The energy transition will require the use of renewable energy resources that will allow us to reach our decarbonization objectives. In addition to states and institutions, individuals have an important role to play in this transition, particularly with the installation of photovoltaic panels. But for individuals to use this source of energy, they must be guaranteed a financial return that encourages them to take the plunge. Several companies, in a commercial approach, guarantee returns on investment after 2–3 years for any installation. But is the financial profitability always guaranteed? In France, several types of photovoltaic installations are possible, total resale and self-consumption. For each one, the profitability will vary and depends on many parameters such as the initial and daily investment, the irradiation, the electricity buy-back price, and the consumption. This paper explains the calculation methodology for both typologies and shows that currently, in most cases, a self-consumption installation is more profitable than a full resale installation but is far from obtaining the returns on investment predicted by the commercials. If self-consumption is more profitable today, this is due to the fact that the investment (initial or annual) is less important, and that the price of electricity becomes more and more expensive while at the same time the price of resale decreases from year to year
