Management of photovoltaic excess electricity generation via the power to hydrogen concept: A year-round dynamic assessment using Artificial Neural Networks

Abstract

This paper assesses energetically and economically the power-to-hydrogen concept by exploring the excess power resulting from the mismatch between the photovoltaic (PV) generation and the electric demand of a medium-size commercial structure located in Morocco. The variability in the building electric load is considered and the power flows from the PV field to the building are predicted using Artificial Neural Networks for a time-resolution of 15 min. A MATLAB code was implemented to estimate the instantaneous hydrogen production based on a semi-empirical mathematical formulation of an Alkaline type electrolyzer with a nominal capacity of 15 kW. These combined approaches are for the first time adopted to evaluate the feasibility of integrated PV hydrogen systems under the Moroccan context. Using a set of 5 electrolyzers coupled to the 104 kWp currently installed solar PV field, it was possible to generate about 18,622 Nm3/year of hydrogen by exploring the PV excess power. The overall efficiency of the integrated system ranged from 9.5% (in March) to 10.1% (in May). Such an approach allowed enhancing the effective efficiency and capacity factor to values of 9.873% and 26.87%, respectively compared to 6.325% and 10.163% for the base case scenario without hydrogen systems. From an economic perspective, it was found that the integrated PV-hydrogen plant engendered levelized cost of electricity and hydrogen of 12.56 c$/kWh and 21.55 $/kg, respectively.