Solar Geysers

modified: 9 September 2022

Enjoy Economical Hot Water with Ariston Solar Geysers

Most parts of South Africa are blessed with an abundance of sunshine. In fact, the annual daily radiation average for South Africa is around 220 W/m², compared to about 150 W/m² for many parts of the USA, and about 100 W/m² for Europe and the United Kingdom. This makes South Africa's sun resource one of the best in the world. The Northern Cape receives the third-highest annual solar irradiation in the world. While photovoltaic panels (panels for electricity generation) can power an entire home, they are relatively expensive. Solar systems for heating water, more correctly known as solar thermal systems, offer far better returns on much lower investment.

How do these systems work?

Photovoltaic (PV) panels use specially coated silicon wafers to capture light energy from the sun and convert it directly into electricity. Unlike solar water heating systems, PV systems supplement household electricity consumption by converting light, mostly from the ultraviolet part of the spectrum, into electricity. The electricity must be used directly or stored in a battery for later use. An inverter and switchgear are also necessary to convert direct current (DC) from the PV panels or battery to the alternating current (AC) that most households run on. Solar water heating systems are a simpler and cheaper way to exploit the free-to-all source of energy the sun provides. Solar thermal collectors consist of a flat box-like structure with a transparent upper surface. The inside of the box is coated with a light absorbent material, usually matt black in colour, which absorbs heat that gets transferred to a heat exchanging manifold containing water. Convection carries the hot water from the manifold to a tank where it mixes with the cooler water. Systems of this design are known as direct systemsmyAriston. as they do away with a separate heat exchanger and heat transfer fluid and don’t require any antifreeze or refrigerant.

Benefits of Solar Geysers


PV panels can currently only convert around 20% of the energy that they receive from the sun into electricity. The thermal collecters used with solar geysers easily convert 85% or more of the energy received into useable heat. If hot water is the requirement, solar geysers and collectors are the obvious choice. These installations provide pressurised hot water economically throughout your home. They can supply showers, taps and other points of use at temperatures hot enough for most domestic purposes. More importantly, solar geysers with collectors are passive systems. If correctly installed, they automatically provide hot water on sunny days. During bad weather with little or no sunshine, a backup electrical element may be used to provide for any shortfall in hot water. In South African conditions, if the system is correctly sized, the backup element will seldom be needed. Your installation will continue to produce hot water during daylight hours and solar geysers that are properly insulated will retain most of their warmth throughout the night. They operate just as effectively even in the cooler regions of Europe, where they are equally popular. The main difference is that the collectors in the northern hemisphere must face south, whilst the panels need to be north-facing in local installations. Size for size, South African collectors will produce substantially more heat due to the higher irradiation. Choosing a sun-powered water heating solution also has environmental benefits. Apart from their high cost, the manufacture of PV panels generates a significant carbon footprint. Damaged or malfunctioning units constitute hazardous waste and are not easily recyclable. By contrast, the materials used to manufacture passive solar thermal systems are suitable for recycling. Unlike many competing companies, the Ariston Group makes every effort to ensure its products, including solar geysers are made using eco-friendly, sustainable production methods. 

What system is Right for your Home?



Ariston Thermo South Africa offers several energy-saving solutions, including high-efficiency electric water heaters, solar geysers and thermal collectors. If you are tired of the high monthly cost of electricity for your home, consider the Thermo DR direct solar water heater from Ariston Thermo South Africa. Our state-of-the-art solar geysers and thermal collectors capture the sun’s energy directly and will provide all the domestic hot water you need. Our systems are easy to install, can withstand those summer hailstorms common in some parts of South Africa, and their class-leading, stylish, Italian design eliminates any aesthetic concerns. A 100, 150 or 200-litre tank is available to suit the size of virtually any home. Start saving now! Contact Ariston Thermo South Africa and we will gladly assist you with choosing the right solar water heating system for your home.