What is a Solar Water Heater

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A solar water heater, or SWH, uses the sun’s heat to provide a significant part of your household hot water needs. Most SWHs are designed to supplement, rather than replace, existing electric or gas-powered tanks in residential homes and commercial buildings. SWHs are available in a wide range of configurations at varying costs to suit different climates and latitudes.

A typical solar hot water system comprises solar collectors, a storage tank or cylinder and pipes to connect these. The solar collectors are usually (but not always) fitted to your roof and look a bit like photovoltaic solar panels. The difference is that while photovoltaic solar panels convert the sun’s energy into electricity, solar thermal collectors use this energy to heat your water.

During the day the sun’s heat passes through the solar collector tubes and is transferred to water in the storage tank via a coil. The stored water then flows through a heat exchanger and is heated further. This hot water is then piped around your home to supply your showers, baths and appliances.

Your installer will assess your family’s hot water requirements and size the solar collectors and cylinder to best meet those needs. They will also consider whether you prefer a closed loop system that circulates freeze-proof fluid but does not touch potable water, or an open loop system that carries your potable water through the solar collectors. Generally, an open system is more practical in frost-free areas and is cheaper to install.

The solar collectors should be positioned to face south and unobscured to maximise the amount of sunlight they receive. Some SWH systems have a rail that the collectors can be placed on to make this easier, while others require that you build a small rack out of wood or metal to mount your solar panels on your roof. The panels should be angled at 35-45 degrees for best performance and be securely fixed to this mounting system with a few straps or clips.

Once the solar heater is in place it will need minimal maintenance. The manufacturer and your installer will recommend a schedule of maintenance tasks for you to follow. Keeping up with these tasks should ensure that your system continues to work efficiently.

solar water heater While solar hot water systems are generally fairly low maintenance and durable, they do need to be checked from time to time to ensure there are no problems with the components or connections. It is recommended that you have a professional inspect your system every 3-5 years.

While the initial outlay for a solar hot water system is a bit more than a standard gas or electric powered water heater, the long-term savings and environmental benefits should make this investment well worthwhile. It is also worth noting that many states and local councils offer financial incentives for the installation of a solar water heating system. These can include rebates for solar thermal collectors, cylinders and the installation. The cost of a new solar water heater after these rebates and other incentives is often significantly less than the ongoing running cost of a conventional system.