Solar vs Heat Pump Pool Heating: Which Wins in Australia
Solar vs heat pump pool heating, compared honestly by people who sell one of them and get asked about the other every week.
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Solar wins on running cost, a heat pump wins on control. Solar pool heating is close to free to run but only heats when the sun is on your roof, and you cannot set a temperature. A heat pump costs a few dollars a day in use, and in exchange you dial in 28 degrees and it holds 28 degrees, day, night, cloud or shine. Most Australian pool owners who swim regularly end up with a heat pump. Summer swimmers in a warm climate with a big north facing roof do very well out of solar.
The short version, in one table
Solar is cheaper to run and a heat pump is more reliable. That trade is the whole decision, and here is how it plays out.
| Solar pool heating | Pool heat pump | |
|---|---|---|
| Running cost | Almost nothing, just extra pump time | Low, but real. A few dollars a day in use |
| Set a temperature | No. You get what the sun gives you | Yes. Thermostat holds your set point |
| Works at night or under cloud | No | Yes |
| Typical season | Summer plus a few shoulder weeks | Spring through autumn, winter in warm states |
| Needs | Large unshaded roof, ideally north facing | Power, airflow, about a square metre of slab |
| Upfront cost | Roughly $3,000 to $7,000 installed | $2,690 to $9,451 for the unit, plus install |
| Best for | Warm climates, summer swimmers, big roofs | Anyone who wants a set temperature on demand |
General guide for Australian pools. Waternex heat pump prices current as of July 2026, AUD including GST. Solar figures are typical installed market ranges and vary hard by roof and installer.
Solar pool heating: nearly free to run, but the sun decides
Solar pool heating pushes your pool water through black polymer strip collectors on the roof, where the sun warms it, then returns it to the pool. No fuel, no compressor. The only energy it uses is extra run time on your pool pump, which is why the running cost is close to nothing. A controller sends water to the roof only when the roof is hotter than the pool.
On a clear Australian summer day it works beautifully. A well sized system holds a pool several degrees above where it would sit unheated and stretches the swimming season by a few weeks at each end. Free warmth off a roof you already own is hard to argue with. The limits are the honest part: solar pool heating cannot heat at night, does very little under heavy cloud, and is close to useless in a southern winter. You do not set a temperature, you accept one. A run of grey days in October and the pool goes cold, and there is nothing to do but wait for the sun.
Roof space is what rules solar in or out
Solar pool heating needs collector area equal to roughly 80 to 100 percent of your pool surface area, unshaded, pointed somewhere near north. An 8m by 4m pool is 32 square metres of water, so you need something like 26 to 32 square metres of clear roof, and it has to be the right roof.
Plenty of houses do not have it. A south facing roof, a neighbour's gum tree, a courtyard block with barely any roof at all. If the roof does not suit, solar is off the table no matter how good the running cost looks. A heat pump needs about a square metre of ground near the pool equipment and clear airflow around it, which almost every property can find.
Heat pump pool heating: you set 28 degrees and you get 28 degrees
A pool heat pump holds your pool at a temperature you choose, regardless of sunshine. It pulls warmth out of the outside air with a refrigerant circuit and a compressor and moves it into the water, so it works at 9pm in July the same way it works at noon in January. Set the thermostat, walk away, swim when you like. That is why heat pumps outsell every other pool heater we stock.
Efficiency is the other half of it. A heat pump does not make heat, it moves it, so for every 1 unit of electricity it draws a good one delivers 5 or more units of heat into the water. That ratio is the COP, and it makes a heat pump roughly five times cheaper to run than an electric element and comfortably cheaper than gas. Full comparison in our post on gas versus electric versus heat pump pool heating. An inverter model cuts the cost again by throttling the compressor down to a low hum once the water is at temperature instead of switching hard on and off, which is why we point people at the Guardian Platinum 20kW inverter or the Guardian Lux-V 17kW full DC inverter when running cost is the priority.
What a heat pump will not do is defy physics. It takes heat from the air, so on a cold morning it works harder and delivers less, and deep winter in Hobart or Canberra is a real ask. Sized for the climate it lives in, that is a non issue for most of the country.
Running cost, put in real terms
Solar costs a few cents a day and a heat pump costs a few dollars a day on a typical family pool. Solar only draws the extra pool pump power needed to push water to the roof. A heat pump draws real power while it is heating, then much less while it is holding temperature, especially an inverter with a cover on the pool.
The comparison is not quite apples to apples, and this is the bit people miss. Solar is cheap because it does less: it warms the pool when the weather is already good. A heat pump is delivering heat on the cold cloudy evening when solar has given up, and that heat has to come from somewhere. You are paying for availability, not for inefficiency. Our breakdown of the cheapest way to heat a pool runs the numbers on both. One thing lowers the bill on either system more than anything else you can buy: a pool cover. An uncovered pool loses most of its heat overnight through evaporation off the surface, so spend on a cover before you spend on extra kilowatts or extra collector area.
