«EVERT ANDERSSON PIOTR LUKASZEWICZ Report KTH/AVE 2006:46 Stockholm, Sweden 2006 TRITA-AVE 2006:46 Department of Aeronautical and ISSN 1650-7660 ...»
related air pollution
Report KTH/AVE 2006:46
Stockholm, Sweden 2006
TRITA-AVE 2006:46 Department of Aeronautical and
ISSN 1650-7660 Vehicle Engineering
Royal Institute of Technology, KTH
Energy consumption of a number of modern Scandinavian electric passenger train opera- tions is studied. The trains are X 2000, Regina, OTU (Øresundstoget), Type 71 “Flytoget” and Type 73 “Signatur”. Energy measurements are made in regular train operations in Sweden, Denmark and Norway. For Regina and Flytoget long time series (at least one year) are available, while shorter time series are available for the other train types. Energy data for new trains (introduced since 1999) are collected in the years 2002-2005. Energy data from 1994 are used for X 2000 and are corrected for operational conditions of 2004.
For comparison, energy data for an older loco-hauled train of 1994 is also used.
In the present study energy consumption for propulsion, on-board comfort and catering, as well as idling outside scheduled service, is determined. The energy consumption includes losses in the railway’s electrical supply, i.e. the determined amount of energy is as supplied from the public electrical grid.
Emissions of air pollutants, due to production of the electric energy used, are also
determined, in this case CO2, NOx, HC and CO. Three alternative determinations are made:
(1) Pollution from average electric energy on the common Nordic market;
(2) Pollution from “Green” electric energy from renewable sources;
(3) Marginal contribution for an additional train or passenger, short-term and long-term.
The newly introduced EU Emissions Trading Scheme with emission allowances will most likely limit the long-term emissions independently of the actual amount of electric energy used by electric trains.
It is shown that the investigated modern passenger train operations of years 2002- 2005 use a quite modest amount of energy, in spite of the higher speeds compared with trains of
1994. For comparable operations the energy consumption is reduced by typically 25 – 30 % per seat-km or per passenger-km if compared with the older loco-hauled trains. The reasons
for the improved energy performance are:
(1) Improved aerodynamics compared with older trains (reduced air drag);
(2) Regenerative braking (i.e. energy is recovered when braking the train);
(3) Lower train mass per seat;
(4) Improved energy efficiency in power supply, partly due to more advanced technologies of the trains.
Energy consumption per passenger-km is very dependent of the actual load factor (i.e. ratio between the number of passenger-km and the offered number of seat-km). For longdistance operations load factors are quite high, typically 55 - 60 % in Scandinavia. In this market segment energy consumption is determined to around 0.08 kWh per pass-km. For fast regional services with electric trains, the load factors vary from typically 20 to about 40 %, while the energy consumption varies from 0.07 kWh per pass-km (for the highest load factor) to 0.18 kWh/pass-km.
However, also in the latter cases the investigated trains are very competitive to other modes of transport with regard to energy consumption and emissions of air pollutants.
i ii Preface and acknowledgements This energy study was initiated in an agreement between Bombardier Transportation and the Royal Institute of Technology (KTH) in Stockholm. It is a “follow-up” and continuation of a similar energy study made at KTH in 1994. The main part of the study has been made at KTH, using energy data supplied from various sources.
First of all the personal and financial support from the Centre of Competence “Design for Environment” at Bombardier Transportation is gratefully acknowledged. In particular we would bring our thanks to Mrs Christina Larsson, Mrs Sara Paulsson and Mr Peder Flykt for their enthusiastic and very valuable personal support in supplying energy data from Regina and X 2000 trains and in their efforts to arrange the necessary contacts with train operating companies in Scandinavia.
We also thank Mr Stefan Christensson at Flytoget AS in Oslo, as well as Mr Ståle Ansethmoen at NSB, Oslo, and Mrs Rikke Naeraa at DSB in Copenhagen for their contributions to energy data and actual load factors. Marie Hagberg at SJ AB in Stockholm has supplied information on “green” electric energy.
