What is this tool intended for?

The BSF GHG emissions Calculator is specifically Designed to estimate greenhouse gas (GHG) emissions from simplified, small- to medium-scale BSF biowaste conversion operations, and to calculate net emission savings when BSF processing replaces conventional waste disposal (unmanaged landfill or Composting). The tool supports two main use cases: (1) understanding the climate footprint of an existing or planned BSF operation; and (2) estimating the volume of avoided emissions that could be monetized through carbon credits, in support of the 'Waste Management and Carbon Credits' business model for BSF enterprises. The tool explicitly excludes high-end industrial equipment and climate control (HVAC), making it well-suited for the decentralized, labour-based BSF systems common in low- and middle-income countries.

How does this tool work?

The calculator is a macro-enabled Microsoft Excel workbook (.xlsm). Users navigate through a series of input sheets corresponding to different stages of the BSF system, with colour-coded cells indicating where to enter data (orange for required inputs, blue for dropdown selections, and green for optional data). Default values are pre-filled in white cells and are applied automatically when no user data is provided. The sheets cover the following system components:

•        Substrate Preparation Unit: Waste collection transport (vehicle type and distance), substrate size reduction (manual or electric), and substrate mixing (manual or industrial).

•        Reproduction Unit: Feed type (e.g., maize grain, chicken Feed), Feed quantity, transport of Feed, and energy use for ventilation and lighting.

•        Treatment Unit: Biogenic emissions (CH₄ and N₂O) from larval bioconversion, based on substrate type, plus separation equipment.

•        Processing Unit: Larvae sanitizing and drying methods, and frass Composting (biogenic CH₄ and N₂O).

•        Conventional Emissions: Baseline emissions from landfill and Composting disposal of the same waste, used to calculate avoided emissions.

Users first select their country (from a comprehensive list of over 150 countries) and substrate type, and enter their daily waste throughput in tonnes. The tool then applies country-specific Electricity grid emission factors and substrate-specific emission coefficients drawn from peer-reviewed scientific literature and approved GHG methodologies. Results are displayed on two summary sheets showing total BSF facility emissions and net avoided emissions, broken down by system stage and emission type (energy, biogenic, transport, and inputs), expressed both per tonne of waste and per year.

The tool operates using a 'cradle to gate' life cycle Assessment (LCA) boundary and follows approved GHG accounting methodologies. Emissions from Feed and Fertilizer substitution (i.e., avoided emissions from replacing fishmeal or synthetic Fertilizer) are not included in the main calculation, but indicative values are provided for reference.

Who might use this tool and with which types of stakeholders?

The primary users of the BSF GHG Calculator are:

•        BSF operators and entrepreneurs running or planning small- to medium-scale biowaste conversion facilities who want to understand and communicate the GHG impact of their operations.

•        Project developers and investors seeking to assess the carbon credit potential of BSF projects for voluntary carbon markets or national emissions reduction schemes.

•        NGOs, development agencies, and implementing partners supporting BSF value chain development, particularly in African and Asian low- and middle-income country contexts.

•        Researchers and students working on life cycle Assessment, circular economy, or insect-based bioconversion projects.

The tool may also be useful for policymakers and regulators seeking to understand the emission reduction potential of BSF biowaste conversion when compared to conventional waste management.

What stages of a process can this tool support?

The tool primarily supports the planning and operational Assessment stages of a BSF project. It can be used to:

•        Pre-investment planning: Estimate the GHG savings potential of a proposed BSF facility before construction, informing feasibility Assessments and business planning.

•        Pilot monitoring: Compare observed operational parameters against expected GHG emissions and savings during a trial or pilot phase.

•        Carbon credit development: Generate preliminary estimates of net avoided emissions to support the development of carbon credit applications, pending an approved quantification methodology.

•        Reporting and communication: Provide quantitative evidence of climate co-benefits for donor reporting, investor communications, or regulatory submissions.

What skills, capabilities and resources are required to use this tool?

Users need access to a computer with Microsoft Excel (the tool is a macro-enabled .xlsm file and macros must be enabled). Basic familiarity with Excel is sufficient; no programming or advanced modelling skills are required. The colour-coded input system and pre-filled default values make the tool accessible to practitioners without specialist GHG accounting expertise.

Key operational data required as inputs include: the country of operation, substrate type, daily waste throughput (tonnes/day), transport distances and vehicle types, processing equipment types and usage hours, and information on how waste would otherwise be managed (landfill or Composting). Default values based on the SIMBA (Simplified BSF Approach) system are applied where user data is not available. An internet connection is not required to use the tool once it has been downloaded.

Where can this tool be used?

The tool is globally applicable. It includes Electricity emission factors for over 150 countries worldwide, and its substrate emission coefficients and system boundary assumptions are derived from international scientific literature. While the tool's scope and default values are calibrated for simplified, labour-based BSF systems typical of low- and middle-income countries, particularly in sub-Saharan Africa and South/Southeast Asia, it can also be used to assess more mechanized systems in higher-income contexts by adjusting inputs accordingly. The tool does not apply to large-scale industrial BSF operations with automated processing equipment or HVAC climate control, for which more detailed LCA approaches would be appropriate.

Case examples of where this tool has been used

The tool was developed as part of the SWIFT project (Sustainable Waste-based Insect Farming Technologies, funded by SOR4D). Its development and validation drew on operational data from BSF facilities in Uganda, Ethiopia, and Côte d'Ivoire in the BUGS AFRICA project. The tool is referenced in the BUGS Africa Operators Toolkit (CCAC, 2025) as a resource for operators pursuing the 'Waste Management and Carbon Credits' business model, and its default performance parameters are calibrated to SIMBA-scale operations. The underlying GHG methodology was developed by Johanna Brendow as an MSc thesis at EPFL (2025).