Can I run a spa pool on solar power? Common solar questions answered

Powering homes with solar energy is becoming increasingly popular. But what about using it to power a spa pool? Is it possible? Is it worth the cost? Keep reading to learn the answers.

run a spa pool with solar panel hero

Can I run a spa pool on solar power?

Yes, it's possible to run a spa pool on solar power! If it’s set up right and you have enough sunlight to power it, it could be a good option for you – saving you money on running costs while helping the environment at the same time.

There are two main ways of heating a spa pool with solar energy:

  1. Through a traditional solar panel. This consists of photovoltaic cells (or solar cells) that convert the sun's rays into usable electrical power where energy is stored in a battery that is connected to the electric circuitry.

  2. Through a heat exchanging panel. This is a solar thermal system where the spa pool’s water moves and passes through a heating system.

photovoltaic solar panels

Traditional (photovoltaic cells) solar panels

How to heat a spa pool with solar power

While there are several solar-powered spa pool heating options, as mentioned above, the most popular ones are traditional solar panels and heating exchanging panels.

Learn more about these below.

Traditional Solar Panel (Solar Electric) for heating a spa pool

To convert solar energy to usable electricity, you will need:

  • solar panels (that will collect energy from the sun)
  • a battery system for storing the power
  • a proper inverter (which will convert solar power from low voltage DC into usable electricity – which in Australia is 230V AC).

The number of solar panels required to produce enough power will vary depending on the size and type of spa pool you have.

The system will only function while the sun is out. Therefore it is advisable to purchase enough batteries for energy storage to ensure that you have enough solar power to heat up your spa on cloudy days, through the night, and in winter.

So as long as you have enough panels to harvest solar energy and sufficient battery storage, you can enjoy heated water even when the sun is not out. One of the biggest considerations for this though is the upfront investment – the price can go up the more panels and batteries you need.

Keep in mind too that electrical system expertise is necessary for a proper installation, and a trained professional should always implement this.

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Heat-Exchanging Panel (Solar Thermal) for heating a spa pool

Another way to run a spa pool on solar power is through a heat-exchanging panel. This works by getting the spa pool’s water to move and pass through a heating system.

This is a panel that has crisscrossed tiny tubes (called evacuated tube collector or ETC) where the water will pass through. ETCs retain heat collected from the sun so that when cold water passes through these tiny tubes, it gets heated before going out of the other end and into the spa.

To absorb heat, the exchanger's tubes are placed against a dark surface with a glass layer over the front to capture the heat. The sun heats the water as it travels through these tiny tubes. The water flows through the heat exchanger to the opposite side and is then pumped to the top of the hot tub.

Heat exchanging is a relatively simple and inexpensive technology. However, this requires strong sun for at least 6 hours per day in order for it to be effective.

Also, unlike traditional solar panels, this system does not have a way to store collected solar power. It will only work during the times of the day when it is hot – which is probably when you least need hot water.

The other thing you’ll need to think about with a solar thermal system is adding a pump that is powerful enough to move the water from your spa system up to wherever the heating panel is. You’ll get the best sun on the roof of your house, so you’ll need a pump that can move the water from wherever your spa is located to your roof and back.

Heat-Exchanging Panel (Solar Thermal) - Evacuated tube collector

Heat-Exchanging Panel (Solar Thermal) - Evacuated tube collector

How many solar panels are needed to run a spa pool?

The number of solar panels required depends on the size and power consumption of your spa pool. The amount of solar power you need to run a spa pool is based on its energy consumption in kWh.

Typically, you will use between four to twelve of these panels, although the exact number that you need depends on your climate and how long it takes you to warm up the water.

It is also important to know that solar systems have losses, so to ensure that you always have sufficient energy to run your spa, it is recommended that you add up to 50% of additional capacity. This will also account for when lower solar energy is harvested on cloudy days.

If your spa pool uses approximately 16 amps of power, it would require four solar panels. You will need six solar panels if your spa draws between 20 and 30 amps. If it's a larger spa pool that can accommodate up to five people and utilise over 30 amps, you need eight solar panels or more.

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Can you use a solar hot water system to heat a pool?

Yes, you can use a solar hot water system to heat a pool. It is the most environmentally-friendly method of pool heating, as well as the most cost-effective. It harnesses the natural energy from the sun to heat your pool, so it is safe and healthy for the environment and saves you a lot of money on your household bills compared to the other available methods of heating your swimming pool.

