This project is based on the study, design, and calculation of a solar photovoltaic installation for self-consumption with surplus for an office building of the company COMERCIAL ELÉCTRICA DEL LLOBREGAT. The main objective is to produce electricity for self-consumption from a 100% renewable source such as solar radiation. Photovoltaic modules are installed on the roof to produce DC electricity. The device that transforms the DC electricity into AC electricity is the inverter. This AC electricity is supplied to the installation without consuming the energy simultaneously supplied by the electrical grid. In this way, clean and renewable energy is generated, helping to stop climate change mainly caused by the usage of polluting energies, thus obtaining significant savings both economically and energetically. In addition, an investment is made that can be amortized in the short/medium term, ensuring that there are profits in the long term. This system consists of the generation of electricity from solar energy for own consumption, thus reducing the electricity bill. According to the current regulation RD244/2019 there are different typologies of installations, the one proposed in this study will be the SELF-CONSUMPTION WITH SURPLUS, which is connected to an internal network and operates in parallel with the subscriber's loads and the network, thus being able to compensate the energy discharged with the commercializing company. In order to cover part or all of the energy demand with photovoltaic energy, it has been considered that there is no limitation of available space, that the roof is flat, free of shadows, and that it is oriented south-west (azimuth = 10°). The equipment proposal consists of a solar photovoltaic installation of 40 photovoltaic panels, with a total power of 10.8 kWp of panel production, which has been oversized to cover the possible losses of the installation itself. Each panel will have an output of 270 Wp after reaching an economic agreement with the supplier. The inverter will have a nominal AC power of 10 kW, which implies that the maximum production to produce the necessary consumption of the offices cannot exceed 10 kW. The operation of the solar system will be as follows: the energy generated by the photovoltaic modules will pass through the wiring in direct current to the inverter, converting the electrical energy from direct current to alternating current for use in the offices. The photovoltaic surplus that may be produced will be managed by the load manager installed in the system. The surplus energy of the solar system will be partially compensated at approximately 0.04 €/kWh. The total budget for this installation will be approximately €16000, with a useful lifetime of approximately 25 years, made with quality components and properly maintained.

Treballs Finals del Màster d’Energies Renovables i Sostenibilitat Energètica, Facultat de Física, Universitat de Barcelona, Curs: 2020-2021, Tutor: Julià López Vidrier