Design and Implementation of a Smart IoT-Based Energy Management System for Photovoltaic Systems with Micro-Inverters

Solar energy has become an important energy source and a sustainable solution in recent years. The European Union is promoting the use of photovoltaic systems on balconies and walls with micro-inverters ranging from 500 to 1,000 watts. Given that inverters require a certain amount of power (around 70 watt) to start operating, this means that you lose a certain amount of energy in the morning and afternoon during the periods when the energy generated is not sufficient to start the inverter. In many cases, the installation of such systems consists of at least two sets—micro-inverters with the required photovoltaic panels—to generate up to 1,500 watts. This paper focuses on a low-cost solution for managing two micro-inverters, utilizing and optimizing the management of the generated electrical energy by routing the sum of the power, during periods of low energy production, to a single micro-inverter, thereby utilizing energy that would otherwise be lost if routed to each micro-inverter. When the energy produced by the photovoltaic panels increases, the system activates the second micro-inverter as well. It is worth noting that the total power output on a sunny day for each micro-inverter ranges from 4.2 to 4.5 kWh—that is, a total of approximately 9 kWh for two micro-inverters—while after implementing the system, the total power output is 10.2 kWh, which means an additional 1.2 kWh of power. In percentage terms, the increase in power output is 13.5%. Since the device supports wireless data transmission (Wi-Fi), it is possible to monitor the system in real time. Furthermore, it should be noted that this study contributes to sustainability by increasing the efficiency of photovoltaic systems as a renewable energy source, and, given that the proposed solution is low-cost, this makes it sustainable from both an economic and an environmental standpoint.