Optimal Design of a PV/Hydrogen-Based Storage System to Supply Heat and Power to a Direct Air Carbon Capture System

Abstract

Direct air capture (DAC) technology aims to curb the leading cause of global warming by reducing atmospheric carbon content. The DAC system uses thermal energy to desorb captured carbon, with its primary components powered by electrical energy. In this research, an approach integrates hybrid photovoltaic, with spectral splitting optical filtration (PV/SSOF), and hydrogen-based energy storage to provide the required thermal and electrical energy for the DAC system, thereby minimizing environmental impact. To achieve this goal, a mixed-integer linear programming (MILP) optimization model is formulated to minimize the project's lifecycle cost, and the problem is solved by the particle swarm optimization (PSO) algorithm. The model determines the optimal configuration of the system, including the number of PV panels, hydrogen tanks, electrolyzers, fuel cells, and heat buffer tanks. The study tracks the system's performance by assessing how much the PV system meets heat and power requirements. A real-world case study from an industrial city located in the eastern region of Saudi Arabia is presented to showcase the practicality of the optimization model. Three configurations were considered to study the techno-economic viability: standalone with and without a boiler and grid-connected. A sensitivity analysis is conducted to examine techno-economic viability and obtain managerial insights. It is found that the grid-connected system is economically favorable and thermodynamically efficient due to its almost 19% cost reduction for electrical energy and 17% for exergy compared to a system without a boiler. Furthermore, a smaller electrical energy-exergy cost gap shows the system's energy conversion efficiency with low losses.