Initiatives to promote refrigeration technologies in the developing world

1. EcoFridges program

 

EcoFridges is a joint programme launched by the United Nations Environment Programme's United for Efficiency (U4E) and the governments of Ghana and Senegal. It aims to accelerate the switch to energy-efficient and climate-friendly refrigeration and air-conditioning solutions in West African States.

 

EcoFridges aims to provide a total of $8.4 million in funding to support the purchase of 23,600 energy-efficient and climate-friendly cooling units. The goal is to replace old equipment in Senegal and Ghana.

 

In Ghana, over 10,000 energy-efficient and climate-friendly domestic refrigerators and air conditioners will soon become widely available to replace old existing equipment by 2022.

 

2. Chill challenge

 

The Chill Challenge seeks to support affordable refrigeration technologies for off-grid households in the developing world. It is supported by Engineers Without Borders USA.

 

It recently granted initiatives to develop affordable refrigeration technologies in the developing world:

 

• A solar cooling ice machine

This device has been developed for milk cooling, and the systems were deployed in Tunisia, Kenya and Columbia. The icemaker is theoretically capable of produncing 100-120 kg of ice per day. It uses DC direct-drive vapour compression technology, working with R600a as a refrigerant (isobutane). It is powered by PV panels.

The device is developed at the University of Hohenheim in Germany.

 

• An ice maker using R717 (ammonia) as a refrigerant

In India, New Leaf is currently developing an ammonia refrigeration system to provide safe storage and cooling of perishable agricultural produce. 

The system is powered by farm waste such as straw, cow dung, biomass pellets, wood and hay, etc. It can cool up to 1,500 litres of milk or 15 tonnes of perishables goods without the need for electric grid power or diesel generator backup. 

 

• A passive cooling box

This device is about to be developed by Arup. It consists in a completely passive cooling box capable of achieving the 3°C target temperature and maintaining that temperature across several days of adverse weather conditions. The container will rely on radiative cooling materials as a cold source and phase-change materials as cold storage.

 

• An off-the-grid refrigerator working with solid-state refrigerant

The company Xergy will build a refrigerator utilising an intermittent adsorption refrigeration cycle driven by solar thermal energy. The unit will use hydrogen and metal hydride as the working pair, and employ an advanced heat exchanger design, which the company believes will result in an efficiency of 70%. The system will store hot water to provide refrigeration for “dark days” without solar input. 

 

• Cold storage battery for domestic refrigeration

The device is tested at the Purdue University. It will valuate the use of heat from clay or brick cookstoves to drive an intermittent sorption refrigerator, which requires no electricity to operate. The sorption refrigeration device is referred to as a cold storage battery because the generated refrigerant does not need to be immediately discharged, but can instead be stored and expanded later to provide cooling on demand.

 

• Combined heating and cooling for agricultural applications

The team of Purdue University proposes to build a system that generates 100-150 kg of ice per day, using a vapor compression cycle with R290 as the refrigerant and solar PV as an energy source. This research will examine the potential for of using a combined heating and cooling vapor compression system to produce ice and to dry crops.

 

• Affordable Decentralized Off-grid Icemaking

The CEP Laboratory at Imperial College London and Solar Polar have been developing a thermally powered technology, referred to as Diffusion Absorption Refrigeration (DAR), which can be easily integrated with low-cost solar thermal collectors or that utilise waste heat to provide cooling. The CEP team proposes to design and demonstrate an innovative yet affordable icemaker based on DAR technology. Robust and simple to use, the icemaker will use hot water from solar-thermal collectors, specifically aimed at developing, remote or off-grid communities.