Sea Water Analysis

The seawater is a solution of salts that, usually, has a constant composition. It is dissolved in variable amounts of water. The analysis of ions in the Egyptian Mediterranean Sea coast are listed in Table 3 with typical standard seawater analysis according to [21]. All elements are dissolved in seawater and are found as ions – electrically charged atoms or groups of atoms.

Saline water solution (composed from pure water and seawater) is used as electrolyte with concentrations of 25%, 37.5%, 50%, 70%, 85% and 100% of seawater.

Figure 3 shows the hydrogen production rate changes with saline water concentrations at different input voltages. It illustrates that the increase in the concentration of saline water, the higher the hydrogen gas flow

5 for each used electrolyte. The variation in the efficiency of the system with electrolyte replace is plotted in Fig. 9 as a function of local time. Higher efficiency is for the system occupying a KOH solution followed by seawater followed by Nile water. In a time domain, the efficiency is starting high in the morning, and decreasing to a minimum value at the solar noon and then come back to increase. The higher solar intensity accompanied with higher surface temperatures at the noon are the main factors that contribute in lowering system efficiency to the minimum[14, 18]. The variation of module surface temperature with local time is plotted in Fig. 10. The PV/Hydrogen system with KOH solution reaches a minimum efficiency of 1% at solar noon while it attains about 8% at both extremes. Excluding the relatively small periods of beginning and the end of the experiment, the efficiency of the system occupying both sea and Nile water gives a nearly constants efficiencies of 0.13 % and 0.005 % along the experimentation

• It needs about seven units of PV/Hydrogen unit occupying seawater as an electrolyte to produce same amount of pure hydrogen from a single unit uses KOH solution as an electrolyte. While it requires about 153 units when Nile River is the electrolyte.

• Sea water is recommended over the water of Nile River as a good replacement for KOH/water solution electrolyte. Taking into consideration that seawater is abundant and free of charge and, KOH solution is factory made with a specified cost, the hydrogen production using PV/Hydrogen unit with seawater as an electrolyte will be effective operation.

• Seawater and Nile water give a relatively constant efficiency over the wide range of light time, incident solar radiation and hydrogen production rate.

• KOH solution gives higher efficiency rate than seawater followed by Nile water

It is recommended for the future work the following;

• The research is to be done in different days around the