## Appendix A Locations Selection, System Design, Dimensioning, and Components
### Technological and Economic Characterization of System Components in Two Scenarios  
Table 12 lists the specific energy consumption and production (SEC and SEP) (kWh/kg H\({}_{2}\)) in the Near Future and Mid Century scenarios for the different energy conversion processes, from rainwater collection to hydrogen production, fueling, and reconversion to electricity. Alkaline water electrolysis technology is chosen as, at the moment, it is cheaper than Proton Exchange Membrane (PEM) electrolysis technology [136; 244]. The electrolyzer is coupled directly to the direct current renewable energy source, so there is no AC/DC conversion needed at the electrolyzer [245]. Current state-of-the-art alkaline electrolysis technology can respond sufficiently fast [136; 246; 247] to short-term solar and wind power fluctuations [248; 249; 250; 251; 252; 253; 254]. The alkaline water electrolysis part-load efficiency curve is used from [255], and its maximum efficiency point (higher heating value (HHV)-based) is 88.8% [256; 257; 258] for the Near Future and 92.6% for the Mid Century scenario [258; 259]. SEC for hydrogen purification is, respectively, 1.3 and 1.1 kWh/kg H\({}_{2}\) in the Near Future and the Mid Centuryscenario [260; 261]. After purification, drying, and oxygen removal, the hydrogen meets the purity required for FCEVs [262] at a pressure of 15 bar and 30 bar in, respectively, the Near Future and the Mid Century scenario [136; 256; 257; 259]. Compression SEC for all compressors (S6, W6, HFS1, and SHS2) in the Near Future scenario is in the range of 0.5-3.1 kWh\({}_{\text{e}}\)/kg H\({}_{2}\), and in the Mid Century scenario 0.4-2.5 kWh\({}_{\text{e}}\)/kg H\({}_{2}\)[115; 263; 264; 265; 266]. The reduction in SEC in the Mid Century scenario is due to the increase in isentropic efficiency from 60% to 80% [263] and, for compressors S6 and W6, also the higher hydrogen output pressure of the electrolyzers. The compressor at the wind park (W6) has an outlet pressure of 180 bar, the maximum SHS operating pressure [104], which is assumed to be constant in this study. The operating pressure range of hydrogen tube trailers in both scenarios is 30-500 bar with an effective storage capacity of 1014 kg H\({}_{2}\)[136; 267; 268; 269]. By applying a smart consolidation strategy for emptying and filling tube trailers at the SHS [263; 264; 270; 271], the net electricity consumption is simplified as compressing hydrogen from 180 bar to 500 bar (SHS2). The electricity consumption of compressor S8 is modeled as the compression of hydrogen from the hydrogen purification output pressure of 30 bar to 500 bar. The combined compressor capacity at the HFS (HFS1) is the largest of all compressors and is modeled with a variable inlet pressure of 30-500 bar (emptying the tube trailers) and fixed outlet pressure of 875 bar of the storage (HFS2). Hydrogen cooling SEC for fueling at 700 bar is 0.20 and 0.15 kWh\({}_{\text{e}}\)/kg H\({}_{2}\) in, respectively, the Near Future and the Mid Century scenario [177; 178], and is assumed to be constant over the entire operating range of the chiller. In this study, no reduction in specific electricity consumption is foreseen in the Mid Century scenario for reverse osmosis [272; 273; 274]. The specific energy production SEP by the FCEV is, respectively, 20.3 and 23.6 kWh\({}_{\text{e}}\)/kg H\({}_{2}\) in the Near Future and the Mid Century scenario. These values correspond to a tank-to-grid efficiency, \(\eta_{\text{TTTG}}\), [37] (analogous to tank-to-wheel, \(\eta_{\text{TTTW}}\), efficiency when driving) of, respectively, 51.5% and 60% (HHV) [275; 276]. Furthermore, it is assumed that the SEC and SEP of the conversion processes are location independent.