The government of Ethiopia placed a high priority on providing access to energy for remoternlocations. Despite this policy and the expenditure of millions of birr, the majority of thernpopulation still remains without access to electricity services today. To meet the lighting andrnother basic energy needs, many households continue to depend on polluting and non-efficientrnenergy means such as kerosene and dry cell batteries. Electrification through grid extensionrnwas the only electrification options available to the rural population in this country. Morernrecently, there is a dramatic increase in the use of renewable energy solutions, mostly off-gridrnsolar PV systems by governmental and non-governmental organizations. Off-grid solarrnphotovoltaic (PV) system is an obvious choice for bringing modern energy supply to the remoternEthiopian communities. In the past ten years, different governmental as well as nongovernmentalrnrnorganizations in Ethiopia have implemented thousands of solar photovoltaicrnsystems for homes and institutions across the four regions in Amhara, Oromia, SNNP and Tigrayrnregions of Ethiopia. However, to date there has not been a major study conducted in regards tornthe sustainability and PV systems design considerations. Accordingly, this study assessed therndifferent systems implemented in the four regions (Amhara, Oromia, SNNP and Tigray regions)rnwith the main objective to identify factors affecting the sustainability of solar PV systemrndissemination thereby suggesting best ways for designing stand-alone solar PV systems for ruralrnapplications. In order to meet these objectives, scientific methodologies were followed whichrninclude literature review, site visit, data collection and analysis. rnAll the necessary data were collected by conducting surveys of solar PV systems installed in thernselected sample Woredas of the four regions, and also by conducting interviews of PV systemrnusers and energy experts working in the respective Woredas, Zones and Regions. The thesisrnpresents the major findings from the result of the data analysis which is evaluated in order tornsummarize the sustainability aspects of solar PV systems dissemination and to propose thernmost feasible solutions for the problems raised by the study. Based on the survey data analysisrnresult, load estimations were done for homes and institutions found in off-grid areas. The solarrnradiation data of the regional capitals were retrieved from NASA which has been taken as anrninput for an optimized PV module and battery design that is simulated using PVSyst. rnThis thesis also examines issues of optimal designing and as such provides optimum sizes ofrnphotovoltaic panels and batteries for two types of homes with different load considerations,rnand for institutions such as schools and health facilities. The findings show that there arerndifferent system sizes that exist for the same kinds of institutions. In addition, similar sizedrnsystems were supplied and installed for all regions. The simulated system using PVSyst shows,rnfor Adama (Oromia region) and Mekele (Tigray region), smaller PV size is needed as comparedrnto Bahir dar (Amhara region) and Hawassa (SNNPR).