Energy Management in the Railway Industry: A Case Study of
Rail Freight Carrier in Poland
Aleksandra Kuzior 1and Marek Staszek 2,∗
Citation: Kuzior, A.; Staszek, M.
Energy Management in the Railway
Industry: A Case Study of Rail
Freight Carrier in Poland. Energies
2021,14, 6875. https://doi.org/
Academic Editors: David Borge-Diez
and Victor Manuel Ferreira Moutinho
Received: 14 July 2021
Accepted: 15 October 2021
Published: 20 October 2021
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1Department of Applied Social Sciences, Faculty of Organization and Management, Silesian University of
Technology, ul. Roosevelta 26, 41-800 Zabrze, Poland; firstname.lastname@example.org
2DB Cargo Polska S.A., ul. Wolno´sci 337, 41-800 Zabrze, Poland
Energy is crucial to economic development, but its production usually has a negative
impact on the environment. This ambivalence leads to the need for methods to improve energy
efﬁciency. Transportation is one of the largest global energy consumers. Therefore, improving the
energy efﬁciency of transportation is crucial for sustainable development. The aim of this article
is to show the limitations of energy management in railways, resulting from the model of market
regulation. The question in this context is whether only technological methods can be used in
railways to steer its energy efﬁciency, as is suggested by the existing research. Critical analysis, desk
research and a case study of Polish railway undertaking were used to ﬁnd an answer to the research
question. The discussion of the results shows that the European regulatory system leads to greater
complications in the ﬁeld of energy management than in other global regions, where railways are
also important for the economy. Due to these limitations, rail operators use indirect methods to
measure energy efﬁciency. Results indicate that although energy efﬁciency improvements are being
achieved, they are mainly due to organizational measures and not technological ones as could be
expected based on previous research.
Keywords: energy efﬁciency; transportation; railway transportation
Energy is essential for economic and social development, as well as for improving the
quality of life. We could no longer imagine the modern world without access to energy.
Ensuring energy security has become one of the fundamental tasks facing governments of
individual countries. The increasing demand for energy on the one hand and dwindling
resources of non-renewable energy sources on the other results in the need to acquire energy
from alternative sources and to increase efﬁciency of energy consumption in various areas
of the economy, agriculture and social life as well as appropriate energy management.
Energy efﬁciency is deﬁned broadly as the ratio between output, services, goods or energy
and energy input (Directive 2006/32/EC) [
]. Energy efﬁciency should be considered in the
wider context of sustainable development. Global Action Agenda 21 (1992) [
document constituting the concept of sustainable development—deﬁnes major courses of
action to improve energy efﬁciency in business, agriculture, transport and other areas of
One of the primary goals identiﬁed in Agenda 21 is to reduce the atmospheric impact
of the energy sector by developing environmentally friendly and economically viable
energy systems, based on renewable and clean energy sources, aimed at less pollution and
more efﬁcient generation, transmission and distribution of energy. The changes should be
based on research into innovative green technologies and the transfer of environmentally
friendly energy technologies to developing countries. Agenda 21 also envisages increased
capacity for energy planning and management of an energy efﬁciency programme. Ground-
breaking in its proposals to double prosperity while halving natural resource consumption
Energies 2021,14, 6875. https://doi.org/10.3390/en14216875 https://www.mdpi.com/journal/energies
Energies 2021,14, 6875 2 of 21
was the report “Factor Four”, prepared for the Club of Rome [
]. The authors of the
report argued that the Factor Four revolution is necessary and technologically viable [
Nowadays, many of the solutions described in the report have already been implemented,
although we still have not achieved satisfactory results.
Another report prepared for the Club of Rome, entitled “Factor Five. Transforming
the Global Economy through 80% Improvements in Resource Productivity”, was also
developed by a team of specialists led by E. U. von Weizsäcker and published in London
in 2009 [
]. “Factor Five” is a certain complement and extension of “Factor Four ”. Based
on the assumptions of “Factor Four”, the authors show that there is a real possibility to
achieve a ﬁve-fold improvement in resource productivity in key sectors of the economy,
i.e., construction, transport, industry and agriculture.
The ﬁrst decade of the new millennium brought various technological solutions that
enabled the implementation of energy-efﬁcient solutions. The awareness and approach
of entrepreneurs to environmental protection issues has also changed. As indicated by
the report entitled “The Business Case for the Green Economy. Sustainable Return on
], the development of green economy sectors (renewable energy, increased
energy efﬁciency, rational waste management, reforestation, development of integrated
water management, reclamation of dry areas and sustainable agricultural development)
has taken place. The report’s conclusion is that the green economy represents a business
opportunity, and green investments not only pay for themselves but also enable them to
succeed in the market. The report provides examples of positive rates of return on green
economy investments and shows that green investments are not only ﬁnancially proﬁtable,
but they also strengthen brand value and build a positive reputation of the company, which
in turn translates into ﬁnancial proﬁts [
]. The issue of energy efﬁciency is present in
almost all documents constituting the concept of sustainable development and programme
documents of the European Union. Attention is drawn to the issue of scientiﬁc advice to
decision makers in the area of sustainable development management and implementation
of energy-efﬁcient technologies [
]. Energy efﬁciency has also been the subject of research
and scientiﬁc consideration for many years.
In the context of energy efﬁciency, numerous topics are addressed in the literature,
such as: issues related to green energy [
], and renewable energy sources [
] or the use of biofuels [
]), clean technologies for obtaining energy
from coal [
], optimization processes for obtaining energy from natural gas [
], a variety
of chemical reactions in the combustion of heavy fuel oils [
], as well as processes for
reducing CO2 and other greenhouse gases [19,20].
Compared to the previous research, in this article, we take a broader perspective and
include the inﬂuence of regulatory framework of railways as well as organizational mea-
sures that can be implemented in railway undertakings in order to steer energy efﬁciency
in this industry. The expected conclusion may be valuable for business as well as policy
makers. The legislative perspective gains a special meaning nowadays, as the United
Kingdom after having left the European Union is announcing revision of their regulatory
framework and renationalization of railways.
There is also a growing number of articles that discuss the use of mathematical
tools, numerical tools, artiﬁcial intelligence, and cognitive technologies to support energy
efﬁciency improvement [
], energy management processes [
] as well as the
role of managers in the management of energy supply companies [
]. Studies on energy
management are quite numerous.
Railway companies are usually described in scientific literature from the perspective of
economic efficiency [
], environmental efficiency [
], digital transformation of transport
] or railway transport safety [
]. It is certainly a worthwhile idea to adopt
solutions based on cognitive technologies and artificial intelligence [
] in the management
processes of railway enterprises and use them for energy efficiency programming.
