Everyone loves a good deal. And solar water heating systems are no exception.

The claims in the industry regarding the savings achieved by solar water heating systems differ greatly. There are many sophisticated mathematical models available that are designed to calculate precise savings based on different scenarios. We’ve tried many of them and found them to be quite complicated.

Savings guideline

Based on our experience and feedback from solar water heating customers, we have come up with the following guideline for calculating savings on our systems.

Geyser size No. of people in the house Average monthly electricity bill Average monthly savings Projected Annual savings



R400 – R800

R150 – R400

R1,800 – R4,800



R500 – R900

R200 – R450

R2,400 – R5,400



R600 – R1,000

R250 – R500

R3,000 – R6,000



R700 – R1,200

R300 – R600

R3,600 – R7,200


4 or more

R800 +

R350 +

R4,200 +

Note: The above table is intended to be used as a guideline only.


Factors affecting estimated savings

Actual savings are quite difficult to calculate accurately as there are many different variables that play a role, for example:

  • Electricity pricing structure (dependent on your electricity provider)
  • Hot water usage patterns (showering in the morning vs the evening)
  • Pool pump
  • Gas stove
  • Number of fridges and freezers in the house
  • Heating and air-conditioning
  • Tumble dryers
  • Type of lighting (CFLs etc)
  • Use of timing devices

All of these factors affect the overall electricity use of the household and therefore the associated cost and savings. Your specific combination of factors will ultimately determine the size of the saving you can expect to achieve.

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