Hydrogen Generation from the Wastewater of Power Plants via an Integrated Photovoltaic and Electrolyzer System: A Pilot-Scale Study

Abstract

This study presents the first work that investigates a preliminary design generating hydrogen from the wastewater of coal utility boilers via an integrated photovoltaic (PV)−electrolysis system. Connecting solar panels, which generates electricity, to an electrolyzer to split water molecules to hydrogen and oxygen is an attractive method to generate hydrogen. A numerical model is developed for the integrated PV solar panels and polymer electrolyte membrane (PEM) electrolyzer. Parallel solar panels and series PEM electrolyzer cells are considered in the present work to reach the optimum arrangement. The essential losses including the activation and ohmic overpotentials and the required energy for rotary equipment (compressors and pumps) are considered in the model. The effect of the working temperature, solar irradiation, and charge transfer coefficient on the efficiency of the system is investigated. The calculated efficiency of the PEM electrolyzer and PV solar panels is in the range of 60−62.5% and 18−20%, respectively. The efficiency of the integrated PV electrolyzer increases as solar irradiation increases. Of particular interest is the potential application of the present design in Texas, which generates 1.43 × 10 4 Nm 3 /year of green hydrogen for $4.67/kg H 2 by only scaling up by 11. This model provides valuable insights for the large-scale hydrogen generation from power plants' wastewater via the coupled solar energy and electrolysis system.