Mr Anders Bülund at Swedish National Rail Administration (Banverket) for providing statistics and efficiency data on the Swedish converter stations.
For supplying data on electric power production we would also like to acknowledge Mr Gunnar Wåglund at Svenska Kraftnät and Mr Gunnar Hovsenius at Elforsk AB.
Finally, we would like to thank Mr Göran Andersson and Mr Anders Jönnson at the Swedish Energy Agency (Energimyndigheten) for helpfull discussions about the nordic power market, production and marginal power.
Stockholm in June 2006
x 1 Introduction Rail transport is widely considered to be energy efficient compared to most other modes of transport. By consuming just a moderate amount of energy, there are also prospects of low emissions of pollutants into the air, such as carbon dioxide (CO2), nitric oxides (NOx) and others. The possibilities to use electric power further strengthen this tendency, because electric power may be produced by a number of means, some of them with very low air pollution, if any. Low energy consumption and air pollution are often considered as being competitive advantages of rail traffic, together with high safety, comfort, high capacity and space efficiency as well as – for modern rail systems – travelling speed.
In 1994 a study was made by KTH (Royal Institute of Technology, Stockholm, Sweden) on energy consumption and air pollution in Swedish electric rail traffic . Different types of trains were investigated through electric energy measurements in various types of passenger and freight services. An estimation of future development (year 2010) was also made.
Since that time a number of new modern passenger trains have been introduced in Scandinavia (Denmark, Norway and Sweden), mainly with electric propulsion and to a small extent also with diesel propulsion. Also the services of the high-speed train X 2000 have been further developed. However, no update of energy and air pollution studies is known since the previous study in 1994.
The present study is initiated by Bombardier Transportation (Sweden). This company has supplied the majority of new trains for Scandinavia during the period 1994 – 2004. For example, by the end of 2004 the following numbers of electrically powered passenger
vehicles were delivered for main line rail operations:
224 cars of the high-speed tilting train X 2000 as well as 43 power units of the same train for the Swedish rail operator SJ AB (partly delivered before 1994); see Figure 1-1.
- 148 cars of the fast regional trains Regina for Swedish domestic services;
see Figure 1-2.
168 cars of the fast regional trains for the Øresund link between Denmark and Sweden;
see Figure 1-3. These train units are often called OTU (Øresund Train Unit).
- 48 cars of the trains Type 71 for Gardermoen airport outside Oslo in Norway, also called Flytoget, running airport shuttles between Gardermoen, Oslo and Asker; see Figure 1-4.
- 88 cars of the long-distance tilting trains Type 73 earlier called Signatur and the fast regional trains Type 73b earlier called Agenda for domestic Norwegian services operated by NSB; see Figure 1-5.
All of these cars are four-axle vehicles each having a length of 25 – 27 m. All the trains have a permissible speed ranging from 180 to 210 km/h. They have all air condition.
X 2000 has a bistro (about half a car) as well as the Norwegian Signatur trains. Both X 2000, Signatur and Agenda have carbody tilt, in order to allow increased speeds in curves.
The OTU is able to run on both the Danish and Swedish signalling and electrification systems. In Sweden the electrical supply system has a nominal voltage of 15 kV at 16 2/3 Hz. The Danish electrified main lines have a nominal voltage of 25 kV at 50 Hz.
Further train data are given in Figures 1-1 to 1-5.