There are only a few studies on energy efﬁcient railway companies per se; nevertheless,
the authors emphasize the need to use innovative solutions to increase energy efﬁciency.
Energies 2021,14, 6875 3 of 21
They point out, for example, the need to add the topology of the electric system to the
data considered when designing the train trajectory [
], to use more efﬁcient thyristor
control algorithms [
], to improve the performance of the train control system using
artiﬁcial intelligence technologies, deep reinforcement learning and imitation learning [
to identify the value of features that reduce energy consumption using Artiﬁcial Intelligence
Rail is considered as a low-carbon transportation mode. Besides the high level of
electriﬁcation, energy efﬁciency in rail transport is one of the main reasons for the low
carbon footprint of rail [
]. Railway infrastructure is perceived as a system good, con-
stituting a natural monopoly. Therefore, to ensure market conditions for the use of this
infrastructure, it is necessary to use at least partial mechanisms of regulation. Models of
regulation, introduced in different countries, inﬂuence energy management in railway
undertakings. The aim of this article is to show the limitations of energy management in
railway companies, resulting from the adopted model of market regulation and to indicate
the practical methods used by the participants in this market to improve their energy
efﬁciency and to obtain a positive environmental effect.
The deregulation of railways in Europe was intended to eliminate monopoly and
introduce market mechanisms. One of the main mechanisms of this deregulation, vertical
separation, is the separation of infrastructure managers from carriers. In conjunction with
the fragmentation of the railway system in Europe, it caused considerable complications in
the accounting of traction energy supplied to individual operators in individual European
Union countries. This hindered action aimed at improving the energy efﬁciency of railways
and individual railway companies operating in the deregulated market. It also caused
complications in the creation of a common European railway area, postulated by the
European Union. Previous research in the ﬁeld of railway energy efﬁciency has focused on
technical aspects. The importance of activities related to the organization of the transport
process and the rolling stock maintenance system was not revealed. We believe that such
activities have a signiﬁcant impact on improving the energy efﬁciency of the railway
operator. The effects of the railway regulatory model and its implementation in the
European Union countries on the energy efﬁciency of the railway system, as well as
practical problems arising during the construction of a single European railway area,
were also not revealed. This article, using the case study presented by DB Cargo Polska,
contributes towards closing the research gap in this regard.
2. Materials and Methods
The issue of energy management in rail transport is presented using a case study due
to its complexity and heterogeneity.
A case study is an empirical inference about a contemporary phenomenon in its natural
context. The method allows answers to the research questions “how?” (e.g., how something
is organized) and “why?” (e.g., why certain actions are taken). In-depth analyses also allow
for a thorough understanding of the described phenomenon [
]. A comprehensive ap-
proach was adopted, based on observation, analyses of internal documentation, statistical
data and other available source materials. Desk research analyses were also conducted,
referring to public statistics documents, reports, qualitative analyses and publications.
The case study is preceded by the analysis of the situation of the railway industry in
the world, Europe and Poland, where the company being the object of this study operates.
This analysis contains elements of comparison of conditions and the way the railway
industry is organized in particular geographical regions. These factors are important for
the differentiation of energy efﬁciency between particular regions. The taxonomy used
by the UIC—International Union of Railways—is adopted. The UIC is an international
professional association of railway companies, and its statistics enable comparison of data
concerning railways in different regions of the world, where rail plays an important role in
Energies 2021,14, 6875 4 of 21
The choice of UIC statistics provides an appropriate context for railway performance
in Europe, which is a region where railways have their historical roots and have developed
intensively since the beginning of the 19th century [
]. The UIC data were obtained from
UIC reports and studies available online. They mainly relate to operational parameters.
UIC statistics are a valuable source of information due to the systematic presentation
related to the importance of railways for the economy. For infrastructure data, publicly
available data from Worldstat and Eurostat were used to show the level of development of
the railway network. They better reﬂect the global diversity of the railway network.
Our analysis also includes a comparison of energy efﬁciency aspects of rail transport
globally with its main competitor, road transport. UIC data were used in this regard, due
to the operational nature of these data.
With respect to railways in Poland, the analysis presents the development path of the
railway industry after the liberalization of the market in this country and the operating
conditions of companies, which, like the case study subject, are engaged in rail freight
transport. To conduct these analyses, a literature review was used.
As we show in the analyses conducted in this chapter, rail is a mode of transportation
whose global environmental impact is relatively small. The diversity of the rail network
in global regions, the level of technological development, and speciﬁc market regula-
tions result in signiﬁcant variation in energy efﬁciency and energy management methods
3.1. Railways in Europe Compared to Other Regions
According to data published by the International Union of Railways (UIC) [
transport globally accounts for less than 2% of transport energy consumption, which is
about 0.5% of the total global energy consumption, with rail’s modal share being about
7%. Rail is in a much better position in terms of energy efﬁciency than road transport,
which is its main competitor in land transport. Road transport accounts for more than
75% of the total energy used in transport and its modal share is only 35%. If we assume
that the share of energy consumption represents the input and the modal share represents
the output of the system, then the global energy efﬁciency of rail can be evaluated in this
perspective as almost eight times higher than the efﬁciency of road transport. It should
also be noted that rail transport has signiﬁcantly improved its energy efﬁciency in recent
decades, as indicated by data published by the UIC on decreasing unit energy consumption
on rail [
]. The density of the railway network in Europe is relatively high [
], as shown
in Figure 1. This has several structural effects that affect how railways in Europe operate
and how efﬁcient they are. High network density results in numerous nodes and short
line lengths [
]. On the other hand, high network density favors the development of
intermodal transport, in which rail can play an important role by offering easy access to
transshipment terminals .
In addition, the European railway area is divided by numerous national borders,
which, given the diversity of infrastructure in terms of power supply to the catenary
network as well as signaling and safety systems, and in some cases the rail gauge, generates
additional constraints on railway trafﬁc in Europe [
]. Comparing Europe, based on
data published by UIC, to other regions where rail plays a signiﬁcant role in the transport
], some interesting conclusions can be drawn. The modal share of rail is relatively
small in Europe. It amounts to 8% for passenger transport and 12% for freight transport.
As can be seen in Figure 2, the modal share of freight rail transport in the Russian Federation
is as high as 88%, and the modal share of passenger transport in Japan is 30%. On the other
hand, in the USA, the modal share of railway for passenger transport is less than 1%.
