Power-to-Gas a growing technology

The Power-to-Gas (PtG) technology converts electric energy into hydrogen or, by subsequent synthesis, into methane or liquid energy carriers. An analysis of Ludwig-Bölkow-Systemtechnik’s(1) PtG database shows that more than 300 PtG projects have been announced worldwide by the end of 2019. During the last 6 months, more construction capacity has been announced than in the last 6 years altogether.

At the same time, PtG systems have increased in size. Several electrolysers with an electrical capacity of more than 30 MW will be built in Germany in the next few years. The projects focus on sector coupling in particular, using hydrogen technologies. Sector coupling links the electricity, heat, and gas sectors as well as the mobility sector and enables a better balancing of fluctuations in renewable energies and CO2-reduced mobility.

Larger plants are also in the planning process in neighbouring countries. However, Germany is assuming a pioneering role, particularly with its “living labs” (within the 7th Energy Research Programme of the Federal Government). Here, hydrogen technologies are used and tested under real conditions at an industrial scale, focusing on regions with a high supply of renewable energies or important industrial sites pursuing particularly attractive concepts.

The Federal Government also supports other H2 regions in Germany in the context of the “HyLand” funding program. In December 2019, 13 “HyExpert” regions and three “HyPerfomer” – regions were selected for the development of H2 concepts and the implementation of specific project concepts.

In addition to using it as an energy carrier, hydrogen is versatile feedstock used, for example, in the chemical, petrochemical, and metal industries. Presently, about 50 million Nm³ of hydrogen day are used in German industry, which is largely produced from fossil sources (“grey” hydrogen), mainly from natural gas. Over 20 million tons of carbon dioxide (CO2) are being released annually as a result. When hydrogen is produced via electrolysis from renewable electricity (“green” hydrogen), no CO2 is emitted. Consequently, German CO2 emissions can be significantly reduced by substituting grey hydrogen by green hydrogen.

Green hydrogen will become competitive in the long run

Today environmentally friendly green hydrogen is even more expensive than grey hydrogen. However, costs are expected to reach parity as a result of improved political and regulatory conditions and declining costs of renewable electricity and electrolysis systems. Applications of the hydrogen produced by PtG include feeding hydrogen into the natural gas grid, with or without prior methanation, employing green hydrogen for direct reduction in steel production and hydrogenation in refineries, and using it in the transport and the heating sector.

(1)Ludwig-Bölkow-Systemtechnik is an associated company of TÜV SÜD AG