An Interactive Menu-Driven Design Tool For Stand-Alone Photovoltaic Systems

Abstract

The use of Photovoltaic (PV) systems to meet energy demand in rural or remote regions of the world is growing at a very fast pace. Rural electrification projects in developing countries have relied primarily on subsidies from both the government and the national utility. Since using the national grid to meet energy demand in these areas has been found to be quite expensive over time, governments in developing countries have turned to photovoltaic technology as a means of providing electricity needs to their rural population.

To facilitate the use of PV systems in developing countries, the author has developed an interactive menu-driven design tool called PVONE that may serve as a guide to engineers and government officials to decide whether a stand-alone photovoltaic system is feasible at a location. PVONE consists of three parts - insolation, system design and economic analysis. In order to predict insolation, PVONE first utilizes the clear sky insolation model that is based on latitude, longitude and altitude of a location. Then it incorporates the standard classification criteria to classify the days of a month according to day types. Based on how the days are classified, a new set of insolation is predicted. For system design, the PVONE program is used to determine the array characteristics based on the chosen photovoltaic module, the system design load and the daily insolation at the location. To determine whether the proposed system is feasible at the location, the PVONE program performs an energy output analysis and economic analysis. The system designed is considered feasible at the location only if it satisfies the load demand and has a positive net present value.