If you've just opened your electricity bill and felt a wave of shock, you're not alone. Millions of Australians experience bill shock every quarter. The good news is that most high bills have identifiable causes — and most of those causes have practical fixes. Here are the 10 most common reasons your electricity bill is higher than expected, along with what you can do about each one.
1. Old or Inefficient Hot Water System
Hot water heating is typically the largest single energy consumer in an Australian home, accounting for 20–30% of total electricity use. If you have an old electric resistance hot water system (the big tank in your laundry or outside), it's using 3–4 times more electricity than a modern heat pump alternative.
Fix: Replace with a heat pump hot water system. After rebates, a quality heat pump costs $1,500–$2,500 installed and saves $500–$800 per year. Payback is typically 2–4 years.
2. Inefficient Heating and Cooling
Heating and cooling account for around 20–40% of household energy use. Running an old, undersized, or poorly maintained system costs significantly more than it should. Setting your thermostat just 1°C lower in winter or higher in summer can save 5–10% on heating/cooling costs.
Fix: Service your air conditioner annually, clean filters monthly during heavy use, and set your thermostat to 24°C in summer and 20°C in winter. Upgrading to a modern reverse cycle unit with a high energy rating can halve your heating and cooling costs.
3. Pool Pump Running Too Long
A standard single-speed pool pump draws 1–2kW and many Australians run theirs for 8–12 hours a day. That's 8–24 kWh daily — potentially $2–$8 per day depending on your rate. Most residential pools only need 4–6 hours of filtration.
Fix: Reduce run time to 6 hours in summer and 4 hours in winter. Better yet, upgrade to a variable speed pump that uses 70–80% less energy. A timer ensures the pump only runs during off-peak or solar generation hours, saving $300–$800 per year.
4. Old Fridge or Freezer
A fridge from the early 2000s can use 500–700 kWh per year, while a modern 4+ star fridge uses just 250–350 kWh. If you're running a second fridge or bar fridge in the garage, that's another 300–600 kWh per year — often cooling very little.
Fix: Upgrade to a 4+ star rated fridge and consider whether you really need that second fridge. Switching off an unnecessary bar fridge saves $100–$200 per year.
5. Clothes Dryer Overuse
A conventional electric clothes dryer uses 3–5 kWh per load. Running it 4–5 times per week adds up to $200–$400 per year. Australia's climate means most households can air-dry clothes outdoors for the majority of the year.
Fix: Use a clothesline or indoor drying rack whenever possible. If you do need a dryer, consider a heat pump dryer which uses 50–60% less energy than a conventional model.
6. Standby Power and Phantom Loads
Devices left on standby — TVs, gaming consoles, chargers, set-top boxes, computer monitors — collectively draw 50–100 watts 24/7 in a typical home. That's 440–880 kWh per year, costing $130–$350 annually for doing absolutely nothing. Our guide to the true cost of phantom load in Australian homes shows which devices are the worst offenders.
Fix: Use smart power boards that cut standby power when devices are off. Focus on entertainment systems and home offices where multiple devices cluster together.
7. Wrong Rate Plan
Many Australians are on an electricity plan that doesn't suit their usage patterns. You might be on a time-of-use tariff while using most of your power during peak hours, or on an expensive default plan because you never switched from the one your retailer assigned you.
Fix: Compare plans using the government's Energy Made Easy website (or Victorian Energy Compare in VIC). Switching to a better-suited plan can save $200–$500 per year with zero changes to your behaviour.
8. Poor Insulation
Many Australian homes, particularly those built before 2005, have inadequate insulation — or no ceiling insulation at all. Without insulation, up to 35% of winter heating escapes through the ceiling, and summer heat pours in, forcing your air conditioner to work much harder.
Fix: Install or upgrade ceiling insulation. It costs $1,500–$3,000 for a typical home and can reduce heating and cooling costs by 20–30%, saving $200–$600 per year. Wall insulation and draught sealing deliver additional savings.
9. Using an Electric Oven or Portable Heaters for Space Heating
Portable electric heaters (fan heaters, bar radiators, oil column heaters) are some of the most expensive ways to heat your home, drawing 2–2.4kW continuously. Running one for 6 hours a day costs $3–$5 per day. Some people even use their kitchen oven for heating — incredibly dangerous and expensive.
Fix: A reverse cycle air conditioner produces 3–5 times as much heat per kilowatt of electricity consumed, making it 3–5 times cheaper to run. Even a small split system for one room is dramatically more efficient than a portable heater.
10. Estimated Bill Reads
If you don't have a smart meter, your bill may be based on an estimated read rather than your actual usage. Estimated bills use historical data or averages and can be wildly inaccurate — sometimes overcharging you by hundreds of dollars.
Fix: Check your bill for an "E" next to the meter reading, indicating an estimate. Submit your own meter reading to your retailer (most accept photos via their app), or request a smart meter installation. In Victoria, smart meters are already standard. Other states are rolling them out progressively.
What to Do Next
Start by identifying which of these issues apply to your home. Use our Bill Analyser tool to break down your current costs and see exactly where your money is going. Then prioritise fixes based on the savings-to-cost ratio — often, the cheapest changes deliver the biggest returns.