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Cookstoves in the VCM

  • Matt Lavelle
    Senior Carbon Ratings Scientist
  • Annie White
    Ratings Editor
Improved cookstove projects account for nearly 1 in 7 projects in the Voluntary Carbon Market (VCM) and, when successful, can provide carbon benefits through emission reductions. Due to variations in the standards required by project accreditors, the carbon efficacy of these projects can vary.

Read our introduction to cookstove projects in the VCM, and the key risks and uncertainties to consider when assessing their carbon efficacy.

Here are some key takeaways

  • Improved cookstove projects account for 14 percent of projects on the VCM, but the quality and efficacy of the carbon credits assigned a BeZero Carbon Rating varies.

  • The variation in the quality of the credits reflects the multiple approaches used by projects for baseline-setting tools and survey techniques.

  • BeZero has identified several practices, including using field-based rather than lab-based tests to set emissions baselines, applying conservative assumptions about baseline fuels, and conducting in-person follow-up surveys, which can mitigate risks to the project’s carbon efficacy.


Please note that the content of this insight may contain references to our previous rating scale and associated rating definitions. You can find details of our updated rating scale, effective since March 13th 2023, here.

Cookstove projects account for 14 percent of projects on the VCM. These projects aim to address the emissions produced by the 30 percent of the world’s population that use polluting fuels for household heat and cooking (Chart 1).

Chart 1. Cookstove projects by country

Cookstove projects are divided into two categories: improved efficiency projects and fuel-switch projects. Improved efficiency stoves are more common. They replace traditional cooking equipment, which typically consist of an open or partially-covered flame fed by biomass in the form of wood or dung cakes, with technology that is more efficient but still relies on traditional fuels. Fuel-switch projects replace traditional equipment with stoves that burn cleaner liquid fuel, such as liquified petroleum gas (LPG).

When effective, cookstove projects can reduce emissions compared to traditional stoves, which emit CO₂, CH₄, and N₂O.  The use of improved cookstoves is also associated with potential health benefits from lowered exposure to soot and smoke and improved indoor air quality. But the carbon efficacy of cookstove credits depends heavily on the project’s design, while the accuracy of credit accounting relies on the strength of the project’s methodology and its application.

Cookstoves in the BeZero Carbon Rating

BeZero analyses each project it rates based on six carbon risk factors. Additionality and over-crediting tend to be the most important drivers of a project’s overall BeZero Carbon Rating (BCR). At the time of writing, the rating of credits from cookstove projects is skewed to a AA or AA- BeZero Carbon Rating. This represents a moderate likelihood of achieving 1 tonne of CO2e avoidance or removal. Our analysis of a variety of cookstove projects across three accrediting bodies identified several practices that can reduce the uncertainty inherent in carbon crediting and correspond to higher carbon efficacy.

Types of Projects and Barriers to Adoption

Most cookstove projects seek to improve the efficiency of traditional cookstoves so that less fuel is used in cooking, but some projects use cookstoves powered by alternative fuels, such as liquid gas. Fuel switch projects are comparatively rare: they make up 11 percent of the cookstove projects rated by BeZero, a percentage that is broadly representative of the market as a whole.

Fuel-switch projects are typically more impactful from an emissions standpoint than improved efficiency projects. This is because they produce far less particulate matter and carbon monoxide emissions than traditional stoves, as well as up to six times less CO₂ emissions than a stove burning biomass fuel. Fuel-switch projects also provide greater additionality compared to improved efficiency stoves, due to the higher financial barriers to households adopting the technology without outside support.

In general, BeZero finds that projects that use their funding to provide outreach, education, and long-term support to households involved in the project may have greater and more sustained adoption than projects which simply provide households with free or subsidised new stoves. Lack of education about the indoor air-quality benefits of improved cookstoves and resistance towards adopting a new cooking technology are important barriers to cookstove adoption that could be mitigated via outreach.

