## 3 Results
### Current Status, Challenges and Future Developments
#### 3.2.4 Renewable Hydrogen End-Uses
[137] use GIS to visualize the results of their research, which is focused on the analysis of hydrogen demand in three different scenarios for road transport in fourteen G20 countries. The integration of the data into GIS has faced the challenge of low data standardization across countries, making it difficult to find robust and compatible databases among the different states analyzed. GIS techniques are often complemented with other geospatial techniques to increase the accuracy of the studies. [PERSON], [PERSON] and [PERSON] [139] combine GIS with GPS to analyze the effect on emissions reduction of incorporating supercapacitors into a PEMFC-based propulsion system. The results show a 46.2% improvement in emissions due to the incorporation of data such as slope or traffic. However, with this combination it is not possible to include eventualities such as a crosswalk, so they propose to include IoT sensors to monitor vehicle behavior in real time. The combined use of GPS and GIS enables comparative studies of sustainable mobility solutions based on real operational data. [PERSON], [PERSON] et al. [136] used a combination of GIS and satellite imagery to analyze the relationship between occupied area and HRS capacity. In this case they found that of the 773 HRS they initially identified in the United States (US), they were only able to analyze 134 due to low image quality or the absence of geolocated data. The low image quality prevented them from identifying which infrastructures belonged to the HRS and which did not, especially in those HRSs included in other refueling stations. [PERSON], [PERSON] et al. [134] installed a geolocated IoT system in the exhaust system of a vehicle using different blends of biofuels and hydrogen, with the objective of analyzing the impact of emissions. The incorporation of such an IoT system required modifying the exhaust system to include sensors. GIS is also the predominant technique in stationary applications such as industry and the residential sector. In this case, the general use of GIS is the integration of different data from different sources and morphologies, such as meteorological data, renewable resources, or consumption profiles. [PERSON], [PERSON] et al. [158] propose a GIS-based framework with the ability to compare different energy systems and consumer clusters. The advantage provided by GIS is the automation of the selection of optimal locations using clustering algorithms. The availability of open data and computational time are the main barriers encountered. In the case of power generation, the combination of GIS and real-time monitoring stands out. [PERSON], [PERSON] et al. [161] applied such a combination of technologies in an extreme environment such as Antarctica. Real-time monitoring allows for increasing the accuracy of the control system of the power plant based on PEM technology. In this case, the GIS allows to integrate climate data and to improve the reference parameters of the control system, as well as to provide a solid basis for extrapolating the results to other regions. Finally, geospatial techniques based on CV and thermographic imaging have a significant impact during the manufacturing process. The performance and lifetime of components such as FCs depend on highly accurate manufacturing process that minimizes defects. The most critical component is the polymer membrane. [PERSON], [PERSON] et al. [165] used a thermographic camera to detect hot spots during the operation of an FC. A hot spot can identify a manufacturing defect and can even be classified according to its shape and intensity. In the same line of research, [PERSON], [PERSON] et al. [163] apply CV together with deep learning algorithms to automatically identify and classify defects that may occur during the manufacturing process. In both investigations, the main limitation found is the absence of image datasets with which to train the algorithms. However, the results obtained can be extrapolated to other components used in HVC if sufficient images of classified defects are available.