Fraunhofer Team Develops Compact ‘Green’ Hydrogen Cell

In a groundbreaking development, specialists at Fraunhofer have achieved a major milestone in the field of renewable energy with the creation of a tandem module capable of producing solar-generated green hydrogen independently. This achievement is part of the Neo-PEC joint research project, which aims to revolutionize the way hydrogen is produced and utilized.

Traditionally, electrolysis has been used to break down water into hydrogen and oxygen, with the electricity required for the process often coming from non-renewable sources. However, by utilizing renewable energy sources such as solar panels, the resulting hydrogen is classified as "green" hydrogen. The challenge lies in the size and maintenance requirements of conventional electrolysis equipment.

The Neo-PEC project introduces a novel approach by directly harnessing solar energy to split water using a photoelectrochemical cell (PEC). This innovative solution, developed by researchers from three Fraunhofer institutes, offers a modular and scalable system for hydrogen generation and supply powered entirely by solar energy.

Within the tandem cell, specialized glass coated with semiconducting materials on both sides plays a crucial role. When sunlight interacts with the glass, one side of the module absorbs short-wavelength light, while the other side captures long-wavelength light that passes through the upper layer. As a result, hydrogen is released on the reverse side (cathode) while oxygen is produced on the upper side (anode).

Arno Görne, a manager at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS, highlighted the significance of the vapor phase process used to create nanometer-thick layers on the glass. These structures enhance reactor activity and material properties, contributing to optimized performance. The integration of photovoltaic elements in the module provides additional voltage, enhancing efficiency and accelerating hydrogen production.