Playbook for CO2 emission calculation

Description of how the Proxio platform is constructed to calculate accurate emissions for various use cases.

Written By Mattias Hägerstrand

Last updated 1 day ago

Introduction

This white paper describes the methodology used to calculate freight emissions in the application Proxio Emissions.

Our mission is to speed up the transition to sustainable transport by making the emissions and freight pricing visible and transparent.

By using our software:

Methodology partners

Proxio bases it´s methodology on current science by cooperating with independent parties who´s expertise is to evaluate and compile data and science.

Smart Freight Center

Smart Freight Centre (SFC) is an international non-profit organization focused on reducing the emission impacts of global freight transportation.
https://www.smartfreightcentre.org

The Network for Transport Measures

The Network for Transport Measures (NTM) is a non-profit organization that works independently of partial interests to establish methods and data which enable credible calculations of transport environmental, climate and energy performance.
https://www.transportmeasures.org

Compliance

GHG, Greenhouse Gas Protocol is a global standardized frameworks to measure and manage greenhouse gas (GHG) emissions from private and public sector operations, value chains and mitigation actions.

GLEC, Global Logistics Emissions Council has developed the GLEC framework to make it possible to compare emission between different modalities. Designed to inform business decisions and steer efforts to reduce emissions.

EN 16258:2012, Methodology for calculation and declaration of energy consumption and GHG emissions of transport services (freight and passengers)

ISO 14083, Greenhouse gases — Quantification and reporting of greenhouse gas emissions arising from transport chain operations. Upcoming global standard who currently is in state: “Under publication”

Data sources

The Handbook Emission Factors for Road Transport (HBEFA) https://www.hbefa.net/
The international council on Clean Transportation (ICCT), REAL-WORLD, FUEL CONSUMPTION OF HEAVY-DUTY VEHICLES IN THE UNITED STATES, CHINA, AND THE EUROPEAN UNION https://theicct.org/
United States Environmental Protection Agency (EPA) https://www.epa.gov/
Vattenfall
Swedish Transport Administration
REDUCTION OF GHG EMISSIONS FROM SHIPS, IMO GHG Study 2020
Clean Cargo working group assessments.
Clean Shipping Index, Guidance Document, 2010
Simons, D. (1997) PIANO – Project Interactive Analysis and Optimization https://www.lissys.uk/
Hasselrot, A. (2010): Data Preparation Manual for the Flight Emission Methods Hurdy-Gurdy and Hurdy-Gurdy_GrinderXY, FOI-R-2972-SE – http://www.foi.se

Calculations in Proxio emissions

You can calculate transport emissions for both Scope 1 and for Scope 3 in Proxio Emissions. See the table below for information about accounting regarding the GHG-protocol.

Data need and considerations

Depending on the need and the availability of different data sources, Proxio emissions can be used in different ways.

Scopes of Accounting

Proxio Emissions application can be used to calculate emissions and report them according to the Greenhouse Gas Protocol. See Figure 1 - The three scopes of the Green House Gas Protocol

To capture the full impact of emissions from transports as required by the Green House Protocol, Proxio calculates emissions for the whole fuel life cycle. See Figure 2 - The Fuel Life Cycle

Well-to-Tank (WTT)

WTT emissions consist of all processes between the source of the energy (the well) through the energy extraction, processing, storage and delivery phases up until the point of use (the tank). WTT values can vary by energy source, region, method of production and the transportation required to move the fuel to market.

Tank-to-Wheel (TTW)

These are the emissions from fuels combusted to power activities (the wheel). TTW is considered to be zero for electricity, hydrogen fuel cells and biofuels – all emissions are in the WTT stages at the point of use.

Well-to-Wheel (WTW)

These are emissions from the full fuel life cycle and should be equivalent to the sum of WTT and TTW emissions.

Data sources for calculation

Primary data	Default Data	Detailed modeling
Actual data from transport operators about fuel amount and fuel type. Primary data makes the quality of the calculated emissions most accurate.	Industry average figures using standard assumptions of vehicles, road type, load factor, fuel type and empty running.	Detailed models which simulate the fuel consumption, the distance and vehicle and road properties like euro class, load factor, road gradient, etc.
By connecting primary data sources, Proxio can calculate primary data emissions.	Available for Road, Air, Sea, Train	Available for Road, Air, Sea, Train
Example: Total annual emission or average emissions per tonne-km	Example: GLEC default emission factors, NTM vehicle types, The Handbook Emission Factors for Road Transport (HBEFA)	Example: Proxio Emission customer specific modelling.

Figure 3 - Data source for calculation

Calculation models

Proxio Emissions uses different methods for emission calculations based on the data source available, see a subset of the most common models in the table below.