Energies 2021,14, 6875 5 of 21
Density of railway network in km of railway lines per 1000 km
. Own study based on data
An important distinguishing feature for railways in Europe is the share of renewable
energy in its energy mix. Europe compares best with other regions in this regard. However,
Figure 3shows that the total share of electricity in the rail energy mix is the highest in Japan.
In 2011, the European Commission published a White Paper entitled "Roadmap to a
Single European Transport Area" towards a competitive and resource-efﬁcient transport
system. The paper calls for the creation of a transport system that will enable a 60%
reduction in greenhouse gas emissions by 2050 [
]. According to the report "Electriﬁcation
of the Transport System" published by the European Commission, one of the important
factors enabling the achievement of environmental goals set by the White Paper is the
reduction of unit energy consumption by rail transport by 30% by 2035 .
Commonly used measures of operational performance in rail transport are tonne-
kilometers, abbreviated as tkm and calculated as the product of weight and distance of
goods transport, and passenger-kilometers abbreviated as pkm and calculated analogously
as the product of the number of passengers and transport distance. In relation to these
performance units, expressing the output of rail transport, energy efﬁciency is calculated as
the ratio of energy consumption in a given period to operational performance achieved in
this period, expressed in tkm for freight transport, and for passenger transport, expressed in
pkm. The summary below in Figure 4shows how Europe is doing with its energy-efﬁcient
rail targets compared to the achievements of other regions.
Energies 2021,14, 6875 7 of 21
Change of unit energy consumption in the rail industry in selected regions in 2015 vs. 2005.
Own study based on data from .
The progress in railway energy efﬁciency achieved by Europe was on a par with the
progress in the USA and Japan. A signiﬁcant increase in speciﬁc energy consumption in rail
passenger transport in China can be explained by the dynamic development of high-speed
rail in that country.
The following factors can be a source of energy efﬁciency improvement on the railways
within the existing network [56–58]:
• reduction of the speciﬁc energy consumption of the traction vehicle while driving;
• reduction of the energy consumption of the traction vehicle during standstill;
• improvement of train driving technique by staff;
optimization of the timetable on the electrified network in order to balance the network load;
optimization of the rolling stock maintenance system, resulting in a reduction in
reduction of energy used for the maintenance of the railway network and railway
Improving energy efﬁciency in individual regions can be achieved with very different
methods, due to the different energy sources used in these regions, which is shown in
Figure 3. In the USA, diesel traction is dominant. Actions aimed at improving energy
efﬁciency may include the technical development of the existing internal combustion en-
gines and the improvement of the technique of driving a combustion traction vehicle [
The importance of such activities for railways in Japan is marginal due to the dominant
electric traction there [
]. In turn, factors such as reducing energy consumption through
regeneration or optimization of timetables aimed at equalizing power consumption will
be of great importance in Japan [
]. In this context, the railway in Japan is similar to the
underground railway, which, operating in a closed system, allows the use of mathematical
algorithms for optimizing the timetable to improve energy efﬁciency [
]. The European
rail network lacks the advantages of both American and Japanese railways. There is a
large diversiﬁcation in the ﬁeld of energy sources, which means that sources of improving
the energy efﬁciency of traction vehicles should be sought in the development of electric
machines and internal combustion engines. Due to the high fragmentation of the infras-
tructure and the diversiﬁcation of the power grid, optimization in terms of timetables is
currently not a practical possibility.
Energies 2021,14, 6875 8 of 21
The railway market in the European Union countries has been undergoing a process
of deregulation since the 1990s. Previously, railway in individual European countries were
organized as single monopolistic companies, controlling both infrastructure and railway
transport. However, the deteriorating position of railway in inter-modal competition with
road transport and the worsening ﬁnancial condition of railway companies have led the
European Commission to take action aimed at revitalizing the railway and to search for
solutions introducing intra-modal competition in order to optimize use of the railway
infrastructure in Europe [
]. Elimination of the monopoly in railway transport turned out
to be a challenging task. The applied solution assumes the existence of system goods, which
are the subject of a natural monopoly [
]. In the case of the railway, the infrastructure is
considered to be such a goods system [
]. European deregulation of the railway market is
based on vertical separation, i.e., separation of operators (i.e., companies which operate
railway transportation) from railway infrastructure managers and establishment of rules of
free access of operators to infrastructure (still managed as a natural monopoly). In addition
to vertical separation, the deregulation of the European rail market has resulted in a
horizontal separation, which is based on separation of freight and passenger operators,
for which the regulations that are introduced assume separate licensing of operations.
The separation of infrastructure within the framework of vertical separation referred to
track infrastructure, along with related signaling, command, control and safety systems. It
also referred to the railway electriﬁcation system and its power supply system.
The Directive on Railway Vertical Separation was issued in 1991 [
]. The ﬁrst rail-
way package, announced in 2001, gave guidelines for the allocation of railway network
capacity and charges for access [
]. Since then, rail market reforms have been successively
implemented in the member states, and successive packages have introduced detailed
regulations for rail transport in Europe, as shown in Figure 5below [68,69].
European legal acts on the deregulation of the railway market. Own study based on [
By way of comparison, it should be added that the model of railway market deregula-
tion adopted for restructuring in the U.S. does not include the vertical separation, which
is the basic principle of European deregulation. The American model is based on geo-
graphical separation, separating individual segments of the railway network in such a way
that they are operated essentially by one operator. This model assumes that a particular
network is operated by a single operator and that competition occurs between alternative
networks offering connections between different regions of the country [
]. This choice
was inﬂuenced by several factors that differentiate the American rail system from the
European one. The lower network density, dominant private ownership of infrastructure,
Energies 2021,14, 6875 9 of 21
lack of the technical differentiation characteristics as well as the liberal approach of the
governments in Europe resulted in the fact that rail regulation, introduced by the Railway
Revitalization and Regulatory Reform Act of 1976 and the Staggers Rail Act of 1980, only
concerns the obligation imposed on railway operators to treat shippers using their rail
transport services in a non-discriminatory manner.
Taking into account the vertical and horizontal separation of the railways in Europe,
the effects of which were deepened by the emergence of numerous new players on the
railway market as well as the diversity of the systems of power supply to the railway
network among the individual countries of the European Union and often also within
those countries, the problem of accounting for the consumption of electric power supplying
the railway network is not a trivial one. On the one hand, in a locomotive connected to a
train, which travels between different power supply areas, the propulsion system must be
switched. Thus, the locomotive sequentially receives power from different networks during
a single journey. On the other hand, multiple locomotives belonging to different operators
operate simultaneously in a homogeneous network area. The power consumption of the
network has to be accounted for by multiple consumers. Furthermore, the decisions regard-
ing the timetables are taken by the infrastructure manager, which limits the possibilities
of the electric network manager to optimize energy consumption by balancing the power
demand over time.
