For millions of Nigerians in rural Kaduna state, a trip to an outdoor food market provides cheap and ready access to the staples of a traditional diet. In a normal week, dozens of wicker baskets overflow with ripe tomatoes, an essential ingredient in the rich stews favoured by locals.

Yet over the summer, market-goers were dismayed by the spiralling costs of a fruit that has come to be seen as a national necessity. After a moth epidemic ravaged some 80% of the region’s tomato farms in May, forcing the price of a basket from $1.20 to more than $40, Kaduna’s authorities were forced to declare a state of emergency.

Kaduna’s ‘tomato emergency’ is part of a national dip in food production that is concerning Nigeria’s food security experts. In the north-east, production in large parts of the country has been all but abandoned in the face of continued attacks by Boko Haram militants, putting millions at risk of famine.

Yet even in areas where food production remains strong, poor handling, storage and delivery methods mean that much of Nigeria’s food is spoiled before reaching those in need. In a bid to minimise post-harvest losses – which government estimates could be higher than 50% folr some fruits and vegetables – businesses are beginning to develop new technologies to assist farmers. For one entrepreneur, the causes of post-harvest losses are obvious.

“Most of the spoilage starts on the farms because farmers don’t receive visits from delivery trucks every day,” says Nnaemeka Ikegwuonu, chief executive of Cold Hubs. “Sometimes it takes 3 to 4 days for trucks to come to the farm. So these farmers keep the food in a shed or try and cover it, and by the time the truck comes in the food is already spoiled. The trucks take a long trip to the market, and spoilage accelerates.”

That’s a problem common to farms across the continent. In 2011, the UN World Food Programme estimated that annual food losses in Sub-Saharan Africa exceeded 30% of total crop production and cost farmers some $4bn in value every year.

Cold Hubs offers a simple solution. The firm installs walk-in refrigeration units near both farms and markets in a bid to preserve valuable crops in the crucial period before they reach consumers. Tomatoes which would have rotted near the vine are swiftly dispatched to a nearby unit, where farmers are charged around 50¢ per crate per day to cool the produce.

It’s a pay-as- you-go model which allows farmers to dodge pricey storage agreements that tie them to excessive payments regardless of production.

Perhaps even more convenient – in a country where 95m are estimated to have no access to electricity – is that the refrigeration hubs are entirely solar powered.

Whether the units are installed in remote rural villages or bustling urban markets, the power of the sun can be harvested to save, rather than spoil, produce. It’s an affordable and eco-friendly model freed of expensive infrastructure that the company believes could be quickly rolled out across the continent, beginning with further expansion in Nigeria and a potential franchising scheme in Kenya.

“In five years we want to have 1000 installed in Nigeria, and in the future, there could be 1 million units all over Africa,” says Ikegwuonu.

“We’re very ambitious because there’s lots of market opportunity – you can use them in schools, hospitals, airports – anywhere you need to store food.”

For the hawkers and worried consumers of the markets in Kaduna, it may be the first step to ensuring that 2016’s tomato emergency remains little more than an unpleasant memory.