FAQ

Introduction to Improved Cookstoves

This section explains the problem of traditional biomass cooking, the solutions provided by improved (or “clean”) cooking solutions (ICS), and the choices that The African Stove Company (TASC) makes when it designs and implements projects distributing ICS.

What are the problems with traditional biomass cooking?

Over 1 gigaton of carbon dioxide (CO2) is emitted each year by burning wood fuels for cooking [1]. That figure is approximately 2% of global emissions and comparable to the carbon footprint of the United Kingdom. The carbon footprint of traditional biomass cooking comprises emissions from the woodfuel supply chain, fuel combustion, deforestation, and forest degradation. Wood fuel harvesting and charcoal processing are primary drivers of regional forest degradation across the African continent [2]. Burning wood fuel also creates black carbon (BC) emissions, which are short-lived (8-10 days) but influential for regional precipitation and temperature changes.

Household air pollution (HAP) from cooking causes over 4 million premature deaths each year from conditions including lung cancer, chronic obstructive pulmonary disease, and ischemic heart disease. HAP exposure is responsible for 45% of pneumonia deaths in under-fives and it is leading cause of blindness and low birth weight globally. It is worth noting that there is broad scientific consensus that the breadth of negative health outcomes and the number of ill-health episodes caused by inefficient cooking have likely been underestimated due to insufficient data.

In developing countries, women usually take responsibility for cooking. Their health, and that of their children, is disproportionately impacted by HAP. Inefficient cookstoves require more fuel to be collected and more time in attendance while food is cooked. The aggregate time spent in fuelwood collection and cooking is around 5 hours per day. Injury and violence are commonly overlooked risks of frequently, arduous trips to collect firewood.

Traditional biomass cooking is a problem for public health, gender inequality, our climate, and the local environment. In Sub-Saharan Africa (SSA), where TASC’s work is focussed, the total cost of of traditional open-fire cooking is over $330 billion a year: $186 billion on gender, $96 billion on health, and $47 billion on climate and environment [3]. Replacing traditional biomass cookstoves will improve women’s health, allows them greater economic and social freedoms, and reduce CO2 emissions.

What do you do?

TASC distributes ICS across SSA and monitors reductions in wood fuel use amongst recipient households. We register our projects with reputable international carbon standards to receive verified carbon credits.

Why do you distribute cookstoves?

We distribute ICS to address two acute needs: to reduce the environmental, social and economic impacts of open fire cooking; and, to meet the demand for high-quality carbon credits to meet regulated or voluntary emissions reduction targets.

What is an improved cooking solution? Is it the same as a clean cookstove?

ICS include a range of interventions or appliances designed to improve fuel efficiency and emissions performance in cooking. Most are improved cooking stoves; however, the category also includes products like thermal insulation sleeves.

According to the World Bank Group (WBG) and World Health Organisation (WHO), a clean cooking solution, or clean cookstove, is an advanced ICS that lowers particulate matter emissions to near zero [4]. Clean cookstoves do not burn wood or charcoal but instead use feedstocks like processed briquettes, liquid petroleum gas (LPG), methanol, or even electricity. The name ‘clean cookstove’ is often used to describe all manner of ICS, which can be confusing. TASC doesn’t currently distribute clean cookstoves as per the WHO definition.

Which cookstoves do you distribute?

TASC distributes portable rocket stoves supplied by Burn Manufacturing of Kenya and RocketWorks of South Africa. We purchase different models depending on which country we are operating in and whether the target communities are predominantly wood or charcoal fuel users.

How do portable rocket stoves work?

The central feature of a rocket stove is an ‘L-shaped’ chamber that is designed to moderate airflow into the fire and maximise fuel combustion. Rocket stoves are open where the wood is fed in, allowing lots of oxygen to be drawn into the unit. As the fire starts, rising hot air moves up through the chamber, drawing more air behind it. The insulated combustion chamber only has space for a small amount of fuel to burn at any given time, ensuring almost complete combustion prior to the flames reaching the cooking surface.

Why do you distribute portable rocket stoves?

Improved cookstoves vary widely in terms of the fuel feedstock, construction materials, methods of production, and performance. Some carbon projects distribute ‘basic’ artisan cookstoves or make permanent alterations to ‘legacy’ coal or biomass cookstoves. ‘Basic’ and ‘legacy’ cookstoves achieve minor efficiency gains and negligible reductions in local air pollution. These products are not quality tested, prone to malfunction or degradation, and relatively expensive considering their overall impact.

