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 |
|
150L |
1-2 |
R400 – R800 |
R150 – R400 |
R1,800 – R4,800 |
|
200L |
1-2 |
R500 – R900 |
R200 – R450 |
R2,400 – R5,400 |
|
200L |
2-3 |
R600 – R1,000 |
R250 – R500 |
R3,000 – R6,000 |
|
200L |
3-4 |
R700 – R1,200 |
R300 – R600 |
R3,600 – R7,200 |
|
300L |
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.