Economical and technical Investigating an off grid and on grid 30 kW photovoltaic power plant in kashan

The use renewable energy and substitute fossil fuel sources with it is the important goals of country. Used of renewable energy is help to sustainable development of the country. Fossil fuels resource are non-renewable and have highly pollutant then need to follow a resource these are clean, cheap and renewable. Solar energy is biggest energy source in the world. One of the common methods to extracting solar energy is used photovoltaic cells. A PV cell is normally made by silicates. It has no moving parts. Therefore In theory they can give permanently electricity for infinite time without eroding work. But the conventional in has a maximum life 20year. In this study investigated the off grid and on grid 30kW PV system in economically and technically aspect by using Ret screen program. Then calculated the payback period for the various state. In out-of-network state the initial cost is higher because of need high capacity battery. So off grid system has investigated economically according to cost of connecting to network .according to calculation the payback period for on grid and off grid system is 2.4 and 21.6 years respectively.