Methodology

The SEDG GHG Emissions Calculator is a user-friendly tool developed to help SMEs measure their Scope 1 and Scope 2 greenhouse gas emissions. Based on the globally recognised Greenhouse Gas (GHG) Protocol, it enables companies to estimate their emissions using easily accessible operational data. Scope 1 emissions include those from stationary sources like boilers and generators, and mobile sources such as vehicles and forklifts. Scope 2 emissions refer to those generated from the consumption of purchased grid electricity.

How the emissions are calculated

The calculator uses an activity-based approach. This means we ask users to provide direct data such as the amount of fuel used in mobile or stationary combustion sources, the amount of refrigerant topped up during servicing or the amount of electricity consumed. Each activity is then paired with a specific emission factor to calculate the total greenhouse gases (GHGs) produced.

The basic formula used is:
GHG emissions = Activity data × Emission factor

For Scope 1 stationary and mobile combustion sources, each type of fuel theoretically has a specific emission factor for individual greenhouse gases—namely carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). However, these values are typically converted into carbon dioxide equivalent (CO₂e) for standardised reporting. This conversion is based on the Global Warming Potential (GWP) of each gas relative to CO₂. To simplify the process for users, the emission factors incorporated into the calculator are already expressed in CO₂e.

For example:
  • If 1,000 liters of diesel used, we multiply it by theCO₂e/litre emission factor for diesel fuel to get the emissions in tonnes of CO₂e.

Scope 2 emissions from electricity refer to emissions resulting from electricity purchased from the grid. In Malaysia, there are three separate grids, each operated by a different provider: Peninsular Malaysia is served by Tenaga Nasional Berhad (TNB), Sabah by Sabah Electricity Sdn Bhd (SESB), and Sarawak by Sarawak Energy Berhad. Each grid has its own emission factor, as they rely on different fuel sources for electricity generation.

For example:
  • If you input 10,000 kWh of electricity consumed in Peninsula Malaysia, we apply the CO₂e/kWh grid emission factor for Peninsula Malaysia to get the emissions in tonnes of CO₂e.
Emission Factors

For Scope 1 emission factors and GWPs, we use the latest available data from the Intergovernmental Panel on Climate Change (IPCC), which is the leading international source recommended by global GHG accounting standards such as the GHG Protocol. It is also the source used by Malaysia for its national GHG inventory submitted to the United Nations Framework Convention on Climate Change (UNFCCC). In some cases, unit conversions from volume to weight are required, and we refer to reputable sources like the Environmental Protection Agency (EPA) for density values.

For Scope 2 emission factors, we use location-specific data from Malaysia’s three electricity grids, as published by the Suruhanjaya Tenaga (ST). Since emission intensity depends on the fuel mix used to generate electricity, these factors may vary annually. However, the most recent data published by ST is from 2022. In the absence of newer figures, we currently apply the 2022 emission factors to all subsequent years. These will be updated as soon as new data becomes available.