Solar powered tent keeps agroproduce cool

 

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University of Nairobi student Emmanuel Amwoka (in white polo tshirt) zips the Wakati tent fridge after packing capsicums. Looking on is a colleague. The solar powered tent keeps fruits and vegetables fresh for more than seven days. Photo courtesy.

The University of Nairobi students have come up with a cheap solar powered tent to help farmers keep fruits and vegetables fresh for more than five days after harvest.

Keeping the produce fresh for long extends the marketing time, therefore, averting post harvest losses.

The equipment, which is borrowed on the Tanzania’s Wakati tent fridge, only requires solar power to keep fruits and vegetables fresh for a week or so.

Upper Kabete Campus student Emmanuel Amwoka said tests have proven that fresh vegetables and fruits are marketable after five and seven days respectively when stored in the tent.

The one metre by one and half metre tent can host up to 300kg of tomatoes.

The canvas tent has a solar powered fan at one corner. The fan is placed in a cuplike water reservoir. As it rotates, it picks the water into mist droplets, which are distributed in the tent by air currents.

“When a moisture concentration of 80 per cent is achieved, the surface of the fruits and vegetables remain fresh because of there is no net loss of water. Keeping any produce fresh for long gives farmers more time to sell,” Amwoka said.

It is not only a facility for farmers, but also sellers of fresh produce.

Living things naturally lose water to the atmosphere when the humidity concentration on the outside is low. The same happens on dry windy days.

But the microclimate created in the tent decelerates the loss of water, therefore, keeping the skin firm for long.

Besides the cooling ability, the tent also reduces the speed of ripening of fruits, with capsicums remaining fresh for up to 10 days.

“The fan oxidizes oxygen in water into ozone (tri-oxygen). The three oxygen ‘atomed’ molecule fights off ethylene gas from the tent through a series of chemical reactions. Reduced ethylene is reduced ripening,” Amwaka said during the 2016 University of Nairobi tech expo.

Ethylene gas is emitted by fruits. It accelerates ripening of fruits.

Fruits and vegetables, just like other living things, lose water to the surrounding when the air around them is dry or less concentrated with humidity.

Good refrigerators and other coolers cost more than Sh20,000. In addition to the initial cost, maintenance costs and power bills are prohibitive to average small-scale farmers, who may also be away from the national electricity grid.

These, among other attributes, make the Wakati tent cooler an appropriate tool for rural farmers and agro-traders.

The entire kit is set to cost about Sh10,000.

Amwoka can be reached on +254708837798