Carbon Calculator
How to Calculate Carbon Footprint?
As the methodology previously states, the first step is performing a carbon audit. This step is about how to measure an organisation’s carbon footprint, which is the quantity of Greenhouse Gas (GHG) emissions that were released due to its activity. Not only demonstrating the carbon impact, but also helping the organisation to identify key areas which need major decarbonising.
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To calculate the carbon footprint of an organisation, data collection is required, although the carbon footprint can be evaluated in any length of period. This is mostly evaluated in terms of an annual footprint that accounts for the impact of all an organisation’s key operations, over the course of a calendar year. Despite this, in some areas, such as supply chain management and manufacturing, they could calculate their carbon footprint in unit of emissions per product. In terms of data collection, the scope of the emissions is defined such that it is relevant to emissions reporting from UK Government GHG Conversion Factors for Company Reporting as follows [1]:
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Scope 1 – Direct Emission
These emissions are from on-site activities that are owned or controlled by the organisation. For example, combustion of primary fuel sources, bioenergy or vehicles owned by the company.
Scope 2 – Indirect Emissions
These emissions are directly from the organisation but not on-site. For example, oversea purchased electricity.
Scope 3 – Others
This entails other activities that release emissions that were not included in the previous two scopes. There range from factors such as waste, water supply & treatment, food and transportation (by non-owned vehicles).
After these scopes are considered, the carbon emissions from each activity can be illustrated using the following equation:
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GHG emissions = activity data x emission conversion factor
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According to the equation, activity data is the record of activity in a fixed unit during the specific period, and the emission factor is represented by the quantity of GHG (carbon dioxide, methane and nitrous oxide) that are released to the atmosphere with an associated activity per unit, sourced from government 2021 GHG conversion factors for Company Reporting. This set of emission conversion factors is updated every 6-months due to new studies, technologies and improved efficiencies.
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Why This Carbon Calculator?
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(Figure.1. Government database)
The figure above presents emission factors of cars in variety of sizes and fuel types such as diesel, petrol, hybrid and more from the GHG conversion factors for Company Reporting. On this site, there are 7,500 emission factors and this can be challenging for users (non-professionals/non-engineers) to navigate and consequently calculate and quantify their carbon footprint from each resource effectively. To approach this problem, the carbon calculator was developed with a user-oriented result.
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The carbon calculator is a tool created using excel, to generate an audit of the current overall carbon emissions of an organisation using government set guidelines and the associated emission factors from the GHG reports. This contains three major scopes: direct emissions, indirect emissions and other emissions, same as in the UK government report. This tool is ideal for small-scale social organisations that have no familiarity with annual carbon auditing. This tool has another feature besides calculating and quantifying the emissions from each activity, but also produces a report which summarises the data through various graphs, allowing the users to visualise and quantify their results clearly and for easy use.
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How to use carbon calculator?
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(Figure.2. Cover page of carbon calculator - Index)
The carbon calculator contains 5 sheets as follows:
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Index
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Scope 1
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Scope 2
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Scope 3
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Report
Yellow coloured tabs require input data while the green one is the automatically generated carbon footprint report. The calculator was developed to be user-friendly based, thus, there are only a few steps to achieve the carbon emissions of an organisation.
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1. Data Collection
Firstly, there is some data required for using this tool; examples as following:
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Purchased electricity and heating in each building (kWh)
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Distance travelled of vehicles (km)
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Number of passengers in different transportation types and their average distances (km)
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Water supply (litres) from billing
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Different types of material usage (ton)
The more detailed data, the more precisely the total carbon emissions will be calculated.
2. Fill in all the necessary collected data into the correct input source and choose the type from the drop-down boxes as required, shown in the three figures below. The emissions from each activity will be calculated after all required input data are completed.
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(Figure.3. Scope 1)
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(Figure.4. Scope 2)
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(Figure.5. Scope 3)
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3. Summarisation of emissions associated with an organisation activity will be generated on the report tabs (shown in the figure below), these include a table of subclassed carbon sources, percentages of them compared to overall carbon emissions, a pie chart of emissions from different sources during the period and bar charts for each scope.
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(Figure.6. Report page)
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Download our tool!
References
[1] Department for Business, Energy & Industrial Strategy (2022). Greenhouse gas reporting: conversion factors 2021. [online] Available at: https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2021.