Hydrogen has been seen as a key to the energy transition for years, but the cost of converting it into electricity has been too high. Researchers at the Karlsruhe Institute of Technology (KIT) have now developed a turbine that does without the energy-hungry compressor. They broke NASA's runtime record by more than 20 percent in the process. From 20 April they show the setup at Hannover Messe.
What Losing the Compressor Means
In conventional gas turbines, the compressor consumes a significant share of the energy produced. It squeezes the air before it reacts with hydrogen in the combustion chamber. The KIT team replaces this step with pressure-gain combustion: detonation waves inside the combustion chamber generate the needed pressure through a fluid-dynamic instability. No moving parts, no compressor drive. That saves energy and makes the turbine lighter and more robust.
The practical consequence: the same amount of hydrogen yields more electricity. The higher efficiency significantly improves the economics of hydrogen power plants, which was one of the main obstacles to wide deployment of this technology.
303 Seconds Against 250
The proof came from a practical test: the KIT setup ran stably for 303 seconds. The previous world record, held by NASA, was 250 seconds, achieved in 2023 during rocket propulsion experiments for space missions. The KIT team exceeded that by more than 20 percent. At the same time, they produced electricity with a compressor-free hydrogen turbine for the very first time. Both together are firsts in energy engineering.
For years the researchers had worked to keep the detonation waves controlled. An uncontrolled detonation damages the setup and cannot be used. The key lay in the precise tuning of flows, pressure waves and vortex structures inside the combustion chamber. That this now works for more than five minutes shows the technical maturity of the approach.
To put the result in context: pressure-gain combustion is not a new concept. The basic idea has existed for decades, but in practice it repeatedly failed because detonation waves could not be stabilized. Earlier experiments managed short pulses but no group had previously run the reaction in a controlled way for several minutes and extracted electricity. KIT has done exactly that.
Applications and Outlook
The KIT team sees early commercial applications in decentralized power plants that store surplus electricity from renewables as hydrogen and convert it back when needed. In the long run, aviation could also benefit. A lighter, compressor-free turbine would substantially reduce the weight of hydrogen propulsion for aircraft.
Teams in the US, Japan and France are also researching similar approaches. NASA's record, broken by KIT, emerged in 2023 from a space programme, under different conditions than a ground application. The KIT result is the first successful demonstration for terrestrial electricity generation, which makes it more relevant to the energy industry than earlier academic lab values. The next step is a pilot plant in the megawatt range.