How Does a Solar Hot Water System Work

Nowadays, energy efficiency is more important than ever. Solar water heating systems are not just environmentally friendly, they’re also a smart, cost-saving alternative to traditional water heating.

So, if you’re wondering how solar hot water works or what it takes to set up a solar hot water system, you’re in the right place. This blog will cover important things you need to know about solar hot water systems. Let’s dive into it.

Solar Hot Water System: How It Works

A solar hot water system uses the energy from the sun to heat water for various uses, like bathing, cleaning, and cooking. Unlike traditional water heaters that rely on electricity or gas, solar systems harness renewable energy, which means they can help reduce your energy bills.

If you are wondering “how solar hot water works?”, simply put, solar collectors capture sunlight and convert it into heat, which is then transferred to the water stored in a tank.

What Are the Benefits of Solar Hot Water Systems?

1. Energy Savings

A solar water heating system can reduce your energy bills by up to 65%. Given that water heating makes up a significant portion of household energy usage, installing a solar water heater can lead to substantial savings in the long run.

2. Environmentally Friendly

Solar hot water systems are powered by renewable energy, reducing your carbon footprint. By relying on the sun’s free energy, you help reduce greenhouse gas emissions and conserve fossil fuels.

3. Government Incentives

In many regions of Australia, including Sydney, there are government rebates and incentives available for those who install solar hot water systems. These incentives can reduce the upfront cost of installation, making solar hot water even more affordable.

4. Low Maintenance Costs

Once installed, solar hot water systems require minimal maintenance. The only regular maintenance required is ensuring the solar collectors are clean and free from debris.

Understanding Solar Hot Water System Configurations

1. Direct Solar Hot Water System

In a direct solar hot water system, water flows through pipes inside the solar collectors, where it absorbs heat from the sun. Once heated, the water is sent back to a storage tank for later use. This process continues as long as sunlight is available, ensuring a steady supply of hot water throughout the day.
This type of configuration is most commonly used in areas with mild weather conditions. However, direct systems aren’t ideal in areas where freezing temperatures are common, because the water inside the pipes can freeze and cause damage to the system.

2. Indirect Solar Hot Water System

An indirect solar hot water system operates similarly to a direct system, but with a key difference. Instead of heating water directly, it uses a solar fluid (often antifreeze) that is heated by the sun. The heat from this fluid is then transferred to the water via a heat exchanger.
This configuration is ideal for regions where freezing temperatures are a concern, as the solar fluid is protected from freezing, preventing damage to the pipes and ensuring reliable performance even in colder climates.

Installation Options for Solar Hot Water Systems

1. Roof-Mounted Solar Hot Water Systems

A roof-mounted system consists of solar collectors and a storage tank placed on your roof. This setup uses a principle known as thermosiphon, where heated water naturally rises to the storage tank, while cooler water is pulled into the collectors for heating.
Roof-mounted systems are space-saving and cost-effective. However, your roof needs to be sturdy and have good sun exposure to work efficiently.

2. Ground-Mounted Solar Hot Water Systems

A ground-mounted system positions the storage tank at ground level, with the solar collectors installed on the roof.
While ground-mounted systems provide more placement flexibility, they involve a higher installation cost due to the additional materials, labour, and plumbing needed to connect the tank and collectors, as well as the space preparation for the installation.

Types of Solar Hot Water Systems

Understanding the different types of solar hot water systems is key to finding the right one for you. There are two types of solar water heaters, and those are:

1. Active Solar Water Heating Systems

These systems use electric pumps to circulate water or solar fluid through the collectors and storage tank, making them more efficient, especially on days with less direct sunlight. Active systems are typically used when more consistent heating is needed

2. Passive Solar Water Heating Systems

Passive systems rely on natural convection and thermosiphon principles. They are simpler and have fewer moving parts, which means they are more reliable and require less maintenance. However, they are not as efficient as active systems, especially in cloudy or shaded conditions.

How Much Does a Solar Hot Water System Cost?

In 2025, the average cost for a solar hot water system in Sydney ranges from $3,500 to $7,000 for a basic installation. The exact cost can vary depending on the system size, brand, and additional features like smart controls or larger storage tanks.

As mentioned before, the cost of installing a solar hot water system can be reduced through government rebates and incentives. These rebates, such as those available under the Small-scale Renewable Energy Scheme (SRES), can save you hundreds or even thousands of dollars, depending on the system and your eligibility.

How to Check If Solar Hot Water is Working

Once your solar hot water system is installed, it’s important to check if it’s working properly. Here are a few simple checks you can do:

• Check the temperature: Run hot water and feel if it’s hot enough. If it’s not reaching the temperature you need, it could indicate an issue with the system.
• Inspect the collectors: Ensure that the solar panels are free of debris, dirt, and dust that could block sunlight.
• Check the system’s display: Many systems have a digital display or gauge that shows the water temperature and performance status.
• Monitor the backup system: Ensure the backup heating element (like an electric booster) is activated when solar power isn’t enough.

Conclusion

Solar hot water systems are an excellent way to reduce your energy bills and minimise your environmental impact. If you’re interested in installing a solar hot water heater, get in touch with our team at Fix N Flow. You can call us at 1300 319 275 or submit our online form. It’s an investment that will not only save you money in the long run but also contribute to a greener, more sustainable future.