Heating swimming pools are expensive. According to recent research, it costs U.S. consumers billions of dollars annually to heat the nation’s 5.7 million swimming pools. Homeowners spend between $1,200 and $5,000 on standard pool maintenance annually.
Pool solar panels can help to heat your swimming pool and shave a good amount off energy bills as they have low annual operating costs. Furthermore, solar heaters are more cost competitive compared to gas and heat pump pool heaters.
As with any solar purchase, you should first take into account certain factors associated with your swimming pool. There are a few types of solar heaters for different kinds of swimming pools.
What is a solar pool heater?
A solar pool heater is essentially a pool heater that uses solar power and solar installation as heating mechanisms. The main difference between solar pool heaters and other conventional pool heaters is that the former only works when the sun is out.
Most solar pool heating systems include the following:
- Solar collector: heats the pool water
- Filter: removes debris before the water enters the solar collector
- Pump: circulates water through the filter and solar collector then back to the pool
- Flow control valves: divert pool water through the solar collector
- Automated sensors: detect the temperature of the water coming from the solar collectors compared to the desired temperature and controls the valves
The solar collector can be placed on a rooftop or beside the swimming pool. The device consists of photovoltaic solar panels, much like a regular solar system, but the pv panels are designed to absorb the heat from the sun instead of converting sunlight into electricity. The panels are layered over tubes where swimming pool water is pumped through.
How do solar pool heaters work?
- The pump draws water from the swimming pool into a filter to remove dirt and debris. Some systems have an additional strainer.
- A filtered pool is directed through a series of valves to solar collectors.
- Water enters solar collectors on one end of individual tubes.
- Heat and radiant energy warm up the water in the solar collectors.
- The heated water exits the other end of the tubes in solar collectors.
- Sensors detect the temperature of the water.
- If there is an existing conventional pool heater, the heated water passes through this before entering the pool.
- The cycle is repeated until the pool water reaches the desired temperature. If the swimming pool is already hot, the control valves ensure that additional hot water doesn’t enter the pool.
The entire process is seamless once it has been installed.
Are solar pool heaters worth it?
Yes, once you compare the total installation cost of a solar pool heater with the cost of conventional heating. The return of investment for a solar pool heater can be earned back within a few years. This is assuming you use it consistently for the same period of time as a conventional heater.
How much does solar pool heating cost?
For a standard-sized swimming pool, a gas heat pump can cost above $1,500 per year. An electric heat pump averages at half this cost. The heating bill exists every time you use the heater.
However, a solar pool heater costs almost nothing to use and maintain. You do not need any electricity to keep the solar heating system running. It can therefore pay for its initial installation cost within a few years.
The savings will add up where subsidies or tax breaks are given for solar in some states. Furthermore, a study showed that 80% of solar panels will last longer than their warranty and they require little to no recurring maintenance.
The cost of installing a solar pool heater
The cost varies widely depending on the size of the swimming pool, preferred water temperature, overall exposure to the sun, shading, panel direction, climate, typical energy usage and other factors.
In general, the average price can fall in a range of $3,500 to $8,000, assuming your solar heating system covers from 70 to 100 per cent of the pool’s surface area. Glazed panels cost more but these are only required if you’re heating water in temperatures that fall below freezing.
Comparing the cost of solar pool heating systems
You can estimate and compare the costs of using different solar collector models before you buy using the method below.
First, obtain the following information:
- Collector’s thermal performance rating (Btu per day)
- Total number of collector panels or piping for the area needed to heat your pool
- The total installed cost of the system
Then, calculate the collector’s energy output per dollar invested using this formula:
(Btu/day x number of collector panels/piping modules) ÷ total installed cost of system = Btu per day per dollar spent
(28,000 X 4) Btu ÷ $4,000 = 28 Btu/day per dollar spent
If you only know the prices and thermal performance ratings (Btu/day) of the solar collectors, use this formula for the different collectors:
Btu/day ÷ collector price = Btu/day per dollar spent
21,000 Btu ÷ $400 = 52.5 Btu/day per dollar spent
When choosing a solar pool heater, it is important to consider all of the factors involved in the system’s sizing and quality of the design and installation aside from just the installation cost.
Benefits of solar pool heaters
- Increased property value
The rising demand for solar home upgrades means that having solar pool heating can amplify the value of your home.
- No operating costs
After the initial investment cost for installation and materials, there are no other operating costs except for the occasional replacement of wearable parts.
- Longer pool seasons
If your swimming pool is too cold for half of the year, having a solar pool heater can allow you to enjoy your pool all year long.
- Savings on energy
Your utility bill will be reduced drastically since it costs nothing to heat the swimming pool. You are using the sun’s energy to do it for free and the components of the heating system don’t need electricity from your home to function.
- Return on investment
A solar pool heating system can pay for itself within a few years whereas a new gas or electric pool heater creates a consistent cost each time you use it.
A solar pool heater has no internal controls, wiring or moving parts. It can also stand up to a wide range of pH and pool water chemistry. Thus, they can last for years. Furthermore, they come with warranties. With proper maintenance, its lifespan can be extended even longer.
- Environmentally friendly
Solar swimming pool heaters leverage the sun’s energy to heat your pool. They do not create air pollution.
- Dual purpose
The solar pool heater can also be used to cool the water during hot summer months by circulating the water through the solar collector during the night.
Types of solar pool heaters
There are several types of solar collector systems in solar pool heaters:
1. Glazed solar collector
- the covering for absorbing heat is made from industrial-grade rubber or plastic
- suitable for above freezing temperatures
- suitable for indoor pools in cold climates
- cheaper than unglazed
2. Unglazed solar collector
- the covering is made of glass
- used in cold climates which fall below freezing temperatures
- more efficient at capturing heat than unglazed solar collectors
3. Alternatives to an unglazed solar collector
- evacuated tube solar thermal system
- flat plate solar thermal system
- thermodynamic panels
There are 2 types of swimming pools: in ground and above ground. Some solar pool heaters are best used for one type of pool while some can be used for both. Here are the solar heating options available to you:
1. Ground-mounted solar pool heater
The solar collector is placed on the ground, usually next to or near the pool. Installation of this system is cheaper for above the ground pools than for in ground pools.
2. Roof-mounted solar pool heater
The solar collector is installed on the roof closest to the swimming pool. This is usually used for in-ground pools.
3. Floating solar pool heater
This consists of a series of PVC pipes that float on the water while allowing water to flow through the pipes. No installation of any pump or pv system is required.
4. Solar heater mat for pool
This is a solar collector that can be installed with an existing electric pool pump, suitable for above ground pools.
5. Other types of solar gadgets for heating pools
a. Solar Sun Ring
This product is like a solar pool cover, but it has built-in photovoltaic cells to absorb solar energy which then heats the water below.
b. Solar pool cover
A low-cost solution is a pool cover that is more translucent than standard pool covers which enables sunshine to warm up the pool. It also helps to trap the heat and prevent evaporation.
c. Solar pool pump
Instead of installing an entire solar pool heater system, go for standalone pool pumps powered by solar.
d. Pairing your existing solar system with a pool heater
This is for those who have a sufficient amount of roof space to fit both PV panels and solar thermal collectors. Alternatively, install a solar system to cover the power needs of your electric pool heater.
In short, having a solar pool heater is worth it if you wish to have a warmer swimming pool for a longer time through the year, and you want to save money on the heating bill. There are various pool heating solutions for in ground and above ground pools. The best one depends on your budget, the type of swimming pool you have, and whether you want to make use of the existing pool pump system or to have a brand new pool heating system.