high-level waste is close to a typical quarterly electricity bill, showing just how much Aussies could save by cutting unnecessary energy use.
In high-energy-use states like Victoria and the ACT, households with higher energy waste could be wasting around $9.91 and $11.84 per week, respectively, adding up to more than $500 per year. In Victoria, relatively low electricity prices help offset costs, but reliance on gas and high energy use for space heating in colder temperatures still drives significant waste.
In the ACT, cold winters coupled with a high proportion of gas-fuelled households mean space and water heating quickly add up when taking longer showers or heating homes to higher-than-needed temperatures.
On the other hand, Queensland records the lowest weekly cost of avoidable energy waste at just over $6 per week. This is largely driven by its warmer climate and low gas penetration, meaning households typically use less energy for space heating and hot water compared to colder states, reducing the overall opportunity for high-cost energy waste.
Cutting avoidable energy waste doesn’t have to be complicated. Simple habits like turning off appliances when they’re not in use, unplugging chargers, turning lights off when not needed and using efficient settings can make a real difference. Adjusting your thermostat just a few degrees higher in summer or lower in winter can reduce unnecessary heating and cooling costs without compromising comfort. Efficient cooking habits, such as using lids on pots, matching pan size to the burner, and running full loads in dishwashers or washing machines, can save both energy and time. Even small changes in shower times or lowering water temperatures can add up. Together, these everyday choices can significantly reduce your energy bills and help the environment.
Another way Aussies can cut costs is by comparing energy providers to ensure they’re on a competitive rate. At iSelect, we help Australians compare plans from a range of providers to look for one that suits their lifestyle and budget.
Julia Paszka
General Manager – Utilities & Credit Cards at iSelect
About the data
Electricity Consumption Baseline Method
State-level household electricity consumption baselines were primarily derived using Australian Energy Regulator (AER) residential consumption benchmarks, weighted by distribution network household sample counts.
For jurisdictions where AER benchmarks were not available (Western Australia and Northern Territory), baseline electricity consumption was derived using Residential Baseline Study (RBS) modelled state electricity consumption totals. These values were converted from petajoules (PJ) to kilowatt-hours (kWh) using a conversion factor of 1 PJ = 277,777,778 kWh.
Per-household electricity consumption was then calculated by dividing state electricity totals by ABS household counts.
RBS-derived state baselines were compared against AER benchmark states to ensure consistency between modelling frameworks. Minor discrepancies between summed end uses and reported totals reflect rounding in published tables. For modelling, end-use totals were summed and shares normalised.
National household electricity consumption baselines were calculated using a household-weighted average across all states and territories.
Avoidable/Wasted Energy – Electricity
Wasted energy for the purposes of this research is limited to energy that could realistically be reduced through behavioural change, operational optimisation, or low cost efficiency improvements that do not require major home upgrades, structural modifications, or full appliance system replacement. This includes:
- Behavioural changes
- Turning things off
- Shorter runtime
- Not conditioning empty rooms
- Lower hot water usage
- Better thermostat habits
- Low Effort / Low Cost Actions
- Turning standby / idle off
- Eco modes
- Timer usage
- Basic maintenance
- Basic upgrades/replacements e.g. LED bulb replacement
- Operational Optimisation
- Optimised temperature settings
- Running appliances at optimal times
- Reducing unnecessary usage
Waste percentages were informed by Australian Government energy behaviour guidance (e.g. thermostat optimisation guidance indicating 5–10% energy reduction per degree adjustment), standby power research estimating 3–10% of household electricity use attributable to idle loads, behavioural field trials demonstrating 5–15% reductions from feedback and optimisation programs, and appliance runtime optimisation studies. Conservative ranges were applied to reflect realistically achievable behavioural reductions rather than total technical efficiency potential.
Ranges were designed to represent:
- Low – Easily achievable behaviour changes only
- Mid – Realistic improvements for typical households
- High – Strong behaviour optimisation without major capital upgrades
Waste energy percentages were applied only to end-use energy consumption, not to total household energy bills.
Electricity
| End Use | Low | Mid | High | Behavioural Rationale |
| Appliances | 5% | 9% | 15% | Standby loads, idle electronics, unnecessary runtime, unused secondary appliances |
| Cooking | 2% | 4% | 8% | Avoidable preheating, inefficient burner/oven use, excessive runtime |
| Lighting | 6% | 10% | 16% | Lights left on, inefficient bulbs, excessive brightness and over-lighting |
| Space Conditioning | 8% | 16% | 25% | Overheating/overcooling, conditioning empty rooms, poor thermostat behaviour |
| Water Heating | 5% | 11% | 18% | Excess hot water use, elevated temperature settings, unnecessary cycles |
Gas
| End Use | Low | Mid | High | Behavioural Rationale |
| Appliances | 3% | 6% | 12% | Pilot lights, unnecessary runtime of gas appliances |
| Cooking | 2% | 4% | 7% | Inefficient burner use, long cooking duration |
| Space Heating | 6% | 12% | 20% | Overheating, heating empty rooms, thermostat misuse |
| Water Heating | 5% | 10% | 18% | Long showers, elevated tank temperatures, avoidable hot water cycles |
Some household appliance electricity consumption represents essential background system load (such as refrigeration and modem/routers) and is not considered waste. Waste percentages therefore apply only to discretionary and behaviour-driven appliance usage.
These estimates represent indicative modelling outcomes rather than directly measured household waste. Actual household energy savings will vary depending on dwelling characteristics, climate, technology mix, and occupant behaviour. The analysis is intended to illustrate the scale of potentially avoidable energy use under realistic behavioural and operational improvement scenarios.
