The focus of this master thesis is on the economic and affordability analysis of small off-grid photovoltaic systems in rural areas of Sub-Saharan Africa (SSA). In order to grasp the motivation and importance of modern energy services, this paper also gives an overview of the relevant context for electricity (e.g. political, social and economical situation in SSA) and reviews the literature of electricity access, consumption, production, affordablitlity and rural electrification in the region. Afterwards, the PV potential, the PV market and the PV technology applicable for small off-grid usage in SSA are discussed. This sets the stage for an economic analysis of three exemplary PV systems. The PV systems analysed are a 5W picoPV, a 50W SHS, and a 100W SHS system. The economic analysis uses present value calculations (including reinvestment, O&M, Management costs and depreciation), calculations on monthly financing costs (assuming a 10% annual interest rate) and LCOE calculations (including a sensitivity analysis). Furthermore, the available household budget for electricity is estimated for 47 SSA countries using income quintile data (of 43 SSA countries), GDP per person data and an estimated household size (of 5 persons). The monthly financing costs together with the available household budget for electricity are then used to assess the affordability of the PV systems that have been examined. The results in this paper indicate that a 5W picoPV system is competitive with the substitutes, kerosene, candles and batteries, in average SSA households. It is also affordable for 75% of the rural population in SSA (under good financing conditions e.g. monthly payments, 3 years financing period, 10% interest rate). Furthermore, it is shown that SHS systems can be more economical than diesel in remote areas with high irradiation, but have only limited affordability. Between 19% (100W with 10 financing period) and 29% (50W with 5 years financing period) of the rural population could afford such systems.