Running a Pool Heat Pump on Solar Panels
The question every customer with panels on the roof asks. Usually right after we quote them.
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Yes, a pool heat pump and solar panels work very well together, and running a heat pump off rooftop solar is the cheapest way to heat a pool in Australia. A heat pump draws most of its power in the middle of the day, which is exactly when your panels are producing. Every kilowatt hour it uses from the roof is one you would otherwise have sold back to the grid for a few cents. On a covered 40,000 litre pool, a 6.6kW solar system can carry most of the heating load on a sunny day.
There are catches. None of them are deal breakers. Here they are.
Why a pool heat pump suits rooftop solar
A pool heat pump suits rooftop solar because both do their best work at the same time of day. A heat pump pulls heat out of the air, so it is most efficient when the air is warmest, which is late morning to mid afternoon. That is also peak solar output. The two line up without you doing anything clever.
Compare that with running the heat pump overnight on grid power. Cold air, lower efficiency, full tariff. It is the worst of both.
The numbers on a real unit make the point. The Guardian Platinum 20kW inverter is rated at a COP of 16.4 to 7.5 in 27 degree air, and 7.9 to 5.3 in 15 degree air. Same machine, same pool. The warm afternoon gets you roughly double the heat per kilowatt hour compared with a cool night.
How much solar power a pool heat pump uses
A pool heat pump draws between about 0.3kW and 4kW while running, depending on its size, whether it is an inverter model and how hard it is working. Most 20kW inverter units sit around 1kW to 2kW once the pool is up to temperature. Here are the rated figures for the models we get asked about most.
Rated input power, popular pool heat pumps
| Model | Type | Rated input power | Price |
|---|---|---|---|
| Guardian Platinum 13kW | Inverter | 0.22 to 1.81 kW (max 2.5 kW) | $4,390 |
| Fairland Aqua X Essential 17.1kW | Full inverter | 0.32 to 2.51 kW (air 15 degrees) | $4,140 |
| Guardian Eco Pro 20kW | Inverter | 0.27 to 3.22 kW (max 3.8 kW) | $4,940 |
| Guardian Platinum 20kW | Inverter | 0.26 to 2.78 kW (max 3.95 kW) | $6,290 |
| SensaHeat ES 20kW | Inverter | Up to 3.26 kW | $4,700 |
| Midea M Series 20kW WiFi | On/off | Up to 5.3 kW | $3,799 |
Manufacturer rated figures from our product listings. Prices current as of September 2026, AUD including GST.
That low end is the important number. An inverter heat pump holding a warm pool can idle at a few hundred watts, which even a modest solar system covers with room to spare.
What size solar system you need to run a pool heat pump
A standard 6.6kW rooftop system is enough to run a pool heat pump on a covered family pool for most of a sunny day, alongside normal household use. You do not need a dedicated array for the pool. You need enough spare daytime generation, and most homes with a 6.6kW system export plenty of it.
Rough daily picture for a covered 40,000 litre pool held at 28 degrees in the shoulder season, with an inverter heat pump.
Heat pump daily use vs solar output
| Setup | Heat pump electricity per day | Share of a 6.6kW system's clear day output |
|---|---|---|
| Covered pool, inverter heat pump | About 8 kWh | About a third |
| Uncovered pool, inverter heat pump | About 21 kWh | Most of it, and it runs past sunset |
Assumes a 40,000 litre pool of about 32 square metres, moderate Australian shoulder season, and roughly 25 kWh from a 6.6kW system on a clear spring day. Output drops in winter and in southern states. Figures current as of September 2026.
See the problem with the second row. An uncovered pool loses so much heat overnight that the heat pump cannot catch up inside the solar window. Our pool cover guide has the full numbers, but the short version is simple: solar plus no cover mostly means grid power at night.
How much running a pool heat pump on solar saves
Running a pool heat pump on solar saves about 25 cents for every kilowatt hour it takes from the roof instead of the grid, because you pay around 30 cents to import power and give up only a few cents of feed in credit. On a covered pool using about 8 kWh a day, that works out to roughly $2 a day, $60 a month, or about $360 over a six month season.
Feed in tariffs in most states have dropped into single digit cents. That changed the maths. Exporting solar used to pay; now it barely does. Using it yourself is worth five or six times as much as selling it, and a pool heat pump is one of the easiest big loads to shift into the daytime.
Based on 30 cents per kWh import and about 5 cents per kWh feed in. Check your own retailer's rates. Figures current as of September 2026.
Inverter or on/off heat pump for solar
An inverter heat pump is the better match for solar because it can throttle down to a few hundred watts and track what the roof is producing, where an on/off unit draws its full load or nothing. On a partly cloudy day an on/off heat pump pulling 4kW to 5kW will drag power from the grid every time a cloud passes. An inverter unit sitting at 1kW mostly will not.
That does not make an on/off unit a bad buy. The Midea M Series 20kW with WiFi at $3,799 is still our best seller, and on a sunny day with a decent system it runs happily off the roof. It just leans on the grid more on marginal days. If you already have solar and plan to heat into autumn, the extra spend on an inverter pays back faster than it would without panels. Detail on why is in our inverter pool heat pumps explained guide.
