
Between October 6 and 9, 2025, OPTHYCS carried out its second testing campaign at the facilities of Fundación Hidrógeno Aragón in Huesca (Spain), a partner in the project. In addition to the hosts, Tecnalia, Enagás, and Lumiker (OPTHYCS partners) also participated in these tests, taking another step toward the real-world application of the concepts developed in the project.
In this second testing campaign, the effectiveness of hydrogen leak detection using fibre-optic sensors at a hydrogen refuelling station dispenser was evaluated. To achieve this, the system was directly connected to the dispenser, fibre optics were laid to the dispensing nozzle, and controlled H₂ leaks were induced to measure sensitivity under real operating conditions.
This campaign represents a step forward in the creation of safer and more reliable hydrogen refuelling infrastructures. These tests were the first to be validated directly at the refuelling point, allowing for a comparison between current leak detection sensors and new-generation sensors. These tests enabled the campaign to be carried out in a real environment and on a test bench designed to ensure the repeatability and validation of the results obtained.
With six tests completed, OPTHYCS is moving toward a safer and more reliable hydrogen refuelling infrastructure. OPTHYCS continues to advance toward the real-world application of its new sensor technology that will lead to reinforcing the safety level of H2 applications.