We distribute portable rocket stoves because they:

    • achieve the highest fuel efficiencies for biomass stoves (over 50% improvement on traditional stoves)
    • achieve, on average, 60 percent HAP reduction [4], which is the highest combustion efficiency for biomass stoves
    • are manufactured in special purpose factories to maximise durability and consistency
    • are reported to last up to 10 years
    • are financially viable for use in carbon credit projects; and,
    • allow people to cook traditional meals using fuel that is readily available in their community
Why don’t you distribute LPG or electric stoves?

LPG and electric stoves are difficult to distribute for two reasons:

    • There isn’t suitable fuel supply in remote rural communities, and;
    • The products are too expensive to distribute under a carbon credit model

LPG and electric stoves can take us from 60% HAP reductions to over 90%. In the future, we hope the price of carbon credits can support the dissemination of LPG and electric stoves.

What are the traditional cooking solutions that you are replacing?

Most families use ‘3-stone’ fires, where pots are balanced on rocks, or ‘Os’, which are a circular metal pot stand. 3-stones are most common amongst rural, wood fuel users. In peri-urban and urban areas we find basic charcoal stoves called ‘Mbalula’, which resemble an old washing machine drum, or a metal bin with holes drilled through the sides.

Where do you work?

We are currently active in South Africa, Zambia and Zimbabwe.

What is the level of need in these countries?

In Sub-Saharan Africa (SSA), approximately 729 million people, or 73% of the regional population, have no access to any ICS [1, 3].

    • 88% of rural Zambian households have no access to electricity and just 2% have an electric cooker. In total, over 83% of households cook with biomass; 46% burn wood on 3-stone fires, and over 36% use Mbalula, mainly with charcoal [5].
    • 95% of rural Zimbabwean households rely on firewood or charcoal for daily cooking. 66% of urban households are connected to the grid but unreliable supply forces many to employ charcoal stoves as the primary mode of cooking [6, 7]. ICS are beyond the reach of most household budgets, due to the upfront cost.
    • South Africa has high rates of electrification and most of the population does not rely on biomass fuel. Nevertheless, disparate rural communities live a world apart from the urban centres and receive little to no social support from the national government. Thus, we have identified communities where SA citizens and economic migrants face the same issues as in Zambia and Zimbabwe.

All the areas in which we operate suffer from high annual increases in deforestation, combined with high proportions of woodfuel use. The link between woodfuel consumption and deforestation is highly localised and, charcoal supply in particularly, is considered a primary cause of deforestation [8].

How do you distribute the cookstoves?

Distribution starts with sensitization, which is the dissemination of information about the proposed project to local communities. The objectives of sensitization are to maximize the adoption of the new stove and eliminate the use of traditional stoves. Sensitization meetings are arranged through local tribal authorities, which helps ensure the project is promoted in a culturally appropriate fashion. Attendees receive a presentation on the benefits of the efficient stove, how to cook with it, and how to obtain one. Afterward, the names and addresses of those who would like a stove are collected. Only one cookstove is allowed per household.

Several days later, our team will return to each village to distribute the stoves. They use a mobile application to collect data on the recipients, including full name, social security number, proof of identity, address, family size, GPS location etc. The recipients also sign an End User Agreement. The agreement confirms that they understand that TASC retains the rights to monitor the stove usage and the ownership of any carbon credits that may be obtained by doing so.

Why do you give the cookstoves away for free?

We give stoves away in exchange for the exclusive right to monitor them and sell carbon credits associated with their performance. We find this is the most efficient method of distribution. Demanding any cash payment – upfront, financed, or concessionary –dramatically reduces uptake because our target beneficiaries cannot afford it. Contrary to popular belief, we do not find beneficiaries to be less willing to look after stoves that they didn’t pay for. Our experience is supported by academic research [9].

How do you measure the performance of the cookstoves?

The primary measurement of cookstoves’ performance is reduction in fuel use and, consequently, the reduction in carbon dioxide equivalent (CO2e) emissions. This is how the issuance of carbon credits is determined. CO2e savings are calculated by following methodologies by the Gold Standard or the Verified Carbon Standard. The Gold Standard provides guidance on how other project impacts – health and gender – can be extrapolated from the data on stove usage.

Each year, the project scenario is compared with the baseline scenario to calculate the average fuel savings per unit (stove/household). Both scenarios are determined by a conducting a habit survey and a kitchen performance test (KPT) to understand how households cook before and after the introduction of new stove, and to calculate fuel usage.

