Are heat pump hot water systems worth it in Perth?

16th May, 2023

You’ve settled on a heat pump hot water heater after doing your research on which hot water system would be best for your Perth home. You’ve heard they’re an easy replacement when upgrading your existing storage hot water system, they’re good for the environment and they’ll save you money in running costs… but as always, while scouring the net for more information, you’ve found the research out there forgets about little old Perth, focusing on the eastern states and other places. 

Fret not, Perth homeowner, as once again your friendly professionals at Ritz P&E are here to help! We’ve gathered the information and personally crunched the numbers ourselves to give you an idea on the value a heat pump hot water system can bring to your home today. 

Average running costs for a heat pump in WA 

Much like solar hot water systems use the sun to generate heat energy to warm up stored water, heat pumps take the energy from the air around us and transfers it to an insulated tank, heating the water for when you need it. While there’s a lot of numbers out there floating around on the benefits related to heat pump systems, we’ve found it hard to nail down any actual numbers. This is due to a variety of factors:

  • There is no current policy that legislates energy ratings to appear on heat pump systems.
  • Heat pump efficiency depends on the climate zone it is installed in.
  • Cost of energy is complicated by different providers and tariffs outside of WA.

We’ve decided to take it into our own hands and see just how much you’ll be saving on average when installing a heat pump hot water system into your family’s house here in Perth! It wasn’t easy, but by looking at the STCs available for the different heat pumps available on the market (which measures projected energy savings in megajoules over the next decade), comparing it to the reference hot water heater provided by the Australian Hot Water Standard  AS4234:2008 Table H9.3, and then converting this figure to the same figure that Synergy charge us per unit of electricity we use over a year (kWh/year), we can directly see the savings available for a standard household in WA. Neat! 

While other states are complicated by on-peak tariffs and different energy prices throughout the day, we’re able to take the information available and average it out across the year with no differences based on when you use the hot water. Here in Perth, we don’t have to worry about complicated timers or lining up off-peak tariffs with heating times, so we can do some straightforward calculations to get the figures in the following table. 

Average heat pump energy savings in Perth, WA compared to reference electric storage water heater:

ModelEnergy Usage
Yearly Running Costs in PerthPotential Savings
Rheem Ambiheat Heat Pump1140$34273%
Rheem Ambiheat Heat Pump with Solar PV Offset 125$3897%

How did we calculate these numbers?

Perth’s ABSB Climate Zone: Zone 3 (heat pump zone HP3-AU)
Average water usage: 40L hot water per person per day, assumed consumption for average usage is 120L for 3-person household (medium load).

Reference energy consumption (MWh/decade, medium load, climate zone 3/HP3-AU): 42.4 MWh/decade = 4240kWh/year == $1272 at 30cents/unit (Synergy’s standard residential unit rate, as of April 2023).
All simulation and reference data derived from TRNSYS software package and take into account peak usage across different seasons and times, averaging energy usage out annually for typical usage comparisons. 

Approximate energy usage calculated by taking up-to-date STC (Small-scale Technology Certificate) data from the Clean Energy Register, where 1xSTC = 1xMWh/decade of energy saved compared to reference hot water energy usage, and calculating the equivalent energy usage per year (where 1xSTC = Reference energy usage – Simulated energy usage).

Solar PV savings calculated using an average energy savings offset of 97%, reflective of Australian studies on solar PV heat pump hot water usage.

Heat pumps are also an easy option to add value and offset your heat pump hot water costs: by connecting your new heat pump to a new or existing PV electric solar system, you can reduce these costs by an average of 89% per year. With an average 1 kW PV system producing around 4.4kWh of power per day in Perth, a small system can negate your energy costs during sunlight hours easily!

Adding value to your Perth home: creating energy-efficient houses through heat pumps and PV solar

Having a heat pump hot water system won’t just save you money on ongoing energy costs – it’ll also help you add value to your home while helping you do your bit for the environment and local community. 

Once again comparing our given heat pump hot water systems to our reference electric storage water heater, we can give some numbers to the estimated greenhouse gas reductions you can get from installing a heat pump water heater at your Perth home:

BrandEnergy Usage
10-year greenhouse gas emissions
Rheem Ambiheat Heat Pump11405.4
Rheem Ambiheat Heat Pump with Solar PV Offset 1250.6

How did we calculate these numbers?

10-year greenhouse gas emissions are based on the estimated average emissions coefficient (…) over the next ten years: 0.473kg CO2-e per kWh for electricity.

Approximate greenhouse gases per decade calculated using previous energy usage calculation, converted to CO2 emissions per kWh for electricity use.

Sustainability is on everyone’s mind these days, and your house is one of the most sustainable things you can invest in as a Perth homeowner. In fact, a recent 2022 study by PropTrack, a whopping 53% of WA consumers considered energy efficiency scores extremely important when buying, building or renting! When we dig down a bit deeper, we find that 57% of Australian consumers are interested in energy efficient appliances such as heat pump hot water systems. Add a PV solar electrical system to your heat pump, and that number rises to 71% of consumers who say they’re interested in solar-enabled houses. 

It’s not just added homebuyer interest, either. Adding energy-efficient features to your home has proven to add a significant amount to your home’s value: the difference between energy-efficient homes and non-EE homes is rising year by year, according to a recent report by EE houses sold for 17.10% more than non-EE houses in 2022, compared to just 15.30% in 2019 – that’s a whopping $125,000 premium! 

What’s more, sustainable houses tend to sell a lot quicker too: EE houses tend to be on the market around 4% shorter than non-EE houses, with almost 9% more views per listing in 2022. It’s clear adding a heat pump hot water system adds significantly to your house value – and running your heat pump water heater with a PV solar electric system attracts more than just energy savings to your bills.
If you’re interested in a new heat pump hot water system for your Perth house – whether you’re replacing an old electric storage system or otherwise, the friendly team at Ritz Plumbing & Electrical are here to help. Chat to one of our friendly representatives now by calling 13 74 89 or send an enquiry using our easy online contact form.