Hydrogen combustion engines, KEYOU and Bücker + Essing find all-German agreement
The agreement initially covers the conversion of around 1,000 new diesel engines to hydrogen by the end of 2028 in order to accelerate the market ramp-up for hydrogen-powered commercial vehicles. The conversion of the engines of existing vehicles is expected to begin in larger numbers from 2029.

KEYOU and Bücker + Essing, a member of the Elevion Group and an international specialist for engine reconditioning, have signed a letter of intent for the joint ramp-up of hydrogen combustion engines. As explained by the partners, the agreement initially covers the conversion of around 1,000 new diesel engines to hydrogen by the end of 2028 in order to accelerate the market ramp-up for hydrogen-powered commercial vehicles. The conversion of the engines of existing vehicles is expected to begin in larger numbers from 2029.
The two companies are already working together successfully on engine conversions for KEYOU’s 18t pioneer fleet. With the memorandum of understanding, the existing cooperation will further expanded. Bücker + Essing has many years of experience in converting combustion engines to gaseous fuels. The company already has the necessary capacity to realize the volumes planned by KEYOU in the coming years.
Trust in hydrogen combustion engines for heavy-duty transportation
The aim of the intensified cooperation is to retrofit more than 1,000 new engines by the end of 2028 as part of the series planned by KEYOU. From 2029, the retrofitting of used vehicles will begin in parallel with the new vehicle business. In the future, it is planned to retrofit around 5,000 engines per year from 2029.
“We are proud to support this innovation project with our many years of expertise in the conversion of diesel engines to gaseous fuels and thus make an important contribution to the decarbonization of heavy goods transportation,” said Ralf Wöllert, Managing Director of Bücker + Essing. “The cooperation with KEYOU is an important step for us to further expand our knowledge lead in the field of hydrogen. We are convinced that hydrogen engines will play an important role in the technology mix of the future in the long term.”
“Decarbonizing the transport industry is a key lever for achieving a climate-neutral future. As a pioneer and innovator in the field of holistic decarbonization solutions, we are focusing in particular on renewable energies such as hydrogen. This project shows how technological innovation and strong partnerships can successfully shape the transition of mobility,” added Jaroslav Macek, CEO of Elevion Group.