Africa lacks toilets. The West maintains an expensive sewer system that wastes the human waste. The two problems have found their solution in Accra, Ghana, where a company has developed toilets that will put human waste to good use. “Open defecation is a big problem here in Africa because it spreads disease”, explains Kweku Anno, founder of BioFil. “But in developed countries toilets are a nutrient dump. Nutrients are sent to the sewer. There’s no reason that human waste should be transported away at great expense when it can be recycled on site.”

BioFil toilets save that human waste – and reuse it as fertilizer. “Rather than nutrients ending up in oceans and rivers, they can end up as food”, he explains as he shows Metro around his production facility. “The waste from the toilet goes directly to a digester, where the solids are completely broken down and the nutrients filtered out with the liquids, to be used as fertilizer. The food we eat can become the next food.”

BioFil has already installed 4,000 toilets across West Africa. “We have four in our house!” adds Anno’s wife, Lydia. “They can be used in the West as well”, explains Anno. “You can have the digester on your balcony or even in your living room. “And something that’s really important in a green economy is that it can recover nutrients, replacing artificial fertilizers.” According to Linus Dagerskog, Research Associate at the Stockholm Environment Institute, the toilet is a promising concept: “It uses minimal amounts of water, it reuses the water used to clean one’s hands, and it filters the waste above ground, which protects the ground water”, he says. “It could even work in colder countries if its filter can be isolated from freezing outdoor temperatures.” At BioFil’s factory in Accra, I put my nose in both the toilet and the digester. They don’t smell.