The habit survey is used in both baseline and project scenario to determine household cooking habits, stove usage, and household demographics. The KPT is used to directly measure fuel consumption over a 24-hour period. The KPT is performed over 4 consecutive weekdays. Project field officers randomly select households from the database and visit them every 24 hours to weigh a stockpile of fuel and measure the change from day to day. The field officers instruct the participant households to consume fuel using all cooking technologies that they would normally use. Participants cook typical daily meals but avoid large social occasions. If secondary stoves are used, their emissions are included in the results.

All field testing and surveys measure real cooking habits and fuel use in a statistical sample of participant households, chosen using a randomised selection technique. The habit survey sample size is determined by using the “Sampling and surveys for CDM project activities and programmes of activities” document. Projects over 1000 devices are required to have a minimum sample size of 100 surveys but we oversample to 120 to account for possible anomalies and/or survey errors. For KPTs, the following guidelines apply. A statistically valid sample can be used to determine parameter values, as per the relevant requirements for sampling in the latest version of the CDM Standard for sampling and surveys for CDM project activities and programme of activities. 90% confidence interval and a 10% margin of error requirement shall be achieved for the sampled parameters unless mentioned otherwise in the methodology. In any case, for proportion parameter values, a minimum sample size of 30, or the whole group size if this is lower than 30, must always be applied.

As we are following the 90/10 approach with a covariance of 0.4, we are required to do a minimum of 45 samples. However, it is suggested to oversample to at least 60 tests to provide the ability to remove outliers and exclude any tests where experimental errors have occurred.

After sampling, fuel savings per device are calculated by comparing the project scenario against the baseline scenario. Fuel savings are multiplied by CO2 and non-CO2 emission factors and divided by 365 to calculate the total tonnes of CO2e reduced per device per day. This value is multiplied by the total number of technology days – the sum of days all devices have been active in the monitoring period – resulting in the gross emission reductions (in tCO2e) for the monitoring period.

TASC takes several steps to ensure project success, including:

    • our own proprietary cloud-hosted database for collecting records of stove distribution, including contact information, GPS locations, archived stove purchase agreements, financial accounts and distribution records, all of which is used for spot checking and cross referencing by a third-party auditor.
    • In-house monitoring (beyond verification or compliance monitoring) and community engagement is conducted throughout the project lifespan to identify where and when stoves may be underused and inform where additional training is required to maintain a high usage of stoves.
What is thermal efficiency? Why is it different to fuel reduction?

Thermal efficiency (TE) describes the fraction of heat energy that is put to work. In this case, it is the fraction of heat transferred to the cooking pot. The TE of our ICS is approximately 40%, while TE of an open fire is approximately 10%. That means 90% of the heat energy is lost. We can calculate overall fuel savings by calculating the percentage difference between the old and new TE, as follows:                                               

(1-(TEold/TEnew))*100                                   

(1-(10/40))*100 = 75%                                        

The higher TE of the ICS means that ~75% less fuel is needed than cooking the same meal on an open fire.

References

[1] Bailis et al. 2015. The carbon footprint of traditional woodfuels. Nature Clim Change 5, 266–272 (2015). https://doi.org/10.1038/nclimate2491

[2] Hosonuma et al. 2012. An assessment of deforestation and forest degradation drivers in developing countries. Environ. Res. Lett. 7 044009. Available online: https://iopscience.iop.org/article/10.1088/1748-9326/7/4/044009

[3] Energy Sector Management Assistance Program (ESMAP). 2020. The State of Access to Modern Energy Cooking Services. Washington, DC: World Bank. License: Creative Commons Attribution CC BY 3.0 IGO. Available online: http://documents1.worldbank.org/curated/en/937141600195758792/pdf/The-State-of-Access-to-Modern-Energy-Cooking-Services.pdf

[4] Energy Sector Management Assistance Program (ESMAP). 2015. The State of The Global Clean and Improved Cooking Sector. Washington, DC: World Bank. License: Creative Commons Attribution CC BY 3.0 IGO. Available online: https://openknowledge.worldbank.org/bitstream/handle/10986/21878/96499.pdf?sequence=1

[5] Luzi et al. 2019. Zambia – Beyond Connections: Energy Access Diagnostic Report Based on the Multi-Tier Framework (English). Energy Sector Management Assistance Program (ESMAP) Washington, D.C. World Bank Group. Available online: http://documents.worldbank.org/curated/en/477041572269756712/Zambia-Beyond-Connections-Energy-Access-Diagnostic-Report-Based-on-the-Multi-Tier-Framework

