Does heat pump hot water save if you don’t have solar? You bet it does!
We’ve previously looked at the savings from heat pump hot water combined with solar. The results are amazing – effectively free hot water.
We installed a heat pump hot water unit in our place in Balwyn in February 2025.
But we don’t have solar, so will we still save?
I am thrilled to say that having analysed 12 months of energy bills before and after installation, I estimate our savings at $580 a year from our heat pump.
I’m delighted with the result – these types of case studies prove beyond any doubt that heat pump hot water units are the best way to heat water for your home.
Gas Bills Down 👇
I compiled all our energy bills for the last 24 months.
Below is a screenshot of our gas bills. The shaded green section shows the dates and usage attributed to our old gas hot water. This was our last gas appliance, so we know all gas usage was due to the hot water unit.
We can clearly see when the heat pump was installed – in February 2025 you can see our gas usage decreases to 0. If we calculate the usage over the previous 12 months, we can safely assume the same savings going forward.
It’s important to note that we focus on gas usage, not the gas cost on these bills. We can assume the same usage savings going forward, but the dollar savings will actually increase as gas prices increase. And you can see how they are increasing – in Feb 2024 we were paying 3.87 c per MJ, which has recently increased to 4.92 c per MJ – a 27% increase in 2 years.
The gas usage from our old hot water heater totalled 14,398 MJ.
At 4.92 c per MJ, this represents a cost of $705 per year for gas hot water.
Electricity Bills Up? 👆
The decrease in gas bills is not surprising. We’ve replaced a gas appliance with an electric appliance, so of course our gas bills are going to increase.
But what has happened to our electricity bills? Have they skyrocketed?
Below is a screenshot of the changes to our electricity bills.
The sum of the pre-installation green highlighted squares is 3,753 kWh. The sum of the post-installation blue squares is 4,190 kWh, an increase of 437 kWh. The extra usage is due to the heat pump.
Our electricity usage is not going to be the same every year, but we wouldn’t expect it to be drastically different.
At our rate of 27.3 c per kWh, this is an increase of around $120 per year.
Our gas bills have decreased $705 per year and our electricity bills have increased $120 per year, with a net saving of $585 per year.
Will you Save?
We have four people living in our house: me, my wife and our two young daughters aged 7 and 4.
I would describe our hot water usage as moderate.
My wife loves a long shower, I’m pretty quick in the shower and our girls usually have a 1/3 filled bath together each night.
We certainly don’t use as much as families with teenage kids that indulge in 15 min + showers.
If your household is likely to use more hot water, and if you have solar, you’ll save even more than us.
If your household has fewer people and uses less hot water, you may not save as much.
But given that Powrhouse’s typical heat pump installation price is around $1,500-$2,000, either way, most households will pay off their heat pump within 2-5 years.
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