1 Figure 1-1 High-speed train X 2000 Power unit + 5 cars + driving trailer Number of seats, 1+2 class, 98+222 =320 Max speed in service 200 km/h Mass in running order 366 tonnes Figure 1-2 Fast regional train “Regina” 2 motor coaches (alternatively with 1 intermediate trailer) Number of seats, 1+ 2 class, 19 + 148=167, (alt. 19+ 253=272) Max speed in service 200 km/h Mass in running order 120 (alt. 165) tonnes (Numbers within brackets refer to the 3-car version with an intermediate trailer)
Figure 1-4 Airport train Type 71 “Flytoget” 3 motor coaches Number of seats, 2 class = 168 Max speed in service 210 km/h Mass in running order 168 tonnes Figure 1-5 Long distance train Type 73 “Signatur” 3 motor coaches + 1 intermediate trailer Number of seats, 1+ 2 class = 201-227 Max speed in service 210 km/h Mass in running order 233 tonnes 3 Scope and limitations of this study The scope of the present study is to determine average energy consumption and the related emissions of air pollutants of representative modern trains in passenger service in Scandinavia. All the trains studied are supplied by Bombardier Transportation. Some comparisons will also be made with older train services and – to some extent – with other modes of transport.
In order to achieve a figure on average energy consumption – and/or its related air pollution – either measured or simulated energy consumption data are needed, per train-km or per seat-km. It is also of interest to convert these data into energy or pollution per passengerkm. The latter conversion is possible only if the average load factor, i.e. the seat occupancy rate, is known. The load factor is here defined as the number of passenger-km divided by the number of offered seat-km.
Energy consumption and its related air pollution, as determined per seat-km, has a large variation over time for a specific type of train, due to the actual speed or the number of stops. If determined per passenger-km there is also a variation due to the actual load factor.
However, it is not the aim of this study to determine energy or pollution data for all possible cases. In this study a number of train services have been selected, all being believed to be representative for the respective types of railway mainline passenger services on average. The characteristics of these services are presented and discussed in Sections 3.2 - 3.6.
A train with electric propulsion consumes energy being produced in some kind of electric power plant. In order to determine the air pollution, indirectly resulting from the electric power production and consumption, the means of electric power production is decisive.
Electricity can be produced by means of - for example – hydropower, nuclear power, wind power or some kind of bio-fuels. Electric power can also be produced by fossil fuels like coal, oil or natural gas. The efficiency and energy losses – as well as emissions of air pollutions - in fuel-burning power stations may vary over a quite large range depending on the technology used and whether heat (for district heating or industrial use) is produced or not. The present study also discusses these issues in Sections 2.3 – 2.5.
4 2 Structure of railway electric energy consumption and its related air pollution
2.1 Structure of energy utilization on railways 2.1.1 Various purposes of energy consumption There are various purposes of using energy on railways and in train operations. We propose energy consumption in train operations to be divided into eight different purposes as shown in Table 2-1. The table is particularly adapted to electric train operations, i.e. the case where electric power is taken from an overhead electrical cable - usually called catenary – through the current collector – called pantograph – for use in an electrically powered rail vehicle.
1 Propulsion including auxiliary machinery and the necessary safety systems
3 Idling outside scheduled service 4 Stationary vehicle heating at parking on stabling tracks
- through the ordinary pantograph (i.e. the current collector) or
- through a special stationary “heating terminal”, to be connected to the train
7 Operation and maintenance of fixed installations not including heating of premises 8 Heating of buildings and other premises serving the rail transportation system
In this study energy consumption is determined for purposes 1 – 3. In some cases energy for stationary heating at parking (purpose 4) is included in the measured raw data. In such cases energy for purpose 4 is estimated and excluded from reported energy consumption.
Energy for purposes 5 – 8 is not regarded at all in this study.
As a transportation system, the railways thus require more available functions than the actual propulsion and hauling of vehicles. Naturally, this also applies to other modes of transport: road, air and sea transportation.
5 Below are some examples, comments and comparisons given of the various purposes as listed in Table 2-1, for electric rail transportation as well as the corresponding road traffic.
The examples presented are, however, not claimed to be a comprehensive list.
Heating, lighting and ventilation are included in the energy consumption reported for trains in this study.
Reported energy consumption of trains also includes carbody tilt equipment as well as haulage and operation of restaurant cars where applicable (in the present study for the trains X 2000 and Signatur).