In Africa, there is an enormous requirement for development of infrastructure in both underdeveloped and developed cities experiencing an exponential growth in population. This strain on existing infrastructure calls for advancement in areas such as energy, construction and engineering. Likewise, continuous rise in global concerns (and specifically Africa) of greenhouse gas emissions has called for sustainable construction and thus the use of sustainable building technology products (SBTPs) that are renewable, reusable or recyclable. It is essential to use products manufactured from pure and clean sources to minimize negative environmental degradation in the continent. The photovoltaic (PV) system is believed to be the most popular SBTP. PV systems have attracted tremendous interest in research and industry. It has become technologically mature, economically sustainable and has also recorded an exponential growth in installation worldwide. But despite its popularity, PV is widely used ineffectively. Thousands of products are manufactured and available with distinctive features. Users face challenges of multiplicity in PV components—their types, sizes, costs, outputs—the effect of each component that has on the overall design of the PV system. Furthermore, it is challenging for people who wish to purchase and install SBTPs to find the precise information (from vast available sources) that would enable them to make informed decisions about which technologies to select. The study discusses PV systems and establishes a selection criterion for different projects. Furthermore, the study uses process mapping techniques as an approach for the design and selection of a suitable PV system and its components. The mathematical computations required to support the design process have been developed and are presented. A case study example is used to demonstrate the application of the approach.