Before the deregulation of railways in Europe, this problem did not occur on such a
large scale because monopolistic state-owned companies managed both the infrastructure
(including the track system and the power supply network for trains) and operations on this
network. Thus, there was no need to account for energy between sub-entities. Deregulation
conducted according to the U.S. model avoids the problem of complex energy billing
because the model still has only one operator on a segment of the network. Locomotives
manufactured before the deregulation of railways in Europe were generally not designed
for direct energy metering. Taking into account the life cycle of these vehicles, which is
often 40 to 50 years, for the next few decades we can expect to see locomotives equipped
both with and without metering devices on the European rail network. The issue of
standardization of on-board devices, measuring the energy consumption on the locomotive
and recognition of their measurements by individual managers of the railway power
network, still remains the subject of efforts of both the European Railway Agency (ERA)
and organizations associating managers of railway infrastructure [71–73].
3.2. Railways in Poland Compared to Other European Countries
The railway network in Poland, according to the Ofﬁce of Railway Transport (UTK),
which acts as the regulator in the country, had a length of 18,934 km in 2019, 61% of which
are electriﬁed lines [
]. After Germany and France, Poland thus has the third largest rail
network in Europe. The network density in Poland according to UTK data reaches the
value of 62 km per thousand square kilometers. According to Eurostat data, the modal
share of rail in Poland for passenger transport in 2017 was 7.7%. As Figure 6below shows,
this share places the Polish railway at a level close to the European average, which for the
EU28 countries was 8% .
The modal share of rail in Poland for freight transport in 2017 was 26.8%. As Figure 7
below shows, this gives the railway in Poland a position well above the average for EU28
countries in this respect .
Energies 2021,14, 6875 10 of 21
Modal share of railway transportation in passenger transport for selected European
countries in 2017. Own study based on data from .
Modal share of railway transportation in freight transport for selected European countries
in 2017. Own study based on data from .
Such a high modal share of rail transport in freight transport in Poland, compared to
other EU28 countries, is mainly due to bulk coal transport in the country, which reﬂects the
role of this raw material in the Polish energy mix. Given the scale of coal haulage in Poland,
competition from road transport is limited in this respect. The negative dynamics of the
modal share of rail in the freight market shown in Figure 8below indicates that rail is not
beneﬁting adequately from the economic development of the country. The effects of this
development, in the form of an increase in freight transport, are consumed by other modes
of transport, mainly road transport. The modal share of railway in passenger transport has
remained constant during this period [75,76].
Energies 2021,14, 6875 11 of 21
Dynamics of modal share of railway transportation in Poland. Own study based on data
The demonopolization of the rail market was introduced in Poland in 2003. The law
governing the railway market was preceded by the Act on the Commercialization, Restruc-
turing and Privatisation of the State Enterprise Polskie Koleje Pa´nstwowe (Polish National
Railways—PKP), passed in 2000. On this basis, the former monopolist was restructured and
adapted to the requirements of the European directives contained in the ﬁrst railway pack-
age. In Poland, a holding model has been adopted, in which the infrastructure manager and
the operators that formerly constituted the state monopoly are transformed into capitalized
companies but remain integrated within the holding company, which exercises ownership
functions over those companies. A similar model, but with varying levels of coordination
within the holding company, was used in the deregulation of railways in Austria, France,
Germany, Italy, Belgium, Slovenia and Latvia [
]. In 2015, a decision was made to sell
PKP Energetyka, a company belonging to the PKP holding, to the American fund CVC
Capital Partners. After the approval of the European Commission, the transaction was
], and thus, the management of the power grid, supplying the railways in
Poland, was entrusted to a private company. Competition on the Polish railways appeared
as early as 2003. Even before deregulation, there were companies that operated railway
transport on separate lines, not belonging to PKP. These companies, having obtained li-
cences for railway transport, became fully-ﬂedged market players [
]. In subsequent years,
new entrepreneurs appeared, obtained licences and started their transport activities. There
were also companies, controlled by national carriers from other European countries, which
started their business activity in Poland. According to the data of UTK, in 2020, 110 carriers
in Poland were licensed to carry out railway freight transport [
]. The emergence of new
players in the rail freight market results in a loss of market share by the national carrier.
However, intra-modal competition has not protected the freight railway in Poland from
the progressive loss of rail market share in inter-modal competition with road transport.
3.3. Energy Management in DB Cargo Polska
DB Cargo Polska has been present on the Polish market under the DB brand for more
than ten years and is one of the leading players in the rail freight market, but its roots go
back to the 1950s. It was then that the mining industry in Upper Silesia decided to set
up companies specializing in the rail transport of coal between mines, power plants and
coking plants located in the Upper Silesian industrial region, as well as in the haulage
of sand, which at that time was used to ﬁll up depleted mine excavations. A separate
railway infrastructure network, belonging to the mining industry at that time, covering
the entire area of the Upper Silesian industrial region, was used for these transports.
Energies 2021,14, 6875 12 of 21
After the market liberalization in Poland in the 1990s, these companies were privatized
through employee share ownership or investment funds. The development impulse for
these companies was the deregulation of the railway market in Poland, which enabled
them to obtain rail transport licences and freely develop their business using the national
infrastructure, opened by the deregulation of the market also for alternative operators.
These companies have grown organically and through acquisitions, expanding nationwide
and building capital groups. Over time, these companies have also developed their
management systems, using the experience and drawing on models from the industry of
developed Western European economies [
]. Building increasingly complex corporate
structures, these companies also took steps to establish corporate governance tailored to
the scale of their operations [
]. At the beginning of the 21st century, attempts were made
to consolidate these companies—initially internally and later with the help of external
investors. Finally, at the end of 2009, they were purchased by Deutsche Bahn. At that
time, a group of 31 companies was bought and consolidated through a series of mergers.
Currently, DB Cargo Polska is part of the DB Cargo Group, which is a segment of Deutsche
Bahn responsible for the development of the rail freight business in Europe.