[6] Johnstone, Kevin. 2020. Stoking Finance for Affordable Cookstoves: Experience from Malawi and Zimbabwe. International Institute for Environment and Development. Available online: https://pubs.iied.org/sites/default/files/pdfs/migrate/G04472.pdf

[7] Zimbabwe National Statistics Agency. 2017. Inter-censal demographic survey. Available online: http://www.zimstat.co.zw/wp-content/uploads/publications/Population/population/ICDS_2017.pdf

[8] van Dijk et al. 2019. Assessing the land-energy nexus in Southern Africa: An integrated assessment and scenario approach. In: EGU General Assembly 2019, 7-9 April 2019, Vienna, Austria. Available online: http://pure.iiasa.ac.at/id/eprint/16860/1/20190409.PalazzoVanDijkEGU.pdf

[9] Bensch, Gunther; Peters, Jörg (2012) : A Recipe for Success? Randomized Free Distribution of Improved Cooking Stoves in Senegal, Ruhr Economic Papers, No. 325, ISBN 978-3-86788-374-0, Rheinisch-Westfälisches Institut für Wirtschaftsforschung (RWI), Essen,

http://dx.doi.org/10.4419/86788374

Introduction to Ceramic Water Filters

This section will outline the problems faced by those without access to clean water, the solution provided by the distribution of purifying filters, and the choices that The African Stove Company (TASC) makes when it designs and implements projects distributing these filters.

What risks are associated with unsafe water supply?

Contaminated water and poor sanitation are linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid and polio. Absent, inadequate, or inappropriately managed water and sanitation services expose individuals to preventable health risks. Inadequate management of urban, industrial and agricultural wastewater means the drinking-water of hundreds of millions of people is dangerously contaminated or chemically polluted. Natural presence of chemicals, particularly in groundwater, can also be of health significance, including arsenic and fluoride, while other chemicals, such as lead, may be elevated in drinking-water because of leaching from water supply components in contact with drinking-water.

Some 829 000 people are estimated to die each year from diarrhoea because of unsafe drinking-water, sanitation and hand hygiene. Yet diarrhoea is largely preventable, and the deaths of 297 000 children aged under 5 years could be avoided each year if these risk factors were addressed. Where water is not readily available, people may decide handwashing is not a priority, thereby adding to the likelihood of diarrhoea and other diseases.

Diarrhoea is the most widely known disease linked to contaminated food and water but there are other hazards. In 2017, over 220 million people required preventative treatment for schistosomiasis – an acute and chronic disease caused by parasitic worms contracted through exposure to infested water.

In many parts of the world, insects that live or breed in water carry and transmit diseases such as dengue fever. Some of these insects, known as vectors, breed in clean, rather than dirty water, and household drinking water containers can serve as breeding grounds. Simple interventions such as covering water storage containers or daily filtration can reduce vector breeding and may also reduce faecal contamination of water at the household level.

What do you do?

TASC currently distributes ceramic water filters in Western Uganda and monitors water use and reductions in wood fuel use that would have been required to purify household water. We register our projects with reputable international carbon standards to receive verified carbon credits.

Why do you distribute ceramic water filters?

We distribute ceramic water filters to address two acute needs: to reduce the combat and reduce the risks associated with unsafe water use; and, to meet the demand for high-quality carbon credits to meet regulated or voluntary emissions reduction targets.

Which water filters do you distribute? How do these filters work?

The Purifaaya ceramic water filter will be distributed by TASC in Uganda. These filters are produced by SPOUTS of Water Ltd in Uganda. SPOUTS have been manufacturing and distributing water filters, in Africa, since 2012. The ceramic water filter sits in a 20 litre plastic container which is perfect for households of up to 8 people. It provides up to 5 years of safe drinking water with replacement filters available.  The two diagrams below explain their process and function.

Technology of Ceramic Filter
How are these filters certified as fit for purpose?

Purifaaya water filters have been used in 5 registered Gold Standard VPAs (Verified Project Activity) for clean water dating back to 2017. In addition, SPOUTS has a 1-star rating water filter rating from the World Health Organisation (which is the level given to filters that filter Bacterial water borne diseases), SPOUTS has certification from the relevant water authorities in Rwanda, Tanzania and Uganda. They are also currently undergoing the necessary tests to get certification in Nigeria and South Africa. Furthermore, the Purifaaya filters have undergone and passed testing in Uganda for bottled water grade water purity.

How long do these filters last?

