Farm in a box

An inventor in Kenya has come up with a farm kit he claims can grow enough plants and livestock to feed a family in a space the size of a small car.

The 'aquaponic' system combines growing beds with a tank for rearing edible fish or shrimps. The two systems work in harmony using minimal amounts of energy and water.

If this sounds like the stuff of science fiction, its creator assures me the idea has been around for centuries and is beguilingly simple. That said, he has little doubt about its potential to revolutionise the way food is produced in the future.

I meet Heino Dahmen in a sprawling garage on the outskirts of the port city of Mombasa. He has run this business and an adjoining shipyard on the Mtwapa Creek for 20 years, but now devotes almost all his time to a bewildering array of engineering projects.

Human waste as fuel

Dried human waste could be the next big business opportunity in Sub-Saharan Africa as well as helping to flush out the problem of poor sanitation, according to a start-up in the coastal city of Mombasa.

Waste Enterprisers believes the "faecal sludge" found in pit latrines and septic tanks could be used as industrial fuel in place of imported coal and other biofuels. 

The company's CEO, Dr Ashley Muspratt, said that dried waste has been shown to burn at least as well as coffee husks and palm nut shells in tests. Unlike these more common biofuels, there is a plentiful local supply of sewage all year round. 

"I like to talk about what we're doing as replacing [sewage] treatment plants with factories. When you talk about factories you're talking about bringing in a raw material and putting out a value-added product," Dr Muspratt said. 

A pile of dried sludge in Kampala (Moritz Gold / SANDEC)

Podcast #41: Aussie bushfires, A setback for Shell's Arctic drilling plans + Your chance to be an astronaut

 This podcast includes the following stories:

1. Bushfires engulf southern Australia
2. Beached Kulluk drilling platform proves a major headache for Shell
3. Report: Half of the food produced on Earth is wasted
4. Transocean to plead guilty over Gulf oil spill
5. Kenya's largest ivory poaching massacre
6. Lake Ellsworth team downs tools
7. Ghana bans imports of fridges
8. Record price paid for bluefin tuna in Japan
9. Wanted: Volunteers to colonise Mars

Listen to more CoolGreen episodes here