Season length, which is the real difference
Solar adds a few weeks to each end of summer, a heat pump adds months. Solar pool heating is at its best from roughly November to March across most of the country, with useful warmth in October and April on the good days. A properly sized heat pump holds a swimmable pool from September through May in Perth, Brisbane, Sydney and Adelaide, and pushes into winter in the warmer half of the country.
Decide how long a season you want before you compare anything else. If you swim in summer and are happy for the pool to be a bit warmer rather than a set temperature, solar is excellent value. If you want a pool you can rely on in September, or for a birthday party in April, that is a heat pump. Sizing for the longer season is covered in our pool heat pump sizing guide.
The setup that beats both: a heat pump on your own solar panels
Running a heat pump off rooftop solar PV gives you solar economics with heat pump control. A heat pump is an electrical appliance, so if you have panels and you run it through the middle of the day, most of the electricity it uses is electricity you generated. Run it in the solar window rather than overnight, put a cover on to hold the heat until evening, and the quarterly bill barely moves. Worth pricing before you commit 30 square metres of roof to water collectors. Some pool owners run collectors and a heat pump together so solar does the free work and the heat pump fills the gaps, which is a sensible upgrade if existing collectors are not keeping up.
So which one wins?
A heat pump wins for most Australian pool owners, and solar wins in specific circumstances. Buy a heat pump if you want to set a temperature, swim across a long season, swim at night, or your roof does not suit collectors. Buy solar if you live somewhere warm, swim in summer, have a large unshaded north facing roof, and are happy to take the temperature the weather gives you. Buy a heat pump and run it on your own PV if you want both.
We stock pool heat pumps from 9kW to 35kW, covering everything from a plunge pool to a lap pool. The Guardian Eco Pro 9kW handles plunge pools and spas, the SensaHeat ES 16kW suits small to mid family pools, and our best seller by a wide margin is the Midea M Series 20kW with WiFi, the size most standard family pools land on. More detail on that one in our Midea 20kW guide. At the top end the Guardian Eco Pro 35kW covers the biggest backyard pools. See the lot in Heat Pumps for Pools & Spas or the wider Heat Pumps collection. Both systems lean on your pool pump, and an old single speed unit can cost more to run than the heater, so a variable speed pump from our swimming pool pumps range is often the quiet win on a pool heating project.
Prices and models current as of July 2026, AUD including GST.
Frequently asked questions
Is solar pool heating better than a heat pump in Australia?
Solar pool heating is better on running cost and a heat pump is better on control and season length. Solar costs almost nothing to run but only heats when the sun is on the roof and cannot be set to a temperature. A heat pump costs a few dollars a day and holds whatever temperature you set, day or night. Most Australian pool owners who swim regularly choose a heat pump.
Is solar pool heating worth it?
Solar pool heating is worth it if you live in a warm part of Australia, swim mainly in summer, and have a large unshaded roof facing somewhere near north. It lifts the pool several degrees and adds a few weeks to each end of the season for almost no running cost. It is not worth it if your roof is small, shaded or south facing, or if you want a set temperature you can rely on.
How much roof space does solar pool heating need?
Solar pool heating needs collector area of roughly 80 to 100 percent of the pool surface area. An 8m by 4m pool has 32 square metres of surface, so it needs around 26 to 32 square metres of clear, unshaded roof, facing somewhere near north. Houses that cannot supply that area usually go with a heat pump instead.
Can you run a pool heat pump on solar panels?
Yes, and it is one of the best setups going. A pool heat pump is an electrical appliance, so running it through the middle of the day on rooftop solar PV means most of the power it uses is power you generated. You keep the thermostat and set temperature of a heat pump while cutting the running cost close to solar levels. Add a pool cover to hold the heat into the evening.
Does solar pool heating work in winter in Australia?
Solar pool heating does very little in winter across most of Australia. The sun is low, the days are short, and the roof rarely gets warm enough to add useful heat to the water. In the tropics it keeps contributing year round, but in Melbourne, Hobart, Canberra and Adelaide a solar heated pool is effectively unheated through winter. A correctly sized heat pump keeps working in the cold months.
Not sure which way to go? Ask us
Tell us your pool volume, your postcode, whether the pool is covered and how long a season you want, and we will tell you whether a heat pump makes sense and exactly which model fits. If solar suits your roof better, we will say so.
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This guide is general information for Australian pool owners and is not a substitute for advice on your specific pool, roof and site. Pool heat pumps are electrical appliances and must be connected by a licensed electrician. Solar pool heating involves roof work and pool plumbing and should be installed by a licensed installer. Confirm the right system and size with us or your pool professional before you buy.