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Solar Water Heater

Cut your water heating bill by up to 70% with our energy efficient solar water heaters.

More savings.
More reliable hot water.


How the technology works

Solar water heaters work by having a collator which is exposed directly to the sun & is designed to capture as much energy as possible. Water passes through the collator & heats up before being stored in the tank. A circulation pump continues to circulate the water to keep it at the right temperature.

Evacuated tube – solar radiation heats the fluid in the glass tube. This then heats water that passes over a metal bulb at the top of the glass tube. Because there is a vacuum in the glass tube, very little heat is lost to the atmosphere.

Flat plate – solar radiation heats metal tubes in the collector. Water is circulated through the tubes and in doing so is heated up.

This heating supplements the heating required by the electrical element in your geyser. We make use of a controller which allows you to set which times when the electrical element can heat up the water so should the collector not adequately heat the water during the day because of the weather, the electrical element can heat the water.

Cost and Savings

2.4 sqm flat plate fitted onto existing 200L geyser including installation and fittings (inc VAT) =  R 17 214

Solar Water Heater - cumulative savings

Selecting the right Solar Water Heater

The collectors can usually be connected directly to your current geyser; however, if your geyser is older than 5 years, it is recommended that it is replaced when installing the collector. All products and installations comply with the relevant SANS regulations. A pump is used to circulate the water which allows you to install the solar water heater to your existing geyser. The controller also has vacation setting on it which cools the water down at night and prevents the system from overheating when there is little water usage.

Flat plate vs evacuated tube

There are 2 types of SWH collectors: evacuated tube and flat plate. The evacuated tube collector is slightly more efficient than the flat plate, however it is also more expensive. Evacuated tube collectors are better suited for Gauteng as the low night time temperatures greatly reduces the efficiency of the flat plate, especially if the temperature drops to near freezing. In the Western Cape, both a flat plate and an evacuated tube collector would be suitable.

Roof orientation

If you have a roof that has approximately 2.5m x 2m available space and it is within 45 degree from North, then a solar collector is suitable. If you do not have a roof that is within 45 degree from North, a heat pump will be a better option as the electrical element will often have to heat up the water.


The sizing of your collector depends on the number of people in your household. For 1 to 3 people a 15 tube evac or a 2.0 square metre flat plate collector is recommended. For 4 or more people a 20 tube evac, a 2.4 square metre flat plate collector or a heat pump is recommended.

Retrofit vs. new geyser

A retrofit installation is where the solar water heating system is connected to your existing geyser. Replacing the geyser obviously adds extra cost to the system, therefore it is only recommended if your geyser is older than 5 years as the geyser is no longer under warranty.

Direct vs. indirect systems

Solar water heating systems can be direct or indirect. Direct systems circulate water through the collector whereas indirect systems circulate an antifreeze fluid (usually glycol). An indirect system is only used in areas where frost conditions are present, however using evacuated tubes and a direct system with a controller can also be used in frost conditions. Energy Partners uses the evacuated tube direct system as an indirect system is considerably more expensive and requires the glycol to be replaced every 18-24 months.

Pumped vs thermosiphon

There are 2 methods of circulating the fluid: either with a pump or via the thermosiphon effect. If a thermosiphon system is used, the installation geometry is critical as the geyser must be placed above the collector. This means that you cannot use your existing geyser and the new geyser must be on the outside of the house which affects the aesthetics of your house. Using a thermosiphon system also means that the fluid cannot be circulated on command which poses a problem when near freezing conditions are present. Therefore, Energy Partners chooses to only use pumped systems.

Frequently Asked Questions


How much space does a collector take?

The largest collector (Evacuated tube 20) is 2m x 1.6m

What is the expected lifespan and warranty of the system?

The collectors and tanks have a warranty of 5 years; the small components have a warranty of 1 year.

Doesn’t frost damage the collector?

The controller will circulate water when the temperature in the collector drops too low, this prevents damage to the collector. We only use evacuated tubes in frost prone areas so the heat loss is very little. This method is preferred as using an indirect system (which circulates glycol rather than water) adds significant initial costs to the system.