A promising replacement of fuel for vehicles is hydrogen because of its abundance, efficiency and absence of CO2 emissions. However, one of the main drawbacks of hydrogen powered cars is the dangerous reaction that this gas produces with air that could lead to an explosion. In order to greatly improve public confidence in the safety of hydrogen fuel, to address the technical issues, and thus facilitate the rapid commercialisation of hydrogen powered road transport the present work investigates the performance of Acoustic Emission (AE) for continuously monitoring composite overwrapped H2 tanks in order to detect cracking and damage at an early stage. Two of the most critical elements to identify damage using AE are sensor and couplant selection. For this reason an experimental investigation to compare the performance of commercial AE sensors and microfiber composite (MFC) to detect damage in hydrogen vehicle tanks is presented. In addition, the effect of using different couplants on the AE signal captured has also been investigated.