M&V Solar Water Heating Guideline - Eskom

Measurement and Verification Standard Guideline for Low Pressure Solar Water Heating Systems v1r1
3.3 Influence of the Local Climatic Conditions on the SWH System
Performance
3.3.1 Climatic Zones in South Africa
The performance of any SWH system is influenced in a great deal by the geographic location
of the installation site and it is extremely seasonal. Thus, the actual installation site will be a
dominant factor in the system thermal performance and related energy savings from the
retrofit.
The average annual solar energy potential per day is shown in Figure 6 and 7. It is evident
that the South African solar potential could be simplified if the country is divided into six
regions according to the availability of solar incoming energy as presented in Figure 8.
Obviously, the same type of SWH system will perform differently if it is installed on different
climatic regions.
Figure 6: Southern Africa average annual solar energy potential per day in [ kWh/m 2 ]
Source [8]
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