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Ecological cookers PDF Print E-mail

What are ecological cookers?

Ecological cookers combine renewable energy with appropriate technology to conserve the economic, natural and human resources involved in food preparation.

Appropriate technology can be defined as “technology that works in a low-cost, effective manner that local people can manage and control.” The term appropriate technology is often used to refer to practical, simple 'things' - such as tools, instruments, or machines - that people can make, use, and repair themselves using local resources.


Solar cookers

Solar cookerComponents and Operation

Our solar cookers are wooden boxes with one or more reflective covers and an inclined double glazed window on hinges. Easy to build with inexpensive materials, they can reach temperatures between 120°c and 160°c, which is sufficient for cooking nearly all of the foods consumed in Bolivia.

Concentration of the Sun’s Rays: The aluminium sides of the cooker concentrate the energy gathered by the external reflectors.

Absorption of Radiant Heat: The base of the metal inside box of the cooker is painted black to absorb heat that in turn radiates back to the food being cooked.

Heat Retention: The glass lid of the cooker should be closed to trap the heat and create a greenhouse effect.

The sun’s radiant energy passes through the glass and is both absorbed and reflected by the various materials to focus heat on the food for the most efficient cooking process. The solar cooker is also filled with insulation that considerably reduces the loss of energy.

Placement of the Solar Cooker

Solar cooker placement

How to Cook

The solar cooker allows families to cook as they would with their traditional method, and can also be used to pasteurize water. Cooking time usually takes between 2-4 hours depending on both the type of meal and the intensity of the sun. Since cooking temperatures are low, food does not need to be stirred during the cooking process and meals can be left to cook unattended like a crock-pot. As supervision is not required, more time is created for other activities. This style of cooking also retains more flavour, and consequently the need for seasoning is reduced.


Rocket stove

Rocket stoves

The rocket stove is a popular alternative to the solar cooker and can be used when there is no sun.This highly efficient wood burning stove requires only 25-30% of the fuel consumed by a conventional stove, and converts 42% of its total potential energy into thermal energy (or actual energy used). For comparison, an open fire only converts roughly 10% of that energy.

The rocket stove’s construction has been designed to substantially reduce the harmful pollution normally emitted from an open fire. It removes 95% of the noxious particles from the home due to efficient combustion of fuel and the high chimney through which gas emissions are released.