Energy production through residual heat harvesting from domestic/commercial fridges using nanostructured thermoelectric modules

Refrigerated food product merchants want their products to be well lit and attractive to customers on a 24 h daily basis. However, provide continuous illumination is both unappealing and inefficient. Refrigeration systems are considered as high energy consumption appliances. It is estimated that in those systems energy losses in the form of heat are more significant in the gas compressor and condenser than in the rest of the system, which reach up to 78%. Furthermore, if one takes into account that it represents a free heat source because it is a by-product of compressed gas and is covered by the cost of operating the gas compressor then compressor and condenser are an alternative heat source for the recovery of residual thermal energy, and convert it into electricity in a clean way for further purpose. In the present work, as proof of concept, a thermoelectric converter prototype for the selfpowering of refrigerator's lighting system has been developed. System is based on enhanced performance nanostructured thermoelectric modules which present an increment of around 35% on the maximum output power in comparison to a reference device commercially available. Amazingly, the thermoelectric converter is capable to efficiently harvest heat from fridge condenser system, and power up continuously fridge lighting system itself. Hence, taking into consideration the global fridge volume in use is estimated to increase up to 9.5 billion by 2050, present proposal could have significant impacts and benefits to society, both energy and environmental context.