Your specific geographical location contributes considerably towards solar irradiation and is important to know when designing a solar energy system.
Solar irradiation is the amount of energy emitted from the sun onto the surface of the earth and it varies across latitudes. South Africa is one of the countries with the highest solar irradiation levels in the world. Optimal solar panel placement increases the efficiency of the solar energy system which allows for more energy to be absorbed and higher energy yield.
Have a look at the map to see the irradiation levels of your location. Red means high, green means (relatively) low.