[Haichuan New Energy] Generates electricity using local concentration salinity gradients
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Online reports: Recently, Professor Zhou Jun from Huazhong University of Science and Technology and his colleagues proposed a new approach for making multiple uses of solar energy to simultaneously desalinate seawater and generate power through salinity difference: utilizing the photothermal effect of solar energy to heat the surface water, thereby causing it to evaporate rapidly and enabling seawater desalination； At the same time, the rapid evaporation of water leads to an increase in the salt concentration of the surface seawater, creating a large local concentration difference with the deeper seawater, which in turn enables further salt-gradient power generation.
【Summary of Achievements】 Recently, Professor Zhou Jun from Huazhong University of Science and Technology (corresponding author) and his colleagues proposed a new approach for the multi-purpose utilization of solar energy for both seawater desalination and salinity gradient power generation: utilizing the photothermal effect of solar energy to heat the surface water, thereby causing it to evaporate rapidly and enabling seawater desalination； At the same time, the rapid evaporation of water leads to an increase in the salt concentration of the surface seawater, creating a large local concentration difference with the deeper seawater, which in turn enables further salt-gradient power generation. They confirmed that under standard sunlight, the theoretical salinity gradient energy for this area can reach 12.5 W m?2. On this basis, they designed a composite system for seawater desalination and salinity gradient power generation based on carbon nanotube (CNT)-modified filter paper and commercial Nafion membranes, achieving a photothermal conversion efficiency of ~75% for seawater desalination under standard sunlight, while simultaneously generating an electrical power output of 1 W m?2. The study also demonstrated the system’s potential to simultaneously perform solar desalination of seawater and salinity gradient power generation under natural light, offering new strategies for the efficient utilization of blue energy. The relevant findings were published in Energy & Environmental Science under the title “Solar-driven simultaneous steam production and electricity generation from salinity”. The first authors of this paper are Yang Peihua and Liu Kang.
The idea of generating power through oceanic evaporation concentration differences has existed for a long time; Israeli researchers plan to use the difference in sea levels between the four seas and the Mediterranean to generate electricity, following this same concept, with even greater feasibility.
Theoretically feasible, suitable for large-scale engineering implementation, economically reasonable, but challenging.
The idea is good; succeeding in implementing one item is enough.
Every success begins with an idea