How Are Emission Reductions Calculated in Cookstove Projects?

hummingbirds, has a strong focus on Nature-based Solutions (NbS), but we also work on Efficient Cooking Solution projects, also known as Improved Cookstove (ICS) projects.

These projects are designed to reduce carbon emissions by increasing the cooking efficiency, consequently decreasing the quantity of fuel needed, in particular woody biomass.

Traditional cooking methods, notably three-stone fire, release a large quantity of toxic pollutants that pose serious health risks, especially to women. They also consume a lot of fuelwoods, which results in forest degradation and deforestation.

By replacing these traditional methods with more efficient cookstoves, we can significantly reduce emissions, improve air quality and reduce respiratory diseases, save time for women and children, and allow them to pursue education and economic activities.

Types of Cookstove Projects

There are two main types of cookstove projects in the Voluntary Carbon Market (VCM):

1. Improved Efficiency Cookstoves – These stoves enhance efficiency while continuing to use the same traditional biomass (wood or charcoal). They require less fuel to cook the same amount of food, thereby reducing deforestation and carbon emissions.
2. Fuel-Switching Cookstoves – These stoves replace traditional biomass with cleaner fuels like LPG, ethanol, or biogas, which produce fewer emissions.

Among these, Improved Efficiency Cookstoves are the most common in the VCM. Currently, there are more than 1,800 registered projects across different standards, with over 113 million carbon credits issued.

How Are Emission Reductions Calculated?

Simply put, the emission reductions in cookstove projects are determined by comparing the amount of fuel used before and after the introduction of improved cookstoves. This calculation follows a methodology that ensures accuracy and transparency in measuring carbon savings. Some of the methodologies currently available are the Reduced emissions from cooking and heating – Technologies and Practices to displace Decentralised Thermal Energy Consumption (TPDDTEC) from Gold Standard and VM0050 Energy Efficiency and Fuel-Switch Measures in Cookstoves, v1.0 from the VCS standard.

Key Parameters in Emission Reduction Calculation

If we see the equation used to calculate the total emission reductions for a cookstove project, it might look quite complex:

Source: Gold Standard TPDDTEC methodology

Therefore, understanding the parameters that estimate the total GHG emissions avoided is very important. Overall, the following factors are considered:

1. Fuel Savings (SFS)

The key goal of ICS projects is to reduce the amount of biomass required for cooking. Fuel savings can be measured in two ways:

• Kitchen Performance Tests (KPTs): A direct measurement of fuel consumption in real households before and after switching to improved cookstoves.
• Controlled Cooking Tests (CCTs): A field test that measures how much fuel a traditional stove and an improved stove use to cook a specific meal, under controlled conditions. For that, a trained person cooks the same meal on both stoves using a standard method and recipe.
• Number of Cookstoves Distributed (N)

The total number of cookstoves distributed and the date when each cookstove starts to be operational are very important factors, as they will multiply the total amount of wood savings daily.

• Usage Rate (U)

The total usage rate is the percentage of households actively using the improved cookstove. There are two main methods to estimate this number:

• Yearly usage surveys conducted to track stove adoption, and/or
• Stove utilization monitors (SUMs) put in place to measure direct indicators such as temperature, heat flow, or light intensity, which serve as a proxy for cooking events and consequently cookstove usage.

• Fraction of Non-Renewable Biomass (fNRB)

Not all biomass is renewable. The fNRB parameter estimates the percentage of harvested wood that exceeds natural regeneration rates, meaning it contributes to deforestation/forest degradation.

This parameter can be estimated either using models such as MOFUSS or using the default value of 0.3 (30%) provided by the Clean Development Mechanism (CDM).

At hummingbirds, we use the most up-to-date values from MOFUSS, a GIS-based dynamic model that simulates fuelwood harvesting impacts across landscapes. This ensures a more precise and conservative calculation of non-renewable biomass usage.

•  Emission Factors (EF)

Each type of fuel has a specific emission factor—a default value representing the amount of GHG released per unit of energy. The emission factors are provided by carbon methodologies, ensuring consistency across projects.

• Net Calorific Values (NCV)

NCV represents the energy content per unit of fuel. Each type of biomass has a specific NCV, which influences the amount of fuel required for cooking. This parameter is also a default value provided by methodologies.

• Leakage

Leakage is calculated by assessing whether the reduced fuel consumption in project households leads to increased fuel use elsewhere.

• This includes activity shifting leakage (e.g., displaced stoves being used by others) and market leakage (e.g., changes in fuel demand affecting supply chains).
• Leakage is typically quantified as a percentage of total emission reductions and deducted from the final carbon credit calculation to ensure conservative estimates.

Why Do These Calculations Matter?

Accurate carbon calculations ensure that cookstove projects:

• Generate high-quality and credible carbon credits in the voluntary market.
• Provide measurable climate impacts.
• Demonstrate real-world benefits for local communities.
• Ensure compliance with international carbon standards.

Final Thoughts

Cookstove projects are a powerful tool in the fight against climate change, forest degradation and air pollution. By improving fuel efficiency and reducing emissions, they protect both people and the planet.

At hummingbirds, we are committed to ensuring that every carbon credit generated truly reflects a reduction in emissions,. In our improved cookstove projects, we follow the latest Core Carbon Principles guidelines published by the Integrity Council for the Voluntary Carbon Market (ICVCM), including using the fNRB provided by the MOFUSS model, developing appropriate KPT tests, and ensuring good monitoring practices such as the use of SUMs.

An example of this is our Bissap project, which aims to deploy 150,000 improved stoves in Benin, positively impacting women’s livelihoods, creating around 40 full-time jobs and reducing indoor pollution.

As we continue to innovate, hummingbirds remains dedicated to delivering real impact—ensuring that carbon savings are measurable, transparent, and scientifically robust.