Wasted household electricity consumption was calculated by applying behaviourally achievable waste ranges to each major end-use category (appliances, cooking, lighting, space conditioning, and water heating). These waste rates were then weighted using each state’s electricity end-use profile from the RBS, producing a state-specific avoidable energy estimate per household.
This model estimates avoidable waste within household electricity consumption only. Some end uses (particularly space conditioning, water heating and cooking) may be supplied by gas in a subset of homes, depending on location and appliance mix. For this reason, results should be interpreted as avoidable waste within electricity consumption, and total household energy waste may be higher when gas and other fuels are included.
Avoidable/Wasted Energy – Gas
Gas avoidable waste was modelled using Residential Baseline Study end-use categories (appliances, space heating, water heating and cooking). End-use shares from RBS were used to allocate each state’s average household gas consumption across these categories, and avoidable waste ranges were applied at the end-use level to estimate realistically achievable behavioural reductions. Unlike electricity, gas has limited “background” consumption, so avoidable waste is primarily driven by runtime and usage behaviour rather than standby loads or technical efficiency upgrades. Ranges are conservative and exclude appliance replacement, electrification, insulation upgrades, or building fabric improvements.
Electricity Tariffs and Cost Impact ($)
The modelling estimates avoidable electricity consumption behaviour and was valued using state electricity usage tariffs ($/kWh). The state electricity usage tariff prices are based on the average of the cheapest residential market offer usage rate from the top 3 retailers by market share in each state (NT and WA use the maximum rates for residential customers set by state regulators). The prices are based on capital city residential properties with medium-level usage from single rate electricity plans with no controlled load, no demand charges and with no conditions, discounts or offers.
National electricity pricing was calculated using a household weighted average of state retail usage charges to reflect the distribution of Australian households. Prices are correct as of February 2026.
Costs were calculated per household (daily, monthly, annual) and multiplied by state household counts to estimate state totals. The national tariff was calculated as a household-weighted average of state tariffs.
Emissions (CO₂-e)
Avoidable electricity (kWh) was converted to emissions using National Greenhouse Accounts (NGA) Factors 2025 Scope 2 location-based electricity emission factors (kg CO₂-e/kWh). Where multiple electricity grid emission factors exist within a state, the factor representing the primary residential population grid was applied. For example, Western Australia modelling uses the South West Interconnected System (SWIS) factor as it represents the majority of residential electricity consumption. Emissions were reported per household (daily/monthly in kg; annual in tonnes) and as state totals (tonnes), and summed to a national total.
For gas emission factors, direct combustion emissions (Scope 1) were applied nationally using the pipeline natural gas combined gases factor. Indirect upstream emissions (Scope 3) were applied using state metro factors. Where state values were confidential (Tasmania and Northern Territory), NGA guidance was followed using Victorian and Western Australian proxy values respectively.
The national natural gas emission factor was calculated using a household-weighted average of state Scope 1 and Scope 3 emission factors from the National Greenhouse Accounts Factors 2025, weighted using ABS household distribution data.
Note that the ACT electricity emissions are modelled using NGA Factors 2025 Scope 2 location-based emission factors, which reflect physical grid generation intensity rather than the ACT Government’s renewable energy procurement arrangements.
Household Gas Penetration
Gas household penetration was derived using Energy Networks Australia residential connection counts as the numerator and ABS occupied household counts as the denominator. Using ABS households as the denominator ensures consistency with electricity consumption modelling and allows direct comparability of per-household outcomes across energy types.
Assumptions and Limitations
This analysis estimates avoidable electricity consumption and associated cost and emissions impacts using national benchmark consumption data, regulatory emissions factors and representative retail electricity tariffs. The modelling is designed to reflect realistic, behaviour-driven reductions that could be achieved without major home upgrades, equipment replacement, or structural changes. The results should therefore be interpreted as indicative of typical household behaviour patterns rather than precise predictions for individual households.
While the benchmarks used in the study implicitly include households with rooftop solar and other distributed energy resources, the model does not separately simulate solar export behaviour, feed-in tariff offsets, battery storage or time-of-use optimisation. Avoidable electricity is valued using retail usage tariffs as a proxy for economic cost, meaning actual bill impacts for individual households may differ depending on tariff structure, solar generation, usage timing, and retailer pricing conditions.
Avoidable energy percentages are estimates that represent realistically achievable behaviour-driven reductions such as reducing standby power, unnecessary lighting, inefficient thermostat settings and avoidable appliance runtime. They do not represent total technical efficiency potential or retrofit savings that may be achieved through appliance replacement, insulation upgrades or structural improvements.
Actual household electricity use, costs and emissions will vary based on dwelling characteristics, climate, occupancy patterns, appliance mix, tariff structure and individual behaviour. Results are intended to illustrate the scale of avoidable electricity use at a population level rather than predict outcomes for any specific household.
Gas Tariffs and Cost Impact
Residential gas tariff assumptions were based on publicly available retail market pricing and regulated tariff schedules as of February, 2026. For eastern and southern states with competitive retail gas markets (NSW, VIC, QLD, SA, ACT, TAS), usage charges were estimated using an average of the cheapest available residential market offer usage rates from the largest retailers by market share in each state. The prices are based on residential properties with medium-level usage from single rate plans with no demand charges and with no conditions, discounts or offers.
For Western Australia, where residential gas pricing is regulated, the maximum standard contract usage rate published by the Western Australian Government for the Mid-West/South-West distribution zone was used as the benchmark. This region was selected as it represents the majority of residential gas connections in the state and provides the most representative pricing for population-weighted modelling.
Due to the absence of a widespread residential natural gas network in the Northern Territory, and the reliance on bottled LPG for household gas needs, NT has been excluded from the natural gas consumption model. This decision reflects the unique energy infrastructure and consumption patterns within the territory.
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