Analysis and optimization of a hybrid system for the production and use of green hydrogen as fuel for a commercial boiler

This study analyzes a hydrogen-methane thermal power plant installed in a high school. In this plant, photovoltaic energy is used to produce hydrogen through two alkaline electrolyzers. The hydrogen is stored under pressure and utilized as fuel, mixed with methane in a commercial boiler for heating purposes. A digital twin of the hybrid system was developed, and simulations were conducted using Matlab/Simulink software. The study compares two possible system configurations: in the first one, the energy produced by the photovoltaic array is sufficient to meet the required amount of hydrogen throughout the simulation year; in the second one, the electrolyzers come into operation only when green electricity is available. For each configuration, several simulations were performed, considering variable sizes of the photovoltaic array, hydrogen storage capacity, and hydrogen-to-methane ratio to determine the optimal plant configuration from an economic perspective. Results indicate that, with current operating expense and capital expenditure costs, the system can achieve a payback time of 16 years with 100 % hydrogen combustion, provided the photovoltaic array and hydrogen storage subsystems are sized appropriately. In terms of environmental benefits, the optimized system configuration enables an annual CO2 savings of 155 tons.