Solar Energy has achieved full international recognition as a primary source of sustainable energy. In connection, the King Abdullah City for Atomic & Renewable Energy (KA CARE) has formally included Solar Energy as a second line of energy source for power generation and desalination in the Kingdom.
In general, the peak electricity consumption during the day-time (arising mainly from the operation of air-conditioning systems) can be directly met by using solar power generation, without the need to store any excess energy.
However, in the case of Solar Energy application for Seawater Desalination systems, the following considerations are necessary:
- Quantum of Available Solar Energy: The capacity for the Proposed Desalination Plant has to be designed to meet daily requirement, based on the total quantum of solar energy that can be economically harnessed.
- Product Water Storage: The Product Water storage tanks can also be used as a means to store a reasonably quantum of energy in water form.
- Most economical/highest energy efficiency Desalination System: As the primary constraint in almost all cases is the limited availability of Solar Energy, for instance 2000kWh/m2/year of solar energy, the selection of a Desalination System needs to be made based on lowest energy consumption per unit production, in order to achieve the highest possible production per unit energy.
Following the above, a Solar Desalination System shall be designed on basis of highest efficiency in order to meet future sustainability. In practice, the Concentrated Solar Power (CSP) system is preferred over Photo-Voltaic (PV) due to the ease in energy storage in molten salt compared to batteries.
The high Gain Output Ratio (GOR) or high Performance Ratio (PR) of the Tri-hybrid desalination system is ideal to be paired with CSP system for maximum efficiency.
Sasakura Engineering Co., Ltd. is currently conducting research in the application of CSP system for Desalination systems based on Thermo Electric Steam Generator (TESG) technology. This technology generates both electric power and steam by using thermoelectric element.
Figure -3: Concept of Tri-hybrid Desalination System using Thermo Electric Steam Generator (TESG) Technology