Ecuador, due to its geographical location, has solar irradiation of adequate intensity and duration for energy applications. This energy can be used for the production of electricity at residential and industrial level, and under certain conditions it is cheaper than that consumed from the national electricity grid. This article, based on the results obtained using RETScreen, shows the characteristics that the residential photovoltaic system must have, its electricity production and economic analysis for the return on initial investment. Three scenarios are proposed taking into account: a net-metering with the electricity distribution company, the average monthly electricity consumption of residential customers in the city of Guayaquil, and solar irradiation in the town. In addition, the simulation calculations take into account a lower cost of each kWh produced by the photovoltaic system by reference to that offered by the electricity distribution company and thus analyse the economic feasibility of Grid Parity in the city of study.