In a recent report, The Daily Star presented the success story of several small-scale entrepreneurs producing and marketing improved cook stoves (ICS), commonly known as Bondhu Chula (Friend Stove).

The Bangladesh Council of Scientific and Industrial Research (BCSIR) innovated the environment-friendly Bondhu Chula in the early 1980s, which is designed to let out the smoke produced during cooking through a long pipe in the air outside in such a way that anyone in or outside the kitchen would not be affected by the smoke.

Moreover, no heat would be felt in the kitchen. The stove would also be more fuel-efficient as it would require 50 per cent less firewood and also less cooking time. Besides, since the stove would not cause any smoke inside the kitchen, there would not be any stains from the smoke on the kitchen walls, doors and windows.

To what extent have the expected benefits of Bondhu Chula been actually realised?

To generate empirical evidence on this issue, the Bangladesh Institute of Development Studies (BIDS) carried out field research on the impact of Bondhu Chula. Zabid Iqbal and I jointly conducted the study.

Propensity score matching, a quasi-experiment econometric method, was applied using the 2018 household survey data of the BIDS that collected information from 600 users of Bondhu Chula and 396 users of traditional cook stoves.

It was found that about 90 per cent of the study households depend on fuelwood for their energy need for cooking, whether they use Bondhu Chula or not. Other fuels used by both groups of households included tree leaves, hay or jute cake, dung and wooden powder.

Except for cow dung, the energy consumption was much less among households using Bondhu Chula compared to the households using traditional cook stoves. This indicates the efficiency of Bondhu Chula in terms of fuel need. The efficiency of Bondhu Chula in fuel use was also observed by comparing the energy use of households before and after the installation of Bondhu Chula.

The pertinent statistics showed that energy use significantly dropped after the installation of Bondhu Chula. This was observed for all types of fuel used by Bondhu Chula users.

From these results, one can conclude that the use of Bondhu Chula significantly lowers biomass energy consumption. One can also infer that this reduction of energy use significantly reduces air pollution and deforestation because 91 per cent of the sampled households used fuelwood for the purpose of cooking and the sources of fuelwood were mainly trees.

The results of the econometric exercise show that the impact of Bondhu Chula use on household biomass energy is significant. It was found that the use of Bondhu Chula reduces the per capita biomass fuel consumption on average, with a range of 9.75 kg to 12.25 kg per month. In terms of percentage reduction, this is about 30-37 per cent compared to the amount of biomass fuel used by traditional cook stoves.

The laboratory test, as conducted in Bangladesh by the BCSIR, claims that Bondhu Chula saves 50 per cent fuel compared to traditional cook stoves. The difference between claimed fuel reduction and empirically obtained reduction is perhaps due to varying cooking habits practised by the surveyed households.

Based on the above findings, we can take the average level of savings in biomass fuel consumption due to the use of Bondhu Chula to be about 11 kg per household member per month, which is about 600 kg per household per year.

With more than 29 million households, Bangladesh has a great market potential for Bondhu Chula. With 67 per cent of households using more than one stove, this could increase the total number of stoves to more than 50 million. Taking this potential market into account, we calculate that potential fuelwood consumption saving is about 30 million tonnes per year, which is about 51 per cent of the country's total fuelwood consumption.

When converting this biomass fuel-saving into the potential reduction of carbon dioxide emission, we obtain that the use of Bondhu Chula would potentially reduce 50.49 million tonnes of carbon dioxide emission per year nationally.

The next issue examined was the impact of Bondhu Chula on health outcomes.

It is very common that women in Bangladesh are responsible for cooking and thus they are mostly affected by indoor air pollution, which is likely to affect the health outcomes related to indoor air pollution. Household air pollution caused by cooking with biomass fuel has negative impacts on health.

Several studies showed the association between exposure to particles (caused by burning fuelwood) and respiratory diseases such as pneumonia or asthma. In this respect, the Bondhu Chula users were asked whether the use of the stove reduced indoor air pollution.

About 99 per cent of households reported that the use of Bondhu Chula reduced indoor air pollution. Thus, it is likely that the frequency of health problems associated with air pollution will reduce in the households with Bondhu Chula.

The estimated results also show that the use of Bondhu Chula significantly reduces the air pollution-related health problems of women. The health outcomes in this study are self-reported and measured in terms of the number of eye irritation and the number of respiratory problems a woman suffers per month.  For both eye-related and respiratory problems, study results show significant negative effects (i.e., health-improving effects). 

The results show that women with Bondhu Chula have on average 5.55-6.66 times lower eye irritation compared to the women who use traditional stoves and the same women have on average 0.90-1.28 times lower respiratory problems relative to women who cook using traditional stoves. Overall, our findings suggest that positive and significant health-improving outcomes are associated with the use of Bondhu Chula.

The use of Bondhu Chula is likely to affect through two channels the time allocations of women who are involved in cooking: first, Bondhu Chula may have an effect on the cooking duration by speeding up the cooking process and second, a reduction of fuel consumption may imply time savings in obtaining the fuel, be it in terms of collecting or buying it. In case Bondhu Chula has triggered time savings, households may then reallocate the freed-up time to other activities in a second-round effect.

The results of the study show that the use of Bondhu Chula does reduce the household cooking time. This means Bondhu Chula affects the time savings of women through the first channel, i.e., speeds up the cooking process by efficiently using the fuel and therefore cooking time reduces.

Our results also show the effect of the second channel on time savings. The results show that the use of Bondhu Chula reduces the biomass fuel consumption and, therefore, the fuel collection times reduces.

From the survey data, we found that households with Bondhu Chula spend about 200 minutes lower time in collecting fuelwood compared to households with traditional cook stoves, mainly due to the reduction of biomass energy caused by Bondhu Chula use. Thus, women have more leisure time or allocate their time to some other productive activities.

The story of Samiul Islam of Lalmonirhat and Shahedul Islam of Kurigram narrated in The Daily Star story indicates that institutional efforts aimed at popularising Bondhu Chula are bearing fruit. But there is still a long way to go.

The report mentioned that only about 4.5 million out of a potential of 50 million Bondhu Chula have so far been installed. This means that the drive to raise awareness about the benefits of Bondhu Chula needs to be intensified.

The authors are economists.