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This is a community that relies on green beans for their income.
Buying energy is very expensive.
So they must have low energy solutions in their farming.
They grow tonnes of beans a year,
and when the beans are picked they are a bit warm.
We have to get the temperature down.
We have to keep them cool otherwise they will deteriorate
And that is not good.
We don't have fridges but we have charcoal coolers.
They don't use any electricity at all.
We simply put the crates of beans inside where the temperature is much lower.
So how does this charcoal cooler work? Let me show you what it's made of.
The walls are a wooden frame packed with charcoal,
like you use for barbecue, held in place by net.
All four walls and the door are made the same.
Under the roof, above the wall, there's a pipe with running water and tiny holes
where water trickles down gradually through the charcoal.
And this is the clever bit.
As the water evaporates into this warm air it cools the temperature inside.
Just as water cools you on a warm day.
It's practical. It's affordable and it's effective. It's brilliant.
It uses hardly any energy at all. Another green technology from the African field.