Abstract:
Informal settlements, also known as slums or shanty towns, are characterised by rapid and unstructured expansion, poorly constructed
buildings, and in some cases, they are on disputed land. Such settlements often lack basic services, such as electricity. As a result,
informal settlement dwellers turn to hazardous alternative sources of energy, such as illegal electricity connections and paraffin. Solar
power is a clean and safe alternative. However, informal settlements are often located on undesirable land on the urban fringe where
the topography may hinder the use of solar energy. The high density of dwellings could also be a hindrance. Therefore, the solar
potential needs to be assessed before any implementations are planned. Solar potential assessment functionality is generally available
in geographic information system (GIS) products. The nature, cost and accessibility of datasets required for the assessment vary
significantly. In this paper, we evaluate the results of solar potential assessments using GRASS (Geographic Resources Analysis
Support System) for a number of different datasets. The assessments were done for two informal settlements in the City of Tshwane
(South Africa): Alaska, which is nestled on a hill; and Phomolong, a densely populated settlement with a rather flat topography. The
results show that solar potential assessments with open source GIS software and freely available data are feasible. This eliminates the
need for lengthy and bureaucratic procurement processes and reduces the financial costs of assessing solar potential for informal
settlements.
