## 3 Results
### Current Status, Challenges and Future Developments
#### 3.2.4 Renewable Hydrogen End-Uses  
According to the Global Hydrogen Review 2024 [133], the end-uses of renewable hydrogen can be classified into industry and buildings, mobility, and power generation. As shown in the report, the level of development in each category is different. The categories closest to the market with a higher Technology Readiness Level (TRL) are those corresponding to mobility (Hydrogen Refueling Stations (HRS) and Fuel Cell Vehicles (FCVEH)), buildings (Proton Exchange Membrane Fuel Cell (PEMFC) and Solid Oxide Fuel Cell (SOFC) ogeneration) and power generation (High-Temperature Fuel Cell (FC)). One of the barriers detected in the Global Hydrogen Review 2024 is the level of technological development of each component of the FCs, which is why a separate category has been included in which geospatial techniques can be included. Table 8 summarizes the main applications and main challenges of geospatial techniques in the different categories into which hydrogen end uses can be classified according to the systematic literature review performed. The application where geospatial techniques stand out is mobility. It is considered that this is because it is the application with the closest to market [133], since there are different car brands that have FCVEH models in their catalogs [166]. Geospatial techniques stand out in the search for and opening of new markets, through the optimization of HRS site selection. [PERSON], [PERSON] et al. [142] perform a GIS-MCDM to analyze the \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Application** & **Ref.** & \begin{tabular}{c} **Main Geospatial** \\ **Techniques** \\ \end{tabular} & \begin{tabular}{c} **Primary Uses of the** \\ **Geospatial Technique** \\ \end{tabular} & \begin{tabular}{c} **Challenges** \\ \end{tabular} \\ \hline Mobility & [134; 135; 136; 137; 138; 139; 140; 141; 142; 143; 144; 145; 146; 147; 148; 149; 150; 151; 152; 153; 154; 155; 156; 157] & GIS and IoT & \begin{tabular}{c} Multi-source database \\ integration \\ Visualization results \\ Real-time data acquisition \\ Environmental analysis \\ \end{tabular} & Data reliability; lack of \begin{tabular}{c} geolocalized data \\ \end{tabular} \\ \hline \begin{tabular}{c} Industry and \\ Buildings \\ \end{tabular} & [158; 159; 160] & GIS & \begin{tabular}{c} Multi-source database \\ integration \\ Visualization results \\ Optimization and \\ cluster algorithm \\ \end{tabular} & Lack of open database; Computational time \\ \hline Power generation & [161; 55; 162] & GIS and DT (IoT) & \begin{tabular}{c} Monitorization and \\ precise control PEMFC \\ Techno-economic analysis \\ \end{tabular} & Low resolution \\ \hline Component & [163; 164; 165] & CV and IRT & \
\begin{tabular}{c} Detection of membrane \\ manufacturing defects \\ Thermal analysis PEMFC \\ \end{tabular} &
\begin{tabular}{c} Integration in the \\ manufacturing process \\ Automatic detection \\ deep learning \\ algorithms \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Summary geospatial techniques applied to renewable hydrogen end-uses. suitability of incorporating wind-generated renewable hydrogen into existing conventional refueling stations in the Netherlands. One of the sources used is OpenStreetMap (OSM), which introduces uncertainty in the reliability of the data as OSM data are entered and validated by individual users and are not managed by relevant institutions. GIS techniques can also be employed for the comparison of different HRS implementation scenarios. [PERSON], [PERSON] et al. [135] use GIS to implement geospatial models including dynamic data for the calculation of energy estimation on long-distance truck routes in Europe. The research analyzes only major roads, as lower ranked roads are not included in the national strategic reports where future scenarios to 2050 are evaluated. In the same line of research, [PERSON], [PERSON] et al.