The system works through a solar pump. It pushes the pool water via a network of capillary tubes, which maintains a steady temperature throughout the pool. This run consumes a very minimal amount of electricity, often less than 1 kW per hour. Because solar energy is more dependable for longer periods of time throughout the year, sunny places are preferable for solar heating systems.

How big of a solar heating system do I need to heat a pool?

To determine how big of a solar heating system you need, you have to know first the total area of your pool. In general, a solar collector needs to cover roughly 80% to 100% of your pool's area. This is essential to achieve effective pool water heating.

spa pool in backyard

How many degrees does solar power heat a spa pool?

With just six hours of sunshine, solar-powered heaters can warm the spa pool’s water to a temperature of 100 degrees. Of course, everything is dependent on how much sun you get.

How do you plumb a spa pool with solar panels?

You need a 3-way diverter valve to connect your spa pool with solar panels through pipes. This will provide both flow rate adjustment and complete solar panel shutdown. Along with the pipe, you need directional fittings and couplings. To stop water cycling, a check valve is required right before the hot water enters the spa piping again.

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How does an evacuated tube collector for solar heat exchanging system work?

The evacuated or vacuum tube collector, also referred to as a vacuum tube solar water heater, has an array of transparent glass tubes in parallel. These tubes are connected to a header pipe. Every tube has a water pipe inside that is covered in a coating that absorbs sunlight and heats the water that runs through it. There is a vacuum between the outer tube and the water pipe that serves as an insulation property.

Their cylindrical shape efficiently helps to absorb heat even when the amount of sunlight is very low, especially during cloudy weather, early morning or late afternoon. This also makes the evacuated tube collector perfect for colder months.

How hot do solar vacuum tubes get?

The inside of solar vacuum tubes can get as hot as 150°C! However, the outer tube is cooler to touch. Why? Because of the excellent insulation properties of the vacuum. That is why the evacuated tube can function well and heat water efficiently, even in cold weather.

How much solar do I need to power the spa pool?

A spa pool can use up to 300kWh each month on average. This can be supplied by 2000 watts of solar panels and a 250Ah 24-volt battery. Consult an electrician who will calculate the number of solar panels and batteries you need to keep your spa running and heated. This will depend on your location (to determine the number of hours the sun is usually out) and the size of your solar panels and batteries.

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How to heat a spa pool with solar?

You can heat a spa pool through two types of solar heating methods. First is the ‘traditional’ solar panels with a battery system for energy storage. Another one is through a heat exchanging panel where the water passes into it.


Are solar-heated spa pools warm in winter?

It depends on how much sunlight you get, how intense the heat of the sun is, and the size of your battery bank so there is power in reserve to run your spa even during winters.

You may also consider using an Evacuated or Vacuum Tube solar heater that can heat water efficiently, even in colder weather.

How long does solar spa pool heating last?

Depending on its quality and, if properly maintained, solar water heaters have a long life and could last anywhere from 10 to 25 years.

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Is solar spa pool heating worth it?

By installing a solar spa pool heater, you could significantly cut down your heating costs. It should be a lot cheaper than your spa’s inbuilt electric heater. Depending on your setup, you may find it more cost-effective than gas or a spa heat pump. Plus, it is environmentally friendly and safe.

How much is solar heating for a spa pool?

On average, the upfront investment for a 5kW solar photovoltaic system (with 14 panels) ranges from $4,500 to $8,000. While a 10kW system (with 27 panels) can cost anywhere from $8,000 to $13,000. When pricing your solar panel installation, make sure to check if you are eligible for a discount under the Government’s solar energy rebate scheme.

solar power price

For those who find the initial investment for solar power beyond their budget, another great energy-efficient, cost-saving option is to use a heat pump. While heat pumps require electricity to operate, their energy consumption is much less than that of gas or electric

In Summary

You might want to think about using sustainable energy and saving money when it comes to your spa pool. Solar energy is also efficient even during colder months, allowing you and your family to enjoy your spa and experience the health benefits it brings even during colder months. Using solar energy is also environmentally friendly by lowering the carbon footprint.

Yes, it has many advantages. However, there are several factors you have to consider to see if it suits your needs and situation.

  • First, solar panels require direct sunlight to generate electricity. Your location should have sufficient light from the sun in order for water to be heated properly.
  • Second, there is a significant up-front cost to install the technology, but over time it will help reduce your energy costs.
  • Third, they require specialized knowledge so it is best to consult a certified electrician.

We hope all the information above guides you in deciding about considering solar energy to run your spa pool.

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