Improved Cooking Stove (ICS)

December 2015

Biomass is still the only available energy source for 2.7 billion people in the world. Over 80% of households across sub-Saharan Africa rely on biomass as their primary energy source, mostly for cooking and heating. In South Africa, 54% of the 2.4 million rural households across South Africa have use wood as their main source of energy. In some areas all natural trees will be depleted if present rate of wood use continues.

Inefficient biomass cookstoves emit smoke containing carbon monoxide (CO) and particulate matter (PM), which cause respiratory diseases.

To address this global problem, there has been a large number of improved cook stove projects in many parts of the world.

In 2010, the Nova Institute was contracted by ICCO (Kerk in Actie) to find the most suitable way to reduce wood use in one rural community, Molati near Letsitele. The main outcome of this contract was that Nova should provide an improved domestic energy solution that can be implemented and taken to scale in rural and urban communities.

An improved cooking stove

To date, research in the ICS Project has shown that the following four conditions can be improved by this initiative: inefficient use of domestic energy sources, depletion of natural resources, health (indoor air pollution, burning accidents and accidents that occur during wood collection) and poor living conditions related to low income and unemployment.

In designing ways to improve the quality of life of households, we have to understand the way in which a household would function when a given solution has become part of it. Even more importantly: the residents that we work with must begin to "see" the idea as a possibility for themselves, and begin to design ways in which this idea could work in their context. When that happens, it is an indication to us that we are on the right track. In the early phases of the design we began with a concept rather than an actual design. The concept is formed in our own minds through practice research and in-depth interviews with residents and researchers from various disciplines, both in Nova and those in our wider networks.

In the rural community, where the three-stone fire is mainly used, through our joint discussions it was concluded that the logical next step would be to develop an improved cooking stove. However, our technical research showed that solutions sought outside the technical, monetary and spatial constrains of the rural community, were favorable but could not sustainably be implemented in the rural community.

After surveying the existing cook stove projects, Nova took six stoves that are representative of the most important available models, and asked a group of about twenty residents of Molati to use and evaluate the stoves. None of the stoves complied with their requirements. The group then started to think of the possibility that they can build a stove for themselves according to their own requirements, using materials that are locally available (e.g. kraalmis, clay, salt, water, etc.). We did so together, from our part providing technical guidance. Initially, five different prototypes of the locally built stove were implemented in households to be tested and developed towards a final prototype. The stove can be seen in the photo above.

The bricks made by the community are used to make the improved cooking stoves.

This photo illustrates the first successful bricks being made by the local rural community. The bricks and the materials used to make the bricks are then used to construct the improved cooking stove. Once the formation of the bricks has been laid out, the whole structure is plastered using the same mixture of clay and cow dung used to produce the bricks.

The sketch below illustrates the finalized design that was drawn up after approximately one year's evaluation of different stove designs. This specific design was found to be performing satisfactorily according to the requirements mentioned above. After the finalization of the design the team installed 40 stoves in the focus community in order to evaluate the extent to which the stove would be integrated into the everyday cooking practice of the local community. After being in use of the household for roughly 6 months the main problem that we experienced was that the dimensions of the inlet and outlet of the stove tended to mutate after each new layer of plaster were added to the stove for maintenance.

The sketch below illustrates the finalized design that was drawn up after evaluation

This fact carried the potential to compromise the stove's combustion efficiency and therefore could not be overlooked. In order to deal with this problem we concentrated on the design and development of a standardized combustion chamber. We approached specialists in the refractory cement industry to assist in the development of this combustion chamber to ensure its durability, insulation and cost-effectiveness over an extended period. What followed was experimentation with numerous different mixtures of materials over a year long period with the aim of identifying a mixture that would comply with all three requirements mentioned above. These efforts produced a standardized combustion chamber that fulfilled the requirements as much as it possibly could, but this end product still did not fit the price range that the end-user would be able to afford.

However in March 2014 the standard kitchen performance test was conducted on the stove design that did not include the standardized combustion chamber. The test results showed that this particular design performed adequately, and due to the fact that it requires no construction cost other than the actual installation, we decided to approve it as the final design. The only obstacle still left in our path was to ensure that the inlet and outlet dimensions did not deviate from its original design after a few months use. We have now found a solution to this problem by giving each household two measuring objects that are used to ensure that the dimensions are on standard after applying a fresh layer of clay onto the stove.

In October 2014 a local stakeholder meeting was organized in order to inform the community leaders of the area about our intentions of moving the project to its role-out phase. This role-out phase will entail the dissemination of 5000 stoves within the environmentally challenged context the project is currently being implemented. The long term aim of the ICS project is to be able to provide improved domestic energy solutions that can sustainably be implemented and taken to scale in rural and urban communities in South(ern)-Africa.


We started working on these questions in the second half of 2014.

In October 2014 a local stakeholder meeting was organized in order to inform the community leaders of the area about our intentions of moving the project to its roll-out phase. This roll-out phase will entail the dissemination of 5000 stoves within the environmentally challenged context where the project is currently being implemented. In the year 2015 we have been able to take this project to the first implementation of the roll out phase, thanks to the partnership established with the Energy and Environment Partnership Programme (EEP). This venture was formed with the aim of piloting a delivery model for a voluntary Gold Standard locally build biomass cook stove project. For this new development in the cook stove project a different project area was located to run parallel to the Molati project area. This venture was launched on 1 June 2015 and has the aim of implementing 5000 stoves. By the end of 2015 the team of 32 fieldworkers installed 1500 stoves in the households forming part of the project area of Nwamitwa.

We are very excited about this result, initially; we had many problems with slow installation and with the quality of the stoves that were built. Through trial and error, and working closely with the community, we have been able to overcome these obstacles and we see the possibility of taking the ICS to thousands of households.

One question remains: how are we going to finance this programme? With funding from ICCO, through the Fair Climate Network of Southern Africa, we are developing the procedures to generate Gold Standard carbon credits from our project. We trust that this will provide the funding that is needed.