The KG-series engine became available for orders in late September 2025 after nearly a year of testing at Kawasaki’s facility in Kobe under real-world operating conditions. The system burns a gas-hydrogen mixture in which hydrogen can account for up to 30% of the fuel volume, requiring only minimal modifications to existing gas transmission infrastructure compared with fully hydrogen-based technologies.
The solution is designed as a transitional decarbonization technology. Because older gas engines can be retrofitted, operators can increase hydrogen content without replacing entire power installations. Earlier KG-series models — which have accumulated more than 240 orders since 2011 — can be modified to run on hydrogen-gas blends, extending their lifespan while lowering CO₂ emissions.
Hydrogen combustion presents technical challenges: hydrogen molecules are the smallest of any gas, making leakage through seals more likely and potentially affecting metal durability, while hydrogen also ignites across a wider fuel-air ratio range than natural gas. To address this, the engine includes hydrogen-leak detection sensors and nitrogen purging systems that protect the installation during startup, shutdown, or emergency situations.
The initiative is tied to broader Japanese efforts in hydrogen technologies. In addition to Kawasaki’s stationary engine, similar industrial partnerships — including collaborations between Yanmar and Japan Engine Corporation — have led to land-based tests of hydrogen-powered marine engines, seen as part of a wider push toward versatile hydrogen applications.
A key barrier to large-scale hydrogen adoption remains supply and storage infrastructure, which is still under development. Japan Suiso Energy, together with Kawasaki, began construction in November 2025 on an import terminal for liquefied hydrogen — Japan’s largest storage tank at 50,000 m³ — intended to handle overseas deliveries and scheduled to begin operations by 2030.
The new engine could become an important component of Japan’s strategy to achieve carbon neutrality by 2050, aligning with national policies promoting a hydrogen economy and the use of alternative fuels in energy and transportation.