Researchers test seawater air conditioning as a renewable cooling alternative
A new study led by the International Institute of Applied System Analysis (IIASA) indicates that using seawater air conditioning is a greener alternative to conventional AC and could reduce cooling costs significantly. The study, which was published in the journal Energy Efficiency, was conducted to determine the pros and cons of seawater air conditioning (SWAC). The researchers behind the study say that there is a need to find renewable air conditioning alternatives to conventional options as global warming worsens.
The study looks at the possibility of pumping deep seawater from 700-1,200 meters deep at the temperature of 3° to 5° Celsius to the coast, where it exchanges heat within a cooling system. The study now shows that just one cubic meter of seawater could provide cooling energy equivalent to that provided by 21 wind turbines. To better understand the pros and cons of SWAC systems, the researchers developed a computational model used to estimate the cost of cooling around the world. The model was also used in determining the possibility of using this approach in all parts of the world.
The results showed that while it is possible to use SWAC systems in many parts of the world, they would require heavy initial investments. But in comparison to conventional air conditioning, the research determined that SWAC would offer lower operational costs. Further, the study found that in some coastal cities and islands, the cooling costs would drop as much as 77% of the normal cooling costs via conventional AC.
According to the study, the primary consumers of this technology would be airports, hotels and resorts among other establishments that consume high quantities of power. According to Julian Hunt, lead author of the study, SWAC systems have the potential of increasing efficiency over time.
“We call this approach ‘High-Velocity Seawater Air-conditioning’,” Hunt explained. “This design configuration allows such projects to be built with an initial cooling load and expand the cooling load modularly through smaller additional capital costs.”
While the study has established many positives of using seawater air conditioning, there are challenges that were identified. The systems would need to be handled and monitored carefully to preserve marine life and not disrupt the ecosystems.
Hunt said, “While it does have its challenges, seawater air-conditioning is an innovative and sustainable technology that has great potential for expanding into a benchmark system for cooling in tropical locations close to the deep sea and will help fulfill our cooling needs in a warming world.”