After the political reform and market liberalization in Poland in the 1990s, interest in
the concept of sustainable development and related corporate social responsibility emerged
among Polish enterprises [
]. DB Cargo Polska is a company which declares its orientation
towards sustainable development. Therefore, the optimization of energy consumption
ﬁts well with the company’s strategy to ensure the achievement of both economic and
environmental objectives. The area of the railway company’s activity in which energy
consumption is the highest is, of course, transport operation. The company uses both
electric and diesel locomotives for this purpose for transport on non-electriﬁed railway
lines. Diesel shunting locomotives are used for ﬁrst-mile and last-mile operations associated
with sidings and terminals. Another area where the company consumes a relatively large
amount of energy is rolling stock maintenance. For this purpose, the company uses repair
facilities, which consume thermal and electrical energy. The remaining marginal part of
energy consumed by the company is related to its administrative activities.
Electricity used to power the locomotives is purchased from the network manager,
which in Poland is PKP Energetyka. This energy is a variable cost to the company, so its
consumption is proportional to the transport performance of the company. Due to the
problems with the direct accounting of electric energy consumed in the railway network
(described in previous chapters), the statistical method is used for settlements with PKP
Energetyka, which is based on the calculation of the company’s share in the total transport
performance of all carriers using the network in the settlement period. This method cannot
be completely avoided until all vehicles running on the network and using electricity are
equipped with on-board energy consumption meters approved by the power grid manager.
Statistical billing of electricity consumption, when operating, makes it impossible to calcu-
late the energy efﬁciency of a particular operator or a particular locomotive, since operators
are charged for electricity consumption derived from the average energy efﬁciency of
all operators that have used the network. The efﬁciency of the network itself (expressed
in the ratio of energy consumed by operators to energy purchased by the network man-
age) is also of relevance here. Finally, the grid itself generates energy losses connected
with its transmission as well as with the maintenance of transformer stations and other
Taking into account this limitation with regard to the accuracy of accounting for
traction energy consumption, DB Cargo Polska focuses on managing the overall energy ef-
ﬁciency of the company, understood as the relationship between the transport performance
and energy consumed by the company. Although transport performance is equivalent
to the company’s main product, the energy consumed by the company is also used for
additional services offered to customers as part of logistics or railway technology packages,
such as loading or unloading goods, servicing customer rolling stock or servicing the
railway infrastructure at a customer’s siding. Thus, the energy included in the company’s
Energies 2021,14, 6875 13 of 21
statistics contributes to the generation of additional output, which makes the actual energy
efﬁciency of the company higher than the results from the calculation based only on the
Therefore, the total energy consumption of the company consists of: (1) electric
energy consumed by locomotives while operating transport, which is charged by the
network manager based on the statistical method; (2) energy produced by generators of
diesel locomotives used by the company to operate transport and shunting at customer’s
sidings and terminals; (3) energy produced by fuel engines of other vehicles used by the
company; (4) electricity used to power machines in rolling stock repair plants and to light
the company’s property; (5) heat energy used to heat the company’s property. The graph
below shows the shares of the mentioned energy consumption components in total energy
consumption of the company in 2020.
As can be seen from the diagram in Figure 9, the largest share of energy consumption
in the company is that produced by diesel locomotive generators, and the total share of
energy consumed by electric and diesel locomotives reaches 87%. The larger share of energy
consumed by diesel locomotives than the electric locomotives (despite the electriﬁcation
of railways lines in Poland amounting to 61%) is explained by the inclusion of the work
of diesel shunting locomotives, used to perform the ﬁrst and last mile transports as well
as shunting at sidings and customer terminals, where the amount of performed tonne-
kilometers is small in relation to the working time of the locomotive engine used to perform
them. The company has achieved a positive trend in the dynamics of performed tonne-
kilometers between 2012 and 2020. The graph below shows the dynamics of the transport
work in comparison with the dynamics of the total energy consumption in these years.
These two parameters allow to calculate the dynamics of the company’s energy efﬁciency.
Figure 9. Structure of energy use in DB Cargo Polska in 2020. Own study based on company data.
The break in the positive trend in 2020, shown in Figure 10, is due to the economic
collapse caused by the COVID-19 pandemic. The company improved its energy efﬁciency,
measured as the ratio of transport work to the total energy consumption of the company,
by more than 20% between 2012 and 2020. The additional output produced by using this
energy is not easy to operationalize, due to the variety of ancillary services sold. However,
it has been assumed that the measure of this output will be the value of revenues generated
by the company from services that do not constitute rail transport. The graph below shows
the dynamics of the company’s revenue from services that do not generate freight work.
Energies 2021,14, 6875 14 of 21
Transport performance, energy consumption and energy efﬁciency of DB Cargo Polska,
normalized to 2012. Own study based on company data.
As we can see in Figure 11, revenues from ancillary services had positive dynamics
from 2012 to 2020, which means that the actual dynamics of the company’s energy efﬁciency
were higher than presented in Figure 10. In order to increase energy efﬁciency, the company
undertook a number of optimization and innovation projects in all areas of its activity.
The key area in which to look for potential savings in energy consumption is, of course,
the locomotive ﬂeet. The company has been investing in this area since the start of its
activities within the Deutsche Bahn Group. The ﬂeet of locomotives at the company’s
disposal after the takeover by DB consisted of electric locomotives whose average age
in 2010 was 45 years. These locomotives were gradually being phased out of service
and replaced with new electric locomotives which had the ability to regenerate electricity.
After ten years of operation, the average age of the electric locomotives used by DB Cargo
Poland in 2020 has decreased by 20 years. Taking the passage of time into account, this
gives an effective improvement in the age of the ﬂeet of 30 years. The diesel locomotives
owned by the company in 2010 were gradually being replaced by newer-generation diesel
locomotives, which were available for transfer to Poland from the resources of the DB
Cargo Group in Europe. After ten years of functioning of the company, the average age of
diesel locomotives has increased by only 2 years, which gives an effective improvement
of 8 years. This information illustrates the scale of the modernization of the company’s
locomotive ﬂeet. While the improvement in the quality of the company’s ﬂeet of diesel
locomotives is reﬂected in the dynamics of the company’s overall energy efﬁciency shown in
the improvement in the quality of the electric locomotive ﬂeet is not, because the
statistical method of accounting for energy consumption with the network manager makes
it impossible to reﬂect the actual energy consumption of a particular operator.
Energies 2021,14, 6875 15 of 21
Revenue from non-transport services of DB Cargo Polska, normalized to 2012. Own study
based on company data.