Limited access to alternatives to biomass fuel is another systemic barrier to the adoption of improved cookstoves. Globally, 85 percent of households have access to clean cooking fuels, while only 42 percent of the world’s rural population has the same access. Many rural areas lack robust infrastructure and dependable supply chains. Those issues may be more important to long-term adoption rates than the cost of fuel. In two examples that illustrate global constraints, policy efforts in Senegal and India have shown that subsidising LPG costs alone is not enough to drive adoption in rural areas. This suggests that cookstove projects that work to expand the infrastructure that would allow consistent access to clean fuels may be more effective than those that simply subsidise the cost of stoves or fuel.

This does not mean that the cost (or perceived cost) of the stoves is never a barrier to cookstove adoption. However, those reservations do not always reflect the actual cost of the new stoves. The low-end cost of improved efficiency stoves aligns closely with those of traditional stoves, suggesting economic concerns are not always the main barrier to adoption. The high rate of adoption of mobile phone technology, for instance, further suggests that many households can manage the costs of new technology. These variables need to be taken into account when considering a project’s additionality.

Cookstove Project Methodologies

Methodology choices also contribute to uncertainty around a credit’s carbon efficacy and the accuracy of the project’s issuances (or risk of over-crediting). Because long-term use is so important to the emissions reductions realised by cookstove projects, project proponents are required to evaluate the proportion of households that permanently adopt the new stoves. Accreditors even allow for these surveys to be conducted over the phone, and the surveys sometimes consist of a small, non-representative sample of households involved in the project.

BeZero finds that more frequent, in-person monitoring provides a better assessment of the adoption rate of improved cookstoves. This monitoring technique is more labour-intensive, but would help to determine whether factors other than lack of adoption are reducing the project's carbon efficacy. For instance, follow-up studies show that many or even most households continue to use old stoves alongside new ones in a practice referred to as stove-stacking. Households may use stove-stacking to provide indoor heat and light, repel mosquitos, or because the traditional stoves serve a socio-cultural purpose.

The calculations used to set baseline assumptions for fuel use are, in some cases, based on inaccurate assumptions about fuel use and deforestation in the project region, and therefore contribute to uncertainty around over-crediting. One measure, fraction of non-renewable biomass (fNRB), estimates the percent of biomass that, due to a project’s activities, is not burned as fuel, and that would likely have come from non-renewable sources, therefore contributing to deforestation. Recent research shows that the default fNRB values used for some countries are artificially high (some as high as 99 percent), and reflect neither diverse sources of fuel nor varied causes of deforestation. The use of more conservative assumptions would likely reduce the risk of over-crediting.

There are three tests of fuel consumption currently in use by the various accreditors to set baseline assumptions for the amount of fuel saved by improved cookstoves compared to traditional stoves. Two lab-based tests, the Water Boiling Test and Controlled Cooking Test, measure the amount of a standard fuel required to cook a standard meal or boil 5 litres of water using a given stove. The Kitchen Performance Test (KPT), mandated for projects on the Gold Standard registry and available to projects on the ACR, CDM, and VCS registries, is conducted in the field instead, so is more likely to reflect the performance of the fuels used in the project area under common local cooking practices. Because it is conducted in a real-world setting, the KPT is best-practice, and projects that use the other two tests introduce more uncertainty into their baseline calculations.

Best Practices

Given the large number of cookstove projects on the VCM—BeZero data analysis shows that as well as accounting for 14 percent of projects, improved cookstoves also represent 3 percent of outstanding credits —the uncertainties and variations in baseline-setting and monitoring techniques used among the many projects are meaningful to the market as a whole.

BeZero’s analysis finds appreciable differences among the various methodologies used to measure the efficacy of cookstove projects, but also provides insight into practices that can reduce uncertainty and improve the carbon efficacy of cookstove projects.

Cookstove projects that use the KPT to set emissions baselines, use conservative assumptions to calculate fNRB, and conduct thorough, regular monitoring studies are more likely to mitigate efficacy risks present in this sub-sector.

To learn more about cookstoves in the VCM, see Carbon Ratings Analyst Matthew Lavelle talk through them here.