The WEA scheme has several patterns, such as employing concentrated solar power (CSP) for electricity generation, multi-effect distillation (MED) for desalination, etc. The pattern of the WEA scheme analyzed in this study is as follows (the whole picture is in Fig. ). PV is assumed as an electricity generation method, inexpensive at a large scale in arid/semi-arid regions recently. The PV electricity is used to desalinate seawater via reverse osmosis (RO), the most energy-efficient way currently. The desalinated water is then used to produce hydrogen via water electrolysis using PV electricity. The alkaline water electrolysis is employed, commercially available, and suitable for large-scale production. Nitrogen is separated from the air using the cryogenic separation method, appropriate for large scale. The obtained hydrogen and nitrogen are used to synthesize ammonia by the Haber-Bosch process, which is also commercialized and ideal for large-scale production.