Solar energy in Johannesburg, South Africa
Average irradiation 5.58 kWh/m²/day · ~1629 kWh per kWp per year
Monthly solar irradiation & temperature in Johannesburg (NASA POWER)
| Month | Irradiation (kWh/m²/day) | Avg temp (°C) | Est. production per kWp (kWh) |
|---|---|---|---|
| Jan | 6.67 | 21.6 | 162 |
| Feb | 6.29 | 21.4 | 153 |
| Mar | 5.58 | 19.9 | 136 |
| Apr | 4.73 | 16.7 | 115 |
| May | 4.34 | 13.3 | 105 |
| Jun | 3.95 | 10.0 | 96 |
| Jul | 4.29 | 9.9 | 104 |
| Aug | 5.04 | 13.1 | 123 |
| Sep | 6.03 | 17.3 | 147 |
| Oct | 6.47 | 19.9 | 157 |
| Nov | 6.83 | 20.7 | 166 |
| Dec | 6.80 | 21.4 | 165 |
Solar potential of Johannesburg explained
Johannesburg receives an average of 5.58 kilowatt-hours of solar energy per square metre per day, measured over four decades of satellite observation. In practical terms, every kilowatt-peak of installed PV capacity yields about 1629 kWh of electricity per year here, assuming a well-oriented system with a typical 80% performance ratio. This places Johannesburg among the stronger solar locations globally — comparable to southern Spain or California.
Frequently asked questions
Is solar worth it in Johannesburg?
With 5.58 kWh/m²/day of average irradiation, a 1 kWp system in Johannesburg produces roughly 1629 kWh per year. That is an excellent solar resource — payback periods are typically among the shortest worldwide.
How much electricity would a 5 kW system produce in Johannesburg?
Approximately 8,000 kWh per year — enough to cover a large share of a typical household's consumption.
What data is this based on?
Long-term satellite observations from NASA POWER (1981–present) and the PVGIS SARAH3 database, assuming a performance ratio of 80%.
Compare with nearby cities
Cairo (5.9) · Casablanca (5.3) · Lagos (4.6) · Nairobi (5.5) · Cape Town (5.3) · Kinshasa (4.6) · all cities →