Model	Description
Shipment - weight	Transport of a shipment where sizing and allocation is based on cargo weight. It is assumed that shipment transports are undertaken in a shared transport system where the capacity of a vehicle (or set of vehicles) can be shared between multiple shipments. A shipment is therefore only allocated the part of the emissions that emanate from its share. The gross emissions of the vehicle are multiplied by the allocation factor to calculate the share of the shipment. Note that since allocation is based on weight alone, this can be misleading for cargo of low density.
Shipment - volume	Transport of a shipment where sizing and allocation is based on cargo volume. See "Shipment - weight" for details about general allocation principles. Note that since allocation is based on volume alone, this can be misleading for cargo of high density.
Operation - distance	Calculation of gross emissions generated when running/operating the vehicle a specified distance. No shipment is specified and no allocation is done; the system will ask for the cargo load factor but this is used for emissions calculation only (the larger the factor, the larger the emissions).
Operation - fuel	Calculation of gross emissions generated when running/operating a vehicle on a specified amount of fuel. No shipment is specified and no allocation is done; the system will ask for the cargo load factor but this is used for emissions calculation only (the larger the factor, the larger the emissions).
Passenger	Transport of people. It is assumed that passenger transport is undertaken in a shared transport system where the capacity of a vehicle (or set of vehicles) can be shared between multiple passengers or groups. A passenger (or group) is therefore only allocated the part of the emissions that emanate from its share. The gross emissions of the vehicle are multiplied by the allocation factor to calculate the share of the passenger (or group).
Passenger - passenger-km	Passenger transport, allocation and size determined by transport effort in passenger-km. See "Passenger" for details about allocation principles.
Duration /Time	Calculation of emissions when a fuel is operating in active engine time. Useful for stationary vehicles, terminal handling or transport activities where emissions are not bound to travelled distance.

Figure 4 - Calculation models

Emission factors

The emission factors that are used in calculations performed in the application are based on current science and are under constant evaluation. The work of evaluating and compiling the emissions factors is done primary by our methodology partners and then incorporated into the application. However, the system can be configured to use customer specific emission factors. There are currently three base configurations of emission factors to use:

Calculation

Scenarios

Annual emissions for fleet owners - Scope 1

To calculate emissions in Scope 1 when primary data is available (see Figure 3 - Data source for calculation); consider calculating using Operation – fuel or Operation – distance method as described in Figure 4 - Calculation models paired with Primary data as described in Figure 3 - Data source for calculation.

Consignment level with low knowledge of transport network - Scope 3

To calculate emissions for Scope 3 when you have little knowledge about the transport fleet, vehicles, fuel types etc. consider using Shipment – weight or Shipment – volume method described in Figure 4 - Calculation models paired with Default data as described in Figure 3 - Data source for calculation

Consignment level with high knowledge of transport network - Scope 3

To calculate emissions for Scope 3 when you are a large transport buyer and have good knowledge of the transport network, you already know or can easily ask for information about individual legs building up the complete route consider using Shipment – weight or Shipment – volume method described in Figure 4 - Calculation models paired with the Detailed modeling as described in Figure 3 - Data source for calculation.

Calculation process

Below diagram describes the steps and involved data during the calculation process.

Input data

Information about the transports to be calculated. Depending on the calculation model and type of data source different input data can be specified.

For primary data total distance or total fuel amount is needed.
For modelled data or default data. The calculation algorithm needs address information about origin and destination to be able to calculate the distance for the transport and weight for the shipment so that the system can allocate the emissions to the specific cargo.

Calculation

Simplified the calculation of emissions for a transport activity is done by:

calculating the distance for the transport. This depends on:
- The route which is defined by one or many legs
- Modality for each leg
calculating the total fuel amount consumed for a transport. This depends on:
- Vehicle type, engine type and euro class
- Road type and road gradient
- Distance from previous step
calculating the total emissions. This depends on:
- Emission factors for the fuel
- Total fuel amount

Distance

The distance can be provided manually as part of the input data or Proxio automatically calculates the transport distance differently depending on transport mode. The software supports all modes of transport and combines different routing services together to get the best possible accuracy in distance calculations.

Fuel consumption and road type

The calculation depends on the fuel type because of its content of carbon, sulphur and aromatic hydrocarbons. The exhaust emissions are calculated based on the fuel consumption of the selected vehicle type.

When modelled data is used, the fuel consumption for the vehicle is estimated based on data sources containing values for full, half and empty vehicles on different kinds of roads (urban, rural and motorways).

Emission factors

The system has support for GLEC, NTM and Custom emission factors. The emission factors are applied on the total fuel or energy consumed to get the output emissions.

Empty running

Empty running is a concept associated with positioning transport equipment to the next loading point. To take this into consideration the system can account for an empty travel of 17% to each road leg. This is fully customizable, but Proxio suggest it´s users to apply with the GLEC-framework of 17%.

Emissions allocation

The last step is to calculate the share of the total emission calculated in previous step that is related to the investigated shipment/cargo.

Calculation result

When the model data allows and contains relevant data, the result set will consist of at most the data set shown in the figure below.

Figure 5 - Calculation result

The Emission intensity KPI

Transport activity

Transport activity is often evaluated by the combination of weight and distance, measured in tonnekm. One tonnekm represents one tonne of cargo being transported one km.

Emission intensity

One important use for transport activity is to calculate the CO2e intensity factor (kg CO2e / tonnekm). The intensity factor describes the efficiency of transporting goods and can be used to compare the efficiency between different transport modes, routes, fuel types e