This documet shows step by step the procedure of aproject develpement from an analytical and executive point of view. The aim of this work is to explain how a project is started, how it develops and how it ends till the installation start-up. Going through these steps, it is going to be shown the aspects to care about in order to proper design a photovoltaic grid connected self-consumption installation. Some years ago, renewable small-scale projects have started to play a more important role in the society and industry developements. The main idea is to use the plots used for other goals, in the case of study to potabilaze water by several treatments from residual flows, to generate electricity. That way, not just the consumption is reducing but the visual impact of large-scale power plants needed to support the world’s sustainable deveolpement do so.