Declare: Photo voltaic-powered fridges would eradicate African meals waste

Essay by Eric Worrall

If only people like International Environment and Resource Policy Post Doc Abay Yimere would talk to the engineering department before discussing technology solutions.

Installing solar-powered refrigerators in developing countries is an effective way to reduce hunger and slow climate change

Published: Jan 20, 2023 12:36 AM AEDT

believe it or not
Postdoctoral Fellow in International Environmental and Resource Policy, Tufts University

Food losses and waste are major problems around the world. When food is wasted or spoils, economies become less productive and people go hungry.

It also harms the Earth’s climate by producing methane, a potent greenhouse gas. Food losses and waste account for 4% of global greenhouse gas emissions. If food waste were a country, it would be the third largest emitter in the world, ahead of India and behind only China and the US


Extending food cold chains to the world’s least developed countries can have a huge impact. But there is also cause for concern if it is not done in a way that does not contribute to climate change.

Existing refrigeration systems emit chlorofluorocarbons, or HCFCs, and hydrofluorocarbons, or HFCs, which are extremely potent greenhouse gases. Fossil fuel power generation to power these systems also exacerbates climate change. For these reasons, exporting traditional cold chains to developing countries is environmentally and socially unsustainable.

Instead, developing countries need cold chains that run on renewable energy and use alternative refrigerants with a lower climate impact. As a researcher specializing in sustainable development, green growth and climate change, I believe that extending cold chains in developing countries – particularly in sub-Saharan Africa – not only benefits the environment, but also offers important social benefits such as: B. the empowerment of women.

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A friend uses solar power to run his fridge – 10KW solar panels + a backup battery to run two household fridges and a freezer. The total cost for the solar panels and battery is about $10,000 for a family of four. Despite this, he has to switch to mains power a few times a year when a prolonged cloudy weather spell prevents his battery from charging.

The cost of the battery alone is a showstopper. Without the battery, my friend’s solar fridges would be next to useless. With the battery they just let him down sometimes. But how many poor Africans can afford a $10,000 family fridge? Or even a $3000 family fridge?

There is a better solution – an absorption refrigerator.

Absorption refrigerators are simple, cheap technology dating back to the 1920’s that can run on any heat source – including but not limited to solar energy. They used to be common—my grandpa had a chest-sized, kerosene-fuelled, portable absorber fridge that he kept in the back of his pickup truck for camping trips.

The following video from 1939 explains how an absorption refrigerator works.

Absorption refrigerators require no electricity and have no moving parts, although they can use electricity to provide the heat they need to operate. A fire, usually propane or kerosene, fuels a cyclical series of chemical reactions that keep the inside of the refrigerator cold.

Such refrigerators could easily be adapted to a wood burning firebox, they only need a heat source – it doesn’t matter how the heat is generated. They do not require CFCs, the cooling circuit uses ammonia, water and hydrogen – so they could be recharged on site with cheap chemicals without much effort.

Such refrigerators could be assembled by a competent welder according to a blueprint. Africa has many skilled machine welders and metalworkers, nothing is thrown away in Africa until it is truly beyond repair. As I said, they exist no moving partsthere are no expensive, hard-to-find components – just an array of gas-tight pipes and heaters.

All it takes for experienced African craftsmen is the know-how to assemble the fridge from parts they likely already have in their workshops.

Be sure to run the absorber fridge on solar power when sunlight is available – a cheap solar concentrator would suffice, you wouldn’t need expensive solar panels. A molten salt heat reservoir, like the salt in an off-peak electric powered wall heater, could potentially be used to keep the fridge running at night, or the owner could light the firebox and fuel the fridge with coal or wood after the sun goes down.

Of course, some of the absorption fridges could be adapted by owners to work with fossil fuels even if they didn’t start out that way – so maybe that rules them out as the perfect “climate solution” even if it were an incredibly cheap and accessible solution for the problem of cold food storage in Africa.

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