New technology could make fridges cheaper and more eco-friendly

A novel use of technology could make refrigerators cheaper and more environmentally friendly, according to a report.

Domestic refrigerators and freezers consumed close to 4% of global electricity in 2019, according to one estimate, so an innovation that significantly reduces their power usage would not be insignificant.

Research conducted by Huazhong University of Science and Technology has shown that thermogalvanic technology has promising potential as a cooling mechanism and could be a sustainable alternative to the vapour compression technology now used in most fridges.

“Thermogalvanic cooling with a potential low carbon footprint is an environment-friendly technology, which will promote carbon neutrality if their usage became widespread,” said the study’s senior author Jiangjiang Duan.

The study also found that the technology could be expanded across various applications, from wearable cooling devices to industrial-grade scenarios.

“Thermogalvanic technology is on its way to our lives, either in the form of clean electricity or low-power cooling, and both research and commercial communities should be paying attention,” said Duan.

Thermogalvanic cells use the heat produced by reversible chemical reactions to create electrical power. Researchers have found that thermogalvanic hydrogel, for example, could be used to keep a mobile phone battery cool while turning the waste heat into electricity.

In theory reversing this process enables the generation of cooling power, but previous studies have shown this effect to have limited potential. By optimising the chemicals used in the process, researchers found that they were able to improve the hydrogalvanic cell’s cooling power by 70%.

Electricity used to power refrigerators combined with gas leakages from fridges and freezers into the atmosphere make them a significant source of greenhouse emissions. Fifty per cent of UK food refrigeration emissions are from electrical power, with 37% of UK food refrigeration electrical emissions from domestic refrigerators, according to a study published by the International Journal of Refrigeration.

Future research conducted by this team will include optimising the system’s design and investigating other potential commercial use.

“Though our advanced electrolyte is commercially viable, further efforts in the system-level design, scalability, and stability are required to promote the practical application of this technology,” said Duan.

“In the future, we aim to continuously improve the thermogalvanic cooling performance by exploring novel mechanisms and advanced materials. We are also attempting to develop diverse refrigerator prototypes towards potential application scenarios and are seeking to collaborate with companies to promote commercialisation of thermogalvanic technologies.”