On May 10, 2017, a Hydrogen Sensor Workshop was held in Brussels, Belgium. The workshop was jointly organised by the sensor test laboratories at the Joint Research Centre (Petten, Netherlands) and the National Renewable Energy Laboratory (Golden, Colorado, United States), with assistance from the Fuel Cell and Hydrogen Joint Undertaking. The purpose of the workshop was to bring together stakeholders in the hydrogen community with an interest in hydrogen sensors, with a special focus on the ability of existing hydrogen sensor technology to meet end-user needs in applications for hydrogen as an alternative fuel. Participants included sensor manufacturers, end-users, and experts from sensor test laboratories. The main performance gaps hindering the deployment of hydrogen sensors were discussed. From the end-user perspective, numerous gaps were identified in which existing sensor performance capability does not fully meet their needs. For most safety applications, the metrological performance of current hydrogen sensors is adequate, but improvements are still needed. The most critical metrological gap remains sensor lifetime, which includes both the functionality of the sensor (i.e., does the sensor work) and long-term signal stability (i.e., does the sensor need to be recalibrated). Also, for many applications, such as process control and critical safety scenarios, faster response times and improved sensor accuracy are necessary. Maintenance and calibration requirements were identified as a key issue. Certification requirements of hydrogen safety sensors were also identified as a critical barrier. Sensor manufacturers noted that the cumbersome certification requirements can significantly impact sensor cost, especially for a limited market. The complex certification requirements also impacted end-users who often found that sensors with required listings were not available. Simplifying and harmonizing certification requirements were identified as a critical topic requiring further attention and support. In terms of standardisation, the performance requirements for sensors for automotive applications were also mentioned as a critical gap. The following table summarizes the high-priority gaps identified in the workshop that impact the performance and use of hydrogen sensors by end-users. A more complete gap analysis is provided in the following report. In addition to the identification of gaps and barriers, the workshop discussed strategies to address the gaps.
