In the past years, the number of installations using photovoltaic panels has significantly increased in Brazil as well as in the world. Even though it has the advantages of being installed next to the loads, and usually generates more energy in demand peak hours, the technical and financial viability of this project is yet a challenge to be overcome due to the complexity involving installation and equipment costs. One of the means of overcome these challenges is providing information to energy consumers so that they can decided, in a more assertive manner, how to invest on such a project. The scope of this paper aims in providing detailed information, to the big commercial consumers about the technical and commercial aspects involved in the development of these projects, highlighting de advantages and the disadvantages of its implementation. The goal of this paper is to present a detail guideline for the installation of photovoltaic panels in commercial establishments, taking into account the technical and financial aspects of the project such as choice of equipment, expenses with maintenance, generation capacity, return of investment, elaborating a detailed cash flow.