The Community Cooker, a Waste to Energy Solution for Developing Urban Settlement

An innovative system transforms rubbish into what urban slum communities need most. The Community Cooker is an integrated waste-management solution, where slum residents can exchange their trash for purified water, cooking time, or even hot showers at a single facility. Under the motto “trash to cash – a rubbish-free world,” the project saves people money and resources, and helps clean up poor Nairobi communities.

Fast facts:

3 Community Cookers completed
Cookers have combustion efficiency of 99 per cent
Each cooker could save the calorific heat equivalent of burning around 3,000 mature trees over one year
Project has received wide recognition, including winning two awards

The problem

More than 80 per cent of Kenya’s urban dwellers – many of whom live in poor, informal settlements – use charcoal made from wood as their primary source of energy. Their heavy dependence on wood for fuel has contributed to the rapid decline of Kenya’s forests. This has negative effects on the climate, local wildlife, water sources, and forest-dwellers.

The solution

This project transforms rubbish into energy with the help of a high-temperature industrial cooker. Workers at the facility sort waste, including recycling valuable materials, and incinerate the rest. The cooker, which took several years and numerous redesigns to develop, uses natural airflow, discarded sump oil, and water to catalyze heating to temperatures to more than 800 degrees Celsius. Heat from the cooker, which is constructed in a communal, publicly accessible facility, can be used to boil water, brew tea, cook traditional foods, and bake cakes, among many other purposes.

At the Community Cooker in Kibera – Africa’s largest slum – residents exchange waste for tokens they can use for time to cook on the stove, heat/purify water, or even to bathe.

Helping the planet

The cooker’s high combustion efficiency means far fewer pollutants are released than through open-air burning. The pollution levels fall within the limits established by the United States EPA and World Bank IFC guidelines. Land and water pollution is further decreased by proper disposal, for example, of sump oil. Use of this alternative source of energy reduces demand for coal, thus preventing deforestation and further greenhouse gas emissions. Methane emissions from uncontrolled decomposition of organic matter is also decreased, as the facility composts organic material for use in sack gardening.

Helping people

The Community Cookers provide slums with something they have never had before: affordable heat for cooking food and boiling water on a regular basis. People who use it save money on coal, and benefit from inhaling less noxious particles from inefficient cook stoves. Reducing trash creates a cleaner and more hygienic urban environment, while the facility also creates jobs. The cooker reduces expenses by encouraging users to share amenities, and also acts as a social hub that encourages peaceful communication.

Spillover effect

The hope is to replicate similar projects, both regionally and internationally. The model would work in any environment that has a high demand for heat energy and access to sufficient volumes of rubbish on a daily basis.

The project continues to improve the cooker’s design. Its implementation is also being explored in schools, clinics, landfills, and refugee camps. The project is also investigating further “add-ons,” which could include distilling water, smelting soft metal, baking clay products, drying tea leaves, generating electricity, and a bio-digester system that could replace pit latrines and distribute high-nutrient gray water for small-scale farming in slums.