What is a solar hot water system?
A solar hot water system does not make electricity, but takes energy from the sun in a similar way that a hose does when it is left lying in the sun – but the pipes in a solar hot water system have been designed to work much more efficiently than a garden hose!.
In solar hot water systems, heat from the sun is absorbed through solar collectors. This solar energy heats water, which circulates through the collectors and into a storage tank, ready for use. The storage tank is usually fitted with a ‘booster’ to maintain water temperature during long periods of cloudy or wet weather.
For maximum efficiency, collectors should be placed in direct sunlight for all seasons (to account for winter and summer sun direction). For systems in southern Queensland where there is insufficient roof space between north-east and northwest, they can still provide acceptable performance, however their performance diminishes as the angle of the panels face further south.
What is a split system solar hot water?
For householders who prefer their tank at ground level, this system has the solar collectors on the roof and the storage tank on the ground. These systems require a small electric pump to circulate water through the collectors into the storage tank.
The pump is regulated by a controller, which reacts according to the difference in water temperature between the collectors and the tank. The controller unit also acts as a frost protector by sending warm water from the tank into the collectors when it senses that the water is reaching freezing temperatures.
Panels lay flat on the roof, giving a streamline appearance
No reinforcement is required on the roof structure. As the weight associated with water storage is at ground level
Best for double story buildings or homes where the panels are a long distance from connect into the house as the hot water is stored closer to where you need it.
What is a close coupled (thermosyphon) solar hot water?
It consists of roof-mounted solar collectors with a storage tank positioned immediately above the collectors. As the heat from the sun is absorbed through the collectors, the water inside becomes hotter and lighter, expanding and rising upwards into the tank.
The colder, heavier water is drawn down into the bottom of the collector where it is heated, causing it to move upwards. This circular heating motion is called the ‘thermosyphon effect’.
The greater the difference in temperature between the water in the collectors and the water in the storage tank, the faster the flow between them.
Frees up space around the house – no need for storage tank at ground level.
No re circulating pumps and pipe runs – reducing heat losses and improves running efficiencies.
No electricity required to operate pumps to re circulate the water through the panels
What are the benefits of installing solar hot water?
For most Queensland households, around 28 percent of annual energy use is for hot water. However, by using the sun’s energy to heat water, the average household can reduce its annual hot water costs by around 85 percent when compared to conventional electric systems.
Despite Queensland’s year-round abundance of solar energy, most Queensland households (around 80 percent) use electric hot water systems, which are the single largest electricity consuming item in most homes.
As solar hot water systems provide the greatest potential for savings on energy costs and greenhouse emissions, they make smart sense for homeowners and the environment.
Using the sun to provide your hot water makes sense. It’s energy that’s clean, renewable and costs nothing to run.
Are there any rebates available for solar hot water?
Yes, the Federal Government offer a rebate for the installation of solar hot water systems called “Small Scale Technology Certificates” or “STC”. This rebate can be offered as a discount off the original cost of the solar hot water providing the STC form is signed over to the company offering the discount.
The STC points available to solar hot water system vary’s from system to system so it is beneficial to chose a system that has high STC points.
The value of the STC can change quite often due to fluctuations in the market so it’s advisable to get a re-quote if your quotation is more than 14 days old.
Frequently asked questions about solar hot water systems