Energy and CO2 emissions

The global railway sector is working extremely hard to maintain its environmental advantage by improving its energy efficiency and reducing its CO2 emissions. For example, 28 European members of UIC have collectively committed to reduce CO2 emissions per passenger kilometer and ton/kilometer by 50% by 2030, and are well on track to meet this target.

Improving energy efficiency is the most important aspect of the railway’s strategies to reduce CO2 emissions, and of course has significant business benefits by reducing costs.

Railway companies use a combination of technical and non-technical means to improve energy efficiency. Technical measures include using more modern rolling stock with lower energy consumption, or innovative technologies such as regenerative braking – a system that harnesses the energy produced during braking, transferring it back into the rail system, allowing other trains to use it.
Non-technical measures include energy-efficient driving techniques, which focus on developing train drivers’ expertise to save energy or diesel fuel costs. Linked to both these points is the installation of clear Energy Metering on trains, so that operators can monitor their energy consumption and assess which approaches save the most energy.

Environment Strategy Reporting System (ESRS)

Methodology and Policy

UIC and CER General Assemblies, in order to provide a unified approach to environmental and sustainability topics for the European railway sector, voted in December 2010 the document “Moving towards Sustainable Mobility: Rail Sector Strategy 2030 and beyond – Europe (UIC-CER 2010)":

The strategy outlined in the document describes how the rail sector should be performing in
environmental terms in 2030 and 2050 and it is built on four key environmental topics: climate protection, energy efficiency, exhaust emissions and noise. It sets out specific objectives to be met by 2030 and, as uncertainties make prediction for the longer timeframe of 2050 more
difficult, more general “visions” for 2050.

Data are regularly collected and stored on the website:

The tool gives also a yearly update data to “Ecopassenger” and “EcoTransit”, the UIC-developed ecocalculators.

UIC-IEA Railway Handbook: Energy Consumption and CO2 emissions of World Railway sector

It represents a unique source of direct data of the railway sector verified and consistency checked by the IEA. The aim of the Handbook is to provide institutions, associations and decision-makers with robust key performance indicators as the foundation on which to build the greening of our future transport choices.

2016 publication marks the fifth year of cooperation between the two organizations and aims at providing insightful information, each year covering a special feature. In the past, these topics have ranged from the energy mix in the rail sector to the cost and sustainability impacts associated with rail infrastructure to vehicle efficiency. The new edition takes into account the Paris Agreement, the historic outcome of the 21st UNFCC Conference of Parties (COP21) in December 2015 in which more than 180 countries pledged to take steps to reduce greenhouse gas emissions.

Part I of the Handbook is dedicated to presenting the most significant data and trends concerning energy consumption and CO2 emissions from the rail sector, focusing on the most relevant Regions in terms of rail activity, namely EU 28, USA, Japan, Russia, India and China. This serves to place a spotlight on the regions and countries which cumulatively accounted for 89% of passenger-kilometres and 84% of tonne-kilometres travelled globally in 2013. In addition, statistics illuminating rail-related CO2 emissions, passenger activities, freight activities, and electrification rates at a regional and global level are published within this section.

The transport sector emitted 7.5 billion tCO2 in 2013. The share of CO2 emissions from transport has continuously increased since 2010 from 22.7% to 23.4% in 2013. In 2013, 3.5% of transport CO2 emissions were due to the rail sector, while railways transported 8% of the world’s passengers and goods.

Part II of 2016 handbook emphasizes the analysis and the evaluation of rail sector and national targets, also compared to other modes of transport. The results of our analysis indicate that historical evolution of specific energy consumption and specific CO2 emissions from rail are on track to achieving the 2030 and 2050 UIC Low Carbon Rail Transport Challenge targets, moving the rail sector towards the 2 Degree Scenario (2DS) outlined in the IEA Energy Technology Perspectives (ETP) publication. The Handbook presents for the first time the evolution of the rail global targets set by UIC in 2014, supported by the outcomes of the commitment on reporting signed in 2015 by UIC Members through the Climate Responsibility Pledge inside the ‘Train To Paris’ campaign.

The rates of improvement of rail energy and CO2 intensity were in line with the 2030 and 2050 targets in 2013 (latest collected data): specific energy consumption has reduced by 37% between 1990 and 2013, and specific CO2 emissions have reduced by 30% in the same period, according to the IEA Mobility Model, integrating energy consumption data of UIC members covering over 90% of total rail activity.

The special focus on sustainability targets in this handbook delivers a clear message to the audience: rail transport offers a more sustainable alternative to most other transport modes, both in terms of energy use and carbon emissions per passenger-kilometre or tonne-kilometre, and is anticipated to continue to do so over the coming decades.

Energy Billing Project

More and more traction units in Europe are equipped with metering systems collecting data regarding energy consumption and the positions of the traction units. To avoid different metering systems being installed according to national specifications it is necessary for cross-border traffic to standardise the exchange of data. In this light the Energy Billing Project was set up in October 2005 in order to ensure an exact billing of energy consumption for interoperable cross-border rail traffic in Europe.

Together with the standardisation of the metering equipment by CENELEC the results of the Energy Billing project will enable rail operators to pay the energy bill according to the actual energy consumption only.

UIC leaflet 930

The Energy Billing Project has elaborated the UIC leaflet 930 “Exchange of data for cross-border railway energy settlement”. The leaflet was published in November 2009.

The purpose of the UIC leaflet 930 is to:

  • Describe the processes and protocols used for the exchange of energy consumption data between Infrastructure Managers which by respecting existing national systems thereby contribute to an improvement in European railway sector interoperability.
  • Define the technical requirements for the checking and verification of this data.
  • Allow Railway Undertakings to identify their genuine energy consumption and therefore pay exactly what is consumed; associate the consumption of each train to the bill and the energy price (including existing models) which will lead finally to energy savings.

Supporting documents to UIC leaflet 930

The Energy Billing Project has elaborated the following supporting documents to the UIC leaflet 930, which will support the implementation of Energy Billing Systems.

  1. Supporting document 1: Border points and polygons
  2. Supporting document 2: Estimation systems for un-metered trains
  3. Supporting document 3: Right of access to the consumption data by Railway Undertakings and Public Information provided by Infrastructure Managers

This leaflet establishes the necessary framework for the exchange of data for cross-border railway energy settlement. You can find it at

Zero Carbon Railways

How to report green electricity use?

Recent data showed that European railways used in 2009 nearly 30% of renewable electricity, with a significant increase in the last years (See UIC/IEA Railway Handbook 2013 e link). Decarbonization of electricity mix is one of the drivers for CO2 emission reduction: the higher the percentage of electricity from renewable sources used for traction, the lower is the CO2 emitted in the atmosphere.
In parallel to the growth in renewable energy production, the voluntary use of renewable electricity by companies has also been growing at fast pace.

Therefore definining a transparent methodology for tracking tracking green electricity purchasing became fundamental for the UIC Environment Strategy Reporting System ..

This report is the result of an intense year working spent on consulting related stakeholders (IEA, EEA, DG Energy…) and UIC Experts from the Energy Efficiency and CO2 Emissions in order to agree on a common approach when reporting on Carbon performance internally and at sector level (ESRS).

The conclusion of the report suggests highlited the importance of using both he electricity mix and the market-based mix.

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