2.2 Residential sector

2018). South Africa has a significant potential for renewable energy with its abundant natural resources of sunlight (Heggie, 2020). Privately installed renewable energy results in energy savings and reduced reliance on grid-provided energy, leading to a positive impact on energy sustainability in South Africa's built environment (Government of South Africa, 2018).

2.2 Residential sector

In South Africa, almost a third (27%) of supplied energy was consumed by the residential sector, according to the South African Energy Sector Report (Government of South Africa, 2018). The residential sector's energy consumption is expected to increase with population growth and economic growth. Over the past 15 years, consumption has risen with more than 10% of the total consumed energy in South Africa (Government of South Africa, 2018). In light of the figures in Figure 1, the residential sector shows a potential for energy savings.

Figure 1: Energy demand by sectors (Government of South Africa, 2018)

Climate around the globe ranges from cold and dry polar climates to hot and wet tropical climates. The sun’s energy heats the land and water masses and primarily influences climatic zones. The climate is also influenced by the topography, geomorphology, altitude, the relation to water masses, ocean currents, patterns of wind, and the vegetation pattern at a regional level.

Figure 2 illustrates the six climatic zones of South Africa according to SANS 10400-XA.

Figure 2: Climatic zones of South Africa (SANS 10400-XA, 2011).

According to SANS 10400-XA (2011), Climatic Zone 2 is defined as ‘temperate interior’, and has the following main characteristics: • Low diurnal temperature range near the coast but range increases in the interior • Four distinct seasons • Summer and winter can exceed the human comfort range • Spring and autumn are ideal for human comfort • Mild to cold winter with low humidity • Hot to very hot summers with moderate humidity.

The following design responses are best used in Climatic Zone 2 (Schmidt, 2013): • Use passive solar principles • High thermal mass solutions are recommended • Use high insulation levels, especially to thermal mass • Maximise north-facing walls and glazing, especially in living areas with passive solar access