Solar water heaters are a simple, reliable and highly efficient method to heat water.  Solar water heaters use the abundant and free energy from the sun to heat water.  This can reduce water heating costs by up to 90%.   Solar water heaters cost more than electric water heaters to purchase and install but are cheaper over time.  Solar water heaters can payback the purchase cost difference within several years but can last for many more years.  With regular maintenance it is not uncommon for solar water heaters to last 20 years or more. 





Solar water heaters come in two basic types: direct and indirect.  Direct solar water heaters circulate water directly through the solar collectors.  Indirect systems circulate a special heat exchange fluid through the collectors which is kept separate from the water.  A heat exchange system, usually a jacket around the storage tank, allows the transfer of heat from the heat exchange fluid to the water.


Direct systems are used where water quality is good and the climate mild.  Poor water quality can cause corrosion or blockage of the collectors.  Low temperatures can freeze the water which could damage the collectors.  Indirect systems are used in colder climates and where water quality is poor.  The heat exchange fluid can handle a wide range in temperatures ensuring the integrity of the solar water heater.  



Thermosiphon System

A thermosiphon system is the most common and popular type of solar water heater.  It consists of highly efficient solar collectors that absorb heat from the sun and a storage tank that holds the water.  A thermosiphon system is installed facing the sun, usually on the roof of a building.  Cold water or the heat exchange fluid flows into the bottom of the collector and rises to the top as it is heated by the sun. The process continues until the water in the tank is fully heated.  

Split System

A split system differs from a thermosiphon system in that the storage tank is not located with the collectors and is usually located at ground level either inside or outside.  A pump circulates the water or heat exchange fluid to the collectors and back to the storage tank.   Split systems require less roof space and put less weight on the roof.  The water temperature in the storage tank is also able to be boosted by other means such as gas, electric or heat pump heating.

  • Optimal performance across a wide range of solar conditions
  • Suitable for regions with cold climate and poor water quality 
  • Wide range of product options to meet hot water requirements


  • Save 60-90% of water heating energy costs
  • Reliable, low maintenance and long lifespan
  • Lower lifetime cost compared to electric water heaters
  • Significant reduction in greenhouse gas emissions


Solar water heaters can be used for an enormous range of applications from the smallest household to the largest commercial or industrial application.  Whether 100 or 1 million litres of hot water is required solar thermal can be part of the solution.

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