These filters are replaced after a 5-year period. The easy-to-use filter system requires cleaning once every 2-3 weeks and basic care instructions are provided. 

Where will these filters be distributed?

TASC currently distributes ceramic water filters in the Western region of Uganda in the Toro Kingdom, specifically in the Kamwenge and Kyenjojo districts. TASC aims to distribute these filters throughout Sub-Saharan Africa.

How do you distribute the ceramic water filters?

Distribution starts with sensitization, which is the dissemination of information about the proposed project to local communities. The objectives of sensitization are to maximize the adoption of the new ceramic filters. Sensitization meetings are arranged through local tribal authorities, which helps ensure the project is promoted in a culturally appropriate fashion. Attendees receive a presentation on the risks of unsafe drinking water, the benefits of sing ceramic filters, how to effectively use and clean the filters. At this point, the names and addresses of those who would like a filter are collected.

After the presentation and training, the filters will be distributed. They use a mobile application to collect data on the recipients, including full name, social security number, proof of identity, address, family size, GPS location etc. The recipients also sign an Filter receipt Agreement. The agreement confirms that they understand that TASC retains the rights to monitor the filter usage and the ownership of any carbon credits that may be obtained by doing so.

What is the level of need in these countries?

According to the United Nations and World Health Organisation’s Joint Monitoring Programme, 19 percent of the Ugandan population relies on unimproved or surface water for their daily household needs. In a population of 45 million this means that 8 million people are drinking from streams, ponds, unprotected hand dug wells and other unsafe water sources. In addition, a further 32 percent has limited access where the water source is likely to be safe but it takes the average person 30 minutes or more to retrieve it because of travelling distance, queueing or both. 

This means that over 21 million people in Uganda are living without basic access to clean drinking water. The vast majority of people rely on water boiling to purify their water and prevent water borne diseases like diarrhoea, typhoid and cholera. 

According to UNICEF, Eastern and Southern Africa (ESA) ranks lowest in access to at least basic drinking water services. Over 226 million people in ESA (47 per cent) have no access to at least basic drinking water services. The highest burden is in countries like Ethiopia (61 million), Uganda (27 million) and Tanzania (24 million). Water supply in institutions (schools and heath care facilities) is not any better. In schools, for example, over 78 million (42 per cent) school-age children have no access to drinking water services in schools.

Why are these filters given away for free?

The ceramic filters are given away for free in exchange for the exclusive right to monitor them and sell carbon credits associated with their performance. We find this is the most efficient method of distribution. Demanding any cash payment – upfront, financed, or concessionary –dramatically reduces uptake because our target beneficiaries cannot afford it. As these filters directly reduces their risk of illness, we do not find beneficiaries to be less willing to look after filters that they didn’t pay for.

How are emission reductions calculated from the use of water filters?

According to restrictions outlined in the Gold Standard methodology used for this project, a household is limited to a total daily water use of 5 litres per person. This figure is used in conjunction with data on water energy requirement for boiling, thermal efficiency of traditional fires, and net calorific values of wood fuel in order to estimate the daily wood use per household. This conservative daily wood use estimation, and its associated emissions from combustion are set as the baseline scenario before the distribution and use of ceramic water filters. As a result of the use of these filters, emission reductions can be calculated from the prevention of the use of wood fuel for boiling and purifying household water.

How do you ensure your measurements are accurate?

The first step to successful monitoring, reporting and verifying (MRV) project CO2e emissions reductions is a complete record of filter sales/distribution. TASC must make all its records accessible for spot checking and cross referencing by a third-party auditor. Contact information or GPS locations must allow a project auditor to easily contact and visit end users. An auditor must also be able to cross reference pertinent project documentation, including archived filter purchase agreements, financial accounts and distribution records. TASC uses a custom-built, cloud-hosted database for all data collection and monitoring.

The second step is analysis of usage after distribution of the new ceramic filters, and confirmation that wood fuel is not being used for purifying water through boiling. The project scenario relies upon monitoring and usage surveys. The former investigates changes in how much filters are used, how much water they are used for, and seasonal variations in either. The results of a monitoring survey can lead to increases or decreases in the volume of carbon credits that can be issued for each project filter.

Monitoring visits to households with happen at least once a year, with calls being made twice a year to confirm usage and maintenance over the project lifetime.

References

WHO fact sheet – Drinking Water. March 2022. https://www.who.int/news-room/fact-sheets/detail/drinking-water

UNICEF -Water and Environment. https://www.unicef.org/esa/water-and-environment