How to set up a pool heat pump to run on solar
The simplest way to run a pool heat pump on solar is to set the filter pump timer to run through the middle of the day, roughly 10am to 3pm, and let the heat pump run while the water is flowing. A pool heat pump only heats when water passes through it, so the filter pump timer effectively sets the heating window.
- Move the filtration run into daylight. Plenty of pools still run the filter overnight out of habit from off peak tariffs. With solar, that habit costs money.
- Use a variable speed filter pump. A pump such as the Fairland InverPro variable speed pool pump runs long, slow cycles cheaply, which gives the heat pump more solar hours to work with.
- Cover the pool at night. The heat you bank during the day on free power has to survive until morning.
- Use the WiFi app if the unit has one. Scheduling and a set temperature from your phone make it easy to shift heating into daylight.
- Ask your solar installer about load control. Some solar inverters and smart relays can switch a load on when the system is exporting. Whether that suits your setup is a question for them and your electrician.
Can a pool heat pump run directly off solar panels with no grid?
No, the pool heat pumps we sell are standard 230V appliances and cannot be wired straight to solar panels. They run on mains power from your switchboard, and the solar system feeds that switchboard like it feeds everything else in the house. The heat pump does not know or care where its power comes from.
A fully off grid pool heat pump would need a large battery and inverter system sized for a 2kW to 5kW continuous load. It can be done. It rarely makes sense for a backyard pool.
Batteries follow the same logic. Draining a home battery into the pool is usually a poor use of stored power that you would rather have for the evening peak. Run the heat pump off live solar during the day and keep the battery for the house.
Solar panels vs solar pool heating
Solar panels running a heat pump and solar pool heating are two different things: solar pool heating pumps water through collectors on the roof, while solar panels make electricity that runs a heat pump. Rooftop collectors heat water directly and cost almost nothing to run, but they need a lot of roof, they struggle in cool weather and they cannot add heat on a cloudy week. A heat pump on solar PV keeps working in the shoulder season and gives you a set temperature.
If you already have panels, a heat pump uses them. If you have neither, our solar vs heat pump pool heating comparison goes through which one fits your roof and climate.
Which heat pump we recommend for a solar home
For a solar home with a standard 30,000 to 40,000 litre pool, we recommend a 17kW to 20kW inverter heat pump such as the Fairland Aqua X Essential 17.1kW at $4,140 or the Guardian Eco Pro 20kW at $4,940. Both throttle down low enough to sit comfortably under a 6.6kW system's output.
Smaller pools and plunge pools suit the Guardian Platinum 13kW, which draws as little as 0.22kW once warm. If the budget is tight, the Midea 20kW still works on solar, with the caveats above. More on that unit on the Midea 20kW page.
Prices current as of September 2026, AUD including GST.
The full range from 9kW to 35kW sits in Heat Pumps for Pools & Spas.
Frequently asked questions
Can you run a pool heat pump on solar panels in Australia?
Yes. A pool heat pump runs from your switchboard like any other appliance, so a rooftop solar system powers it whenever the panels are producing. Running the heat pump between about 10am and 3pm lets most homes with a 6.6kW system cover the bulk of the heating load from the roof on a sunny day.
How many solar panels do you need to run a pool heat pump?
A standard 6.6kW rooftop solar system is usually enough to run an inverter pool heat pump on a covered family pool through a sunny day. A covered 40,000 litre pool needs about 8 kWh of heat pump electricity a day in the shoulder season, roughly a third of that system's clear day output.
How much does solar save on pool heat pump running costs?
Solar saves about 25 cents for every kilowatt hour the heat pump takes from the roof instead of the grid, based on 30 cents import and about 5 cents feed in. On a covered pool that is roughly $60 a month, or about $360 over a six month season.
Is an inverter pool heat pump better with solar?
Yes. An inverter pool heat pump can throttle down to a few hundred watts and follow the solar output, while an on/off unit draws its full 4kW to 5kW load or nothing, which pulls grid power whenever a cloud passes. An on/off unit still works on solar, just less efficiently on marginal days.
Can a pool heat pump run off grid on solar only?
Not directly. Pool heat pumps are standard 230V appliances that run from mains power, so an off grid setup would need a large battery and inverter sized for a continuous 2kW to 5kW load. For almost every backyard pool it is far cheaper to run the heat pump on live daytime solar with the grid as backup.
What time of day should I run my pool heat pump with solar?
Run a pool heat pump with solar between about 10am and 3pm, when panel output and air temperature both peak. Warm air gives the heat pump a higher COP, and peak solar means the power is close to free, so midday heating costs a fraction of overnight heating on grid power.
Got solar and a pool? Ask us
Tell us your pool volume, your postcode, your solar system size and whether the pool is covered. We will tell you which heat pump sits comfortably under your solar output and what it should cost to run.
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This guide is general information for Australian pool owners and is not advice on your specific pool, site, solar system or electricity plan. Running costs and savings are illustrative figures based on stated assumptions, not a quote. Pool heat pumps are electrical appliances and must be connected by a licensed electrician. Any changes to solar, battery or load control equipment should be made by your solar installer or a licensed electrician. Confirm final sizing with us or your pool professional before you buy.