Heat pump or solar pool heating: which fits your pool?
Both heat a pool well, at very different running costs and under different conditions. For most pools the answer is not either/or but both: solar collectors by day, a heat pump as backup. Here are the differences, the numbers, and when each one is enough on its own.
How each one heats a pool
They get their heat from different places, and that explains most of the differences.
A pool heat pump
Takes heat from the outside air and moves it into the water, using electricity to run a compressor and a fan. One kWh of electricity gives about 2.5–5 kWh of heat, less when the air is cold. It works at any hour, needs space with free airflow around the unit, and has moving parts.
Solar collectors
Glass vacuum tubes absorb the sun's heat and pass it straight to the water. There is no fuel and no moving parts in the panels; the running cost is only the electricity to run the system. They need daylight and a spot that gets sun most of the day, and give less on cloudy days and nothing at night.
Side by side
The practical differences, for a pool in Israel.
| Heat pump | Solar collectors | |
|---|---|---|
| Running cost per kWh of heat | About ₪0.13–0.25 | A few agorot |
| Works at night | Yes | No: the backup takes over |
| Works in winter | Yes, with less output and a higher cost per kWh in cold air | Yes, with less output on cloudy days |
| Noise | A fan and a compressor | Silent |
| Space | Free airflow around the unit, near the equipment room | A sunny roof, wall or ground frame |
| Moving parts | Compressor and fan | None in the panels |
| Installation cost | Quoted per site | Quoted per site |
Running costs at the Israel Electricity Authority household tariff from 1 July 2026 (63.52 agorot per kWh incl. VAT) and a typical heat pump COP of 2.5–5. The full cost comparison, including electric heating and gas, is in the guide on the cost of heating a pool.
When a heat pump alone is enough
A heat pump without collectors makes sense in a few cases:
There is no sunny spot
If the only free area is in shade most of the day, collectors won't pay off, and we'll say so at the survey.
The pool is used rarely and briefly
A pool heated a few times a year for short periods doesn't give the collectors enough hours to pay back.
The running cost is acceptable to you
A heat pump holds the target at any hour; you pay ₪0.13–0.25 for every kWh of heat it makes, and more in cold weather.
When solar collectors alone are enough
Collectors without a heat pump work well when the pool and the season are modest:
A small outdoor pool, swum from spring to autumn
On a 12 m³ outdoor pool we installed 3 panels and no heat pump, and the water stays stable through the season.
A cover at night
It keeps the heat the sun put in during the day, so the pool doesn't start every morning from cold.
A moderate target temperature
Every extra degree costs more heat; for winter swimming or water above 30°C a backup usually stays.
Why most pools end up with both
On days with enough sun the collectors can cover a large share of the heating; at night and on cloudy days the heat pump tops up what's missing. The controller switches it on automatically, only when the water is below your target and the sun isn't enough. So the heat pump runs fewer hours: a smaller bill, and the heat pump may last longer.
If you already have a pool heat pump, it can usually be connected to the system. What the controller can do with it — only switch it on and off, or also adjust its output — depends on the model; we check this at the site survey.
For every 1,000 kWh of heat: a heat pump costs ₪130–250 to run, solar collectors tens of shekels. The question is rarely 'solar or heat pump?' but how many hours the heat pump runs alongside the collectors.
How the hybrid system is designed for your pool: Solar pool heating
Questions about heat pumps and solar
Short answers for people choosing between the two.
Can I add solar collectors to my existing heat pump?
Usually, yes. The heat pump becomes the backup and the controller switches it on only when the sun isn't enough. What the controller can do with your model — on and off, or also adjust its output — we check at the site survey.
Is a heat pump enough in winter?
It works in winter, but in cold air it gives less heat per kWh of electricity, so each kWh of heat costs more. With a cover and collectors it runs far fewer hours; without them, winter heating is the most expensive part of the year.
Which is cheaper to run?
Solar collectors: a few agorot per kWh of heat, the electricity to run the system, against about ₪0.13–0.25 with a heat pump.
How many panels replace a heat pump?
It depends on the pool's volume, whether it's indoor or outdoor, the cover and the months you swim. A 12 m³ outdoor pool in northern Israel got 3 panels and no heat pump, for warm-season swimming; larger pools and winter swimming usually keep a heat pump as backup. Our engineers calculate the number at the site survey.
Do the collectors work on cloudy days?
With less output, yes; at night, no. That's the backup's job, and the controller switches it on automatically.