New technology that uses seawater to create a renewable alternative to air conditioning has received a boost from a new study led by the International Institute of Applied System Analysis (IIASA)—although the research may have missed the biggest problem with the technology.
Published in the journal Energy Efficiency, the study set out to determine the economic pros, and some of the cons, of seawater air conditioning (SWAC), a renewable technology that could hold promise as an alternative to the standard, emissions-heavy air conditioners that hum in their millions around the world, reports Inhabitat.
“The study looks at the possibility of pumping deep seawater from 700 to 1,200 metres deep at the temperature of 3° to 5°C to the coast, where it exchanges heat within a cooling system,” Inhabitat explains. It found that “just one cubic metre of seawater could provide cooling energy equivalent to that provided by 21 wind turbines.”
While building SWAC systems “would require heavy initial investments,” the IIASA researchers said operating costs would be lower than conventional systems, delivering savings as high as 77% in some coastal jurisdictions and islands.
In one version of the SWAC approach defined as “high-velocity,” cooling loads can be expanded “modularly through smaller additional capital costs” once the main system is in place, said lead author Julian Hunt. If it ever becomes commercially available, the technology could be a particular boon to big power users such as data centres, airports, hotels, and resorts.
But that availability is still some ways away. The researchers acknowledged risks in the technology that have yet to be addressed, including the need to pump the incoming warm water deep enough to prevent algae blooms, and for the systems “to be handled and monitored carefully to preserve marine life and not disrupt the ecosystems.”
The study also seems not to have addressed the issue of thermal pollution, at a time when additional warming is the very last thing anyone should be considering for the world’s oceans. In 2014, after looking into SWAC and similar systems using lake water, the Institute of Earth Sciences at Hebrew University of Jerusalem flagged ocean heating as a concern that had not yet been explored in depth. [Or at depth. Because, y’know, we’ll never turn down a terrible pun—Ed.]