A key motivator for wider deployment of microgrids (small electric networks with distributed generation connected that operate either connected at low and medium voltage levels or isolated mode) is to bring about the decentralization of the generation. This goal is because microgrids use renewable power sources and storage energy systems. However, the microgrids operation represents various challenges for grid-connected microgrids about the power interchanges with the distribution network. If the operation is performed under optimal conditions, there are benefits for microgrid investment. This paper proposes a detailed formulation to operate microgrids with photovoltaic systems and storage. The model can be used with multiple microgrids interconnected considering electricity prices and tariffs. The model corresponds to an optimal power flow approach for microgrids considering some energy storage systems. The mathematical model considers explicitly electricity tariffs. Illustrative results indicate the optimal operation of microgrids considering a load curve; specifically, the microgrid is designed to operate at different operational circumstances. A case includes multiple microgrids interconnected at different electricity prices. The electricity tariffs determine the power interchanges between the distribution network and the microgrid. Such insights about the optimal operation of microgrids provide a wide range of applications, particularly in operation and feasibility of projects.