PEM electrolysis

Electrolysis is the process of splitting water (H20) through a membrane into hydrogen (H2) and oxygen (O2) by applying an electrical current.

There are two main commercial technologies today: alkaline and PEM (proton exchange membrane) electrolysis. Alkaline technology has been used for many decades in industry to generate hydrogen in large quantities and can be considered a very mature technology. PEM technology is more recent and is characterised by a higher efficiency (more hydrogen produced per kWh of electricity), a smaller footprint (more kg of hydrogen produced per m³ of cell stack) and better capability to operate under flexible operations. These characteristics make PEM technology an excellent candidate to balance renewable power, and the PEM technology presents a high cost reduction potential through mass production.

In the HyBalance project, the PEM electrolyser will be able to generate 230 Nm³/h of hydrogen (+/- 500 kg/day). The general aims of the HyBalance project are to demonstrate the highly dynamic operation of the PEM electrolyser to provide grid balancing services, a high efficiency over long time duration and a high level of availability (thanks to a dual cell-stack design).

At the conclusion of this project, the expectation is for PEM technology to be fully validated for commercial applications.