The environmental impact of electric locomotives used by the company is determined
not only by their energy efﬁciency, but also by the energy sources used by the network
manager. DB Cargo Poland therefore has no direct inﬂuence on what sources of energy
are used by electric locomotives belonging to the company. Looking for ways to reduce
the carbon intensity of its operations, in 2020, the company signed a letter of intent with
PKP Energetyka, which aims to enable the purchase of energy from renewable sources and
settlement of this purchase between PKP Energetyka and DB Cargo Poland. It should also
be mentioned here that the gradual modernization of the ﬂeet resulted in a reduction of the
time spent on preventive and emergency maintenance of locomotives, thus reducing the
production reserve and improving the productivity of the ﬂeet. In addition, the company
worked on the operational productivity of its ﬂeet by reducing the waiting periods of
locomotives between successive train services. These actions—in addition to improving
ﬁnancial efﬁciency—were also aimed at reducing unproductive energy consumption by
locomotives during waiting times. This is particularly important in the case of diesel
locomotives, which need to maintain proper engine temperature during periods of negative
temperatures, which result in fuel consumption. Figure 12 below shows the dynamics
expressed in tonne-kilometers per locomotive of the productivity of DB Cargo Poland’s
ﬂeet of line locomotives used in 2012–2020.
Rolling stock maintenance is also an important operational area in terms of energy
consumption. The savings in thermal and electrical energy achieved by DB Cargo Polska
in this area result mainly from the restructuring it has undertaken and the process innova-
tions implemented as part of that restructuring. In 2012, the company had maintenance
workshops with a total roofed area of more than 101,000 m
. Work in these workshops was
organized mainly in the nest system, which resulted in the fact that the rolling stock stayed
for a long time in the plant, which resulted in a high demand for the space, on which repair
operations are performed. As the number of locomotives and wagons of older types was
reduced and their productivity improved, some plants were closed and properties were
sold. In 2013, a new wagon inspection repair system, organized in the pipeline system, was
implemented. This organization—based on lean manufacturing methodology, commonly
used in the automotive industry—had not been used in the rolling stock service before.
The introduction of this innovation has signiﬁcantly shortened the time spent in the repair
shop and further reduced the amount of space used by the company for rolling stock
maintenance. By 2020, the company was using a total of less than 47,000 m
space to service its own rolling stock, while at the same time selling some of its production
Energies 2021,14, 6875 16 of 21
capacity to customers outside the company. Thus, the company reduced the size of its
repair facilities by 53% between 2012 and 2020.
In terms of administrative activities, the actions aimed at improving energy efﬁciency
came down to reduction of the used ofﬁce space, thermomodernization of owned properties
and modernization of lighting.
Figure 12. Locomotive productivity of DB Cargo Polska in tkm per locomotive, normalized to 2012.
Own study based on company data.
4. Discussion and Conclusions
The energy efﬁciency of railways is globally much higher than that of its main com-
petitor, road transport. Despite the advantage in energy efﬁciency, as well as the European
Union’s policy declarations regarding the planned increase in the importance of railways,
in recent decades, railways have been losing market share in land transport to road trans-
port. Given the much lower energy efﬁciency of road transport, this has resulted in a
deterioration of the energy efﬁciency of the European transport system.
The European railway system is characterized by considerable complexity in compar-
ison to other railway systems in the world, i.a., due to different energy supply systems
of the network and national borders separating areas served by national railway network
managers. The opening of the railway market in Europe has increased this complexity
by introducing intra-modal competition. This results in a multitude of operators using
individual national networks and operating across national network boundaries. The lo-
comotive ﬂeet in Europe is not completely equipped with on-board energy consumption
meters. As a consequence, network managers and operators need to deal with a lack of
transparency in settlements. Hence, we can conclude that numerous limitations exist for
optimization activities in the ﬁeld of railway energy efﬁciency.
Railways in Poland still have a relatively large share in freight transport, which is
largely due to the high importance of coal in the country’s energy mix. Deregulation of the
railways in Poland has resulted in the emergence of a relatively large number of players in
the rail freight market.
DB Cargo Poland has been operating under the DB brand since 2010, but its legal
predecessors were providing rail freight services before the market liberalization in Poland.
Due to the lack of transparency in the energy efﬁciency of electric locomotives, the company
manages its energy efﬁciency mainly by using a global indicator of energy consumption
per unit of transport performance. Actions to improve the company’s energy efﬁciency
consisted mainly of improving the operational productivity of the locomotive ﬂeet, mod-
ernizing this ﬂeet, and optimizing the ﬂeet maintenance process. Due to the problems with
transparency in accounting for energy consumed by electric locomotives, not all of the
Energies 2021,14, 6875 17 of 21
action taken could be reﬂected in the positive trend in energy efﬁciency recorded by the
company between 2012 and 2020.
Based on the literature review presented, the analysis performed, the business case
considered and the discussion above, the following conclusions can be drawn. The model
of rail transport market regulation introduced in the European Union has had a signiﬁcant
impact on the energy efﬁciency of railways. This model has led to an increase in the
complexity of the billing system for electricity consumption. Limited transparency in
this respect leads to the use of the indirect energy efﬁciency management methods of
railway companies presented on the example of DB Cargo Polska, which makes it difﬁcult
to assess the effectiveness of individual activities aimed at improving energy efﬁciency
as well as reducing the negative environmental impact by railway companies. The far-
reaching liberalization of the rail market in Europe, the purpose of which was to use market
mechanisms to improve the economic efﬁciency of European railways, has so far failed to
break the advantage of road transport, which still takes over most of the transport work
generated by economic growth on the European continent. This liberalization has led
to fragmentation of the railway system and economic optimization on the microscale of
individual enterprises. Due to the commercialization of the management of the power
network, presented on the example of the sale of PKP Energetyka, the company, acting
for its statutory goals, does not have to take into account the economic effects as well as
environmental effects that can be achieved, for example, by reducing energy consumption
for the beneﬁt of grid maintenance, signiﬁcant from the entire railway system. The example
of DB Cargo Polska also shows that despite the existing limitations, railway companies
undertake various activities aimed at improving their energy efﬁciency and are in a position
to demonstrate the combined effectiveness of their activities. Obtaining transparency in the
scope of the effects of individual activities without breaking the existing interoperability
barriers and unifying the billing system for electricity consumption in Europe seems to be
impossible, and the possibility of reducing electricity consumption in the railway system
by implementing optimization of timetables, as is the case in systems underground, seems
to be still unreachable.
Given the limited access to energy efﬁciency data for speciﬁc vehicles and individual
segments of the power grid, it would be advisable to undertake research by market
regulators who could access this type of data. It would also be interesting to study
the effectiveness of the electriﬁcation of the railway network or the uniﬁcation of the
parameters of the current used in the European railway network, from the perspective of
railway energy efﬁciency.
Conceptualization, A.K. and M.S.; methodology, A.K. and M.S.; validation,
A.K. and M.S.; investigation, A.K. and M.S.; resources, A.K. and M.S.; writing—original draft
preparation, A.K. and M.S.; writing—review and editing, A.K. and M.S.; visualization, A.K. and
M.S.; funding acquisition, A.K. All authors have read and agreed to the published version of
This research was funded by Department of Applied Social Sciences of the Faculty
of Organization and Management of the Silesian University of Technology, grant number 2021:
Data Availability Statement:
The following public data sources were used in the research. Available
online: https://uic.org/IMG/pdf/handbook_iea-uic_2017_web3.pdf (accessed on 14 April 2021).
Available online: http://en.worldstat.info/World/List_of_countries_by_Density_of_railways (ac-
cessed on 14 April 2021). Available online: https://ec.europa.eu/eurostat/databrowser/view/t202
0_rk310/default/table?lang=en (accessed on 14 April 2021). Data on the activities of the company
that is the subject of the case study were made available based on the data disclosure agreement.
Conﬂicts of Interest: The authors declare no conﬂict of interest.
Energies 2021,14, 6875 18 of 21
Directive 2006/32/EC of the European Parliament and of the Council of 5 April 2006 on Energy End-Use Efﬁciency and Energy
Services and Repealing Council Directive 93/76/EEC. Available online: https://eur-lex.europa.eu/legal-content/pl/TXT/?uri=
CELEX%3A32006L0032 (accessed on 14 April 2021).
United Nations. Agenda 21: Earth Summit: The United Nations Programme of Action from Rio. 1993. Available online:
https://sustainabledevelopment.un.org/outcomedocuments/agenda21 (accessed on 14 April 2021).
von Weizsäcker, E.U.; Lovins, A.B.; Lovins, L.H. Mno ˙
znik Cztery: Podwojony Dobrobyt-Dwukrotnie Mniejsze Zu˙
Naturalnych; Polskie Towarzystwo Współpracy z Klubem Rzymskim: Rome, Italiy, 1999.
4. Kuzior, A. Aksjologia Zrównowa˙
zonego Rozwoju; Belianum: Banská Bystrica, Slovakia, 2014.
von Weizsacker, E.U.; Hargroves, C.; Smith, M.H.; Desha, C.; Stasinopoulos, P. Factor Five, 1st ed.; Routledge: London, UK, 2009.
UNEP. The Business Case for the Green Economy: Sustainable Return on Investment. 2012. Available online: http://www.unep.
org/greeneconomy/Portals/88/documents/partnerships/UNEP%20BCGE%20A4.pdf (accessed on 14 April 2021).
Kuzior, A. Polskie i niemieckie do´swiadczenia w projektowaniu i wdra˙
zonego rozwoju [Polish and German
Experiences in Planning and Implementation of Sustainable Development]. Probl. Ekorozwoju-Probl. Sustain. Dev.
Lyulyov, O.; Pimonenko, T.; Kwilinski, A.; Dzwigol, H.; Dzwigol-Barosz, M.; Pavlyk, V.; Barosz, P. The Impact of the Government
Policy on the Energy Efﬁcient Gap: The Evidence from Ukraine. Energies 2021,14, 373. [CrossRef]
Bartnikowska, S.; Olszewska, A.; Czekała, W. Stan obecny przył ˛acze ´n instalacji OZE do systemu elektroenergetycznego [The
current state of connection issues of renewable energy sources installations to the electrical grid]. Polityka Energetyczna Energy
Policy J. 2017,20, 117–128.
Van Meerbeek, K.; Ottoy, S.; De Meyer, A.; Van Schaeybroeck, T.; Van Orshoven, J.; Muys, B.; Hermy, M. The bioenergy potential
of conservation areas and roadsides for biogas in an urbanized region. Appl. Energy 2015,154, 742–751. [CrossRef]
Cho, Y.S.; Choi, Y.H. Methodology for Implementing the State Estimation in Renewable Energy Management Systems. Energies
2021,14, 2301. [CrossRef]
Xiong, S.; Hou, Z.; Zou, S.; Lu, X.; Yang, J.; Hao, T.; Zhou, Z.; Xu, J.; Zeng, Y.; Xiao, W.; et al. Direct Observation on p- to
n-Type Transformation of Perovskite Surface Region during Defect Passivation Driving High Photovoltaic Efﬁciency. Joule
5, 467–480. [CrossRef]
Jiménez-Castillo, G.; Rus-Casas, C.; Tina, G.; Muñoz-Rodriguez, F. Effects of smart meter time resolution when analyzing
photovoltaic self-consumption system on a daily and annual basis. Renew. Energy 2021,164, 889–896. [CrossRef]
Mayer, F.D.; Brondani, M.; Carrillo, M.C.V.; Hoffmann, R.; Lora, E.E.S. Revisiting energy efﬁciency, renewability, and sustainability
indicators in biofuels life cycle: Analysis and standardization proposal. J. Clean. Prod. 2020,252, 119850. [CrossRef]
Rodias, E.; Berruto, R.; Bochtis, D.; Busato, P.; Sopegno, A. A Computational Tool for Comparative Energy Cost Analysis of
Multiple-Crop Production Systems. Energies 2017,10, 831. [CrossRef]
Szl˛ek, A.; Werle, S.; Schaffel, N.; Wilk, R. Czyste technologie pozyskiwania energii z w ˛egla oraz perspektywy bezpłomieniowego
spalania [Clean coal energy technologies and perspective of ﬂameless coal combustion]. Rynek Energii 2009,83, 39–45.
Balku, ¸S. Analysis of combined cycle efﬁciency by simulation and optimization. Energy Convers. Manag.
Tic, W.; Junga, R. Wpływ katalizatorów metalicznych na efektywno´s´c energetyczn ˛a i ekologiczn ˛a spalania ci˛e ˙
opałowych [The impact of metallic catalysts of heavy fuels oil combustion on the energetic and ecological efﬁciency]. Przemysł
Chem. 2017,1, 122–124. [CrossRef]
Wang, T.; Xu, L.; Chen, Z.; Guo, L.; Zhang, Y.; Li, R.; Peng, T. Central site regulation of cobalt porphyrin conjugated polymer to
give highly active and selective CO2reduction to CO in aqueous solution. Appl. Catal. B Environ. 2021,291, 120128. [CrossRef]
Mi´skiewicz, R. Efﬁciency of Electricity Production Technology from Post-Process Gas Heat: Ecological, Economic and Social
Beneﬁts. Energies 2020,13, 6106. [CrossRef]
Radulescu, B.A.; Radulescu, V. Numerical Modeling of Intelligent Heating Systems to Improve their Energetic Efﬁciency. In
Proceedings of the 2019 International Conference on Electromechanical and Energy Systems (SIELMEN), Craiova, Romania, 9–11
October 2019; IEEE: Craiova, Romania, 2019; pp. 1–7. [CrossRef]
Luna, T.; Ribau, J.; Figueiredo, D.; Alves, R. Improving energy efﬁciency in water supply systems with pump scheduling
optimization. J. Clean. Prod. 2019,213, 342–356. [CrossRef]
Meng, F.; Xu, B.; Zhang, T.; Muthu, B.; Sivaparthipan, C.B. Application of AI in image recognition technology for power line
inspection. Energy Syst. 2021. [CrossRef]
Agostinelli, S.; Cumo, F.; Guidi, G.; Tomazzoli, C. Cyber-Physical Systems Improving Building Energy Management: Digital
Twin and Artiﬁcial Intelligence. Energies 2021,14, 2338. [CrossRef]
Chen, Y.Y.; Chen, M.H.; Chang, C.M.; Chang, F.S.; Lin, Y.H. A Smart Home Energy Management System Using Two-Stage
Non-Intrusive Appliance Load Monitoring over Fog-Cloud Analytics Based on Tridium’s Niagara Framework for Residential
Demand-Side Management. Sensors 2021,21, 2883. [CrossRef] [PubMed]
Zhang, M.; Zhang, Q.; Lv, Y.; Sun, W.; Wang, H. An AI based High-speed Railway Automatic Train Operation System Analysis
and Design. In Proceedings of the 2018 International Conference on Intelligent Rail Transportation (ICIRT), Singapore, 12–14
December 2018; pp. 1–5. [CrossRef]
Energies 2021,14, 6875 19 of 21
Lopez-Ibarra, J.A.; Goitia-Zabaleta, N.; Camblong, H.; Milo, A.; Gaztanaga, H. Intelligent and Adaptive Fleet Energy Management
Strategy for Hybrid Electric Buses. In Proceedings of the 2019 IEEE Vehicle Power and Propulsion Conference (VPPC), Hanoi,
Vietnam, 14–17 October 2019; IEEE: Hanoi, Vietnam, 2019; pp. 1–6. [CrossRef]
Hell, C.R.; Ilie, C. Study on the further development of energy efﬁciency networks in the context of sustainable management of
organizations. Qual.-Access Success 2019,15, 21–36.
Salem, I.B.; Taghouti, L.; Ouni, L.E.A. Development and test of an energetic management package for industrial process efﬁciency.
Electron. Gov. Int. J. 2019,15, 21. [CrossRef]
Gandenberger, T.; Frauendorf, J.; Wellbrock, W. Lean und Green—Energieefﬁzienz in der industriellen Produktion [Lean and
green-Energy efﬁciency in industrial production]. ZWF Zeitschrift für Wirtschaftlichen Fabrikbetrieb
,112, 417–420. [CrossRef]
Kharazishvili, Y.; Kwilinski, A.; Sukhodolia, O.; D´zwigoł, H.; Bobro, D.; Kotowicz, J. The Systemic Approach for Estimating and
Strategizing Energy Security: The Case of Ukraine. Energies 2021,14, 2126. [CrossRef]
Kuzior, A.; Kwilinski, A.; Hroznyi, I. The Factorial-Reﬂexive Approach to Diagnosing the Executors’ and Contractors’ Attitude to
Achieving the Objectives by Energy Supplying Companies. Energies 2021,14, 2572. [CrossRef]
Yang, Q.; Hu, X.; Wang, Y.; Liu, Y.; Liu, J.; Ma, J.; Wang, X.; Wan, Y.; Hu, J.; Zhang, Z.; et al. Comparison of the impact of China’s
railway investment and road investment on the economy and air pollution emissions. J. Clean. Prod.
,293, 126100. [CrossRef]
Murta, A.L.S.; Freitas, M.A.V.D.; Ferreira, C.G.; Peixoto, M.M.D.C.L The use of palm oil biodiesel blends in locomotives: An
economic, social and environmental analysis. Renew. Energy 2021,164, 521–530. [CrossRef]
Feng, M.; Wu, C.; Lu, S. A New Operation-Oriented Mixed Integer Linear Programming Model for Energy-Efﬁcient Train
Operations. In Proceedings of the 10th International Conference on Power and Energy Systems (ICPES), Chengdu, China, 25–27
December 2020; IEEE: Chengdu, China, 2020; pp. 350–355. [CrossRef]
Vasilenko, M.; Kuzina, E.; Bespalov, V.; Drozdov, N.; Tagiltseva, J.; Korenyakina, N.; Prokopchuk, V.; Nadolinsky, P. Digital
technologies in quality and efﬁciency management of transport service. E3S Web Conf. 2021,244, 11046. [CrossRef]
Jabło´nski, A.; Jabło ´nski, M. Social Perspectives in Digital Business Models of Railway Enterprises. Energies
Sirina, N.; Yushkova, S. Polygon Principles for Integrative Digital Rail Infrastructure Management. Transp. Res. Procedia
54, 208–219. [CrossRef]
Olentsevich, A.A.; Konyukhov, V.Y.; Guseva, E.A.; Konstantinova, M.V.; Olentsevich, V.A. Automation of the splitting-up
processes of freight trains on the gravity sorting yards in the railway transport system. IOP Conf. Ser. Mater. Sci. Eng.
1064, 012029. [CrossRef]
Staszek, M.; Mikulski, J. Zastosowanie symulacyjnych programów komputerowych do przeprowadzania dowodów bezpieczno´sci
urz ˛adze´n elektronicznych na przykładzie analogowego komparatora [An application of simulation software to conducting safety
proofs of electronic devices on the example of an analog comparator]. In Komputerowe Systemy Wspomagania Prac In˙
Kosma, Z., Ed.; Wy˙
zsza Szkoła In˙
zynierska w Radomiu: Radom, Poland, 1994.
Kuzior, A.; Kwilinski, A.; Tkachenko, V. Sustainable development of organizations based on the combinatorial model of artiﬁcial
intelligence. Entrep. Sustain. Issues 2019,7, 1353–1376. [CrossRef]
Tkachenko, V.; Kuzior, A.; Kwilinski, A. Introduction of artiﬁcial intelligence tools into the training methods of entrepreneurship
activities. J. Entrep. Educ. 2019,22, 10.
Kwilinski, A.; Kuzior, A. Cognitive Technologies in the Management and Formation of Directions of the Priority Development of
Industrial Enterprises. Manag. Syst. Prod