The 5 Most Common Causes of a Very High Electricity Bill

If you have received an unusually high electricity bill you can land up feeling pretty helpless.

If you think there is something genuinely wrong with your billing you can take your complaint to the energy and water ombudsman in your state. In the vast majority of cases, however, a high electricity bill is the result of one of these five issues:

1. The electricity bill arrived around September / October.

How can the time of year that the electricity bill arrived possibly be a contributing factor!?

Let me explain. Around this time of year you get hit with two factors which can result in a skyrocketing electricity bill. This is because:

  • A bill which arrives in August to November will generally cover the highest consuming period (being June, July and August). This time of the year covers the shortest days of the year (more lighting demand), the longest and hottest showers (more hot water demand) and the most reliance on heating.
  • A bill arriving around this time is also your first bill since the electricity companies put their rates up (price rises are normally effective from 1 July of any given year). In recent years annual increases have been as high as 20% is many states.

AGL Energy Electricity Bill

2. Your previous bills have been estimated

Another fairly common cause is that your bills have been estimated for a few periods and then you get hit with the correction.

The problem starts when your utility company sends you an estimated electricity bill instead of an actual bill. This, in itself, is not a problem. Your provider is allowed to estimate your usage, but they must read your meter at least once a year.

The problem is that you may not even realise this is happening. Then, when the 'correction' bill finally arrives, it may include a catch-up amount, making it unusually high.

Be alert to this possibility and check your bills for the word ‘estimated’, or the letter ‘e’ beside the meter readings. If you keep getting estimates you can actually take a reading yourself and phone it in.

3. You have electric heating

Electric heaters might look innocent but they can consume a large amount of power very quickly. The classic example is an oil column heater used to heat a room overnight. You might think the heater doesn't use much… Until you get your next electricity bill!

For example, if you had just one 2 kW electric heater running for 10 hours per day it would consume 20 kWh (or about $5 per day in electricity).

So, despite the fact that portable electric heaters plug into normal power outlets, you should be very careful how much you use them.  If you are going to use an electric heater try using a foot mat heater like this or an electric blanket.

At least you can see a portable electric heater. Some of the worst electric heating culprits remain invisible to the user.

Examples of this include underfloor electric heating, ceiling electric heating and heated towel rails. Heating circuits like these can rack up high bills very quickly because they have a high capacity and are often left running all day. Some types of in-slab or ceiling electric heating can be left on without the occupants even noticing.

4. You have a pool

Most homes that have a swimming pool will find that it's electricity consumption is responsible for more than 30% of their energy costs.

Swimming pools use electricity in two main ways. Firstly, the filter pump is used to circulate water and run the pool cleaner. Secondly, the heating system, if present, requires additional electricity for its pumps.

Pool shops and swimming pool installers are notorious for exacerbating this problem. Despite considerable improvements to swimming pool pump efficiency over the years, they still install high capacity, over-spec filter pumps. Also, because they don't have to pay your electricity bill, they set the pump to run for 8 hours or more per day. Running a pump for this long is simply not necessary in most cases.

Additionally, many swimming pool owners think they are saving energy by having solar pool heating. Unfortunately, this is not usually the case. Although the sun is heating the water, circulation pumps are still needed to capture and use this energy.

5. You have a hot water leak (or a teenager)

Hot water is the single biggest energy user in most homes, so it's not hard to see why drastically changing your hot water consumption can have a big impact on energy bills.

If you have a leak in a hot water pipe you could inadvertently be using hot water all day. If the leak is near your hot water tank it could be weeks until you even discover the problem, let alone its impact.

On the other hand, your problem could merely be a teenager or other family member who who likes to take extra long showers...

- Ryan McCarthy

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  • Ryan ( - August 01, 2014

    Lauryn – this does sound high, but still plausible. I suggest you take your own meter reading to see if the problem has persisted since your bill arrived. We may be able to lend further assistance – please contact us if interested.

  • Lauryn Harwood - July 31, 2014

    I’ve received a bill stating a small three bedroom town house with one tenant has used 1200KwH in three weeks, one of which the house was empty? The hot water service has been checked and there is no issue there? We don’t use the heating/cooling and have one fridge?
    On average 100KwH should be used quarterly, not in two weeks. I am at a loss, any suggestions?

  • Ryan ( - January 15, 2014

    Kacl – You might need a professional Energy Audit to determine your particular issue.

    Sean – All companies I know of will accept a customer meter read with no qualms if they have not been able to take a read themselves.

  • Sean - September 27, 2013

    I’d love to know which electricity company accepts customer reads as actual reads to be applied on their bill as a correction.

  • Kacl - August 28, 2013

    Bull. We don`t use heaters in winter.The only appliance going is our fridge,washing machine on Saturdays and boiling kettle and $1000 plus bill. Don`t know who to turn to.

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Negergy (pronounced neg-er-jee) is a made up word which means 'saved energy.' We are an Australian-owned company run by Ryan McCarthy - a qualified Photovoltaics Engineer and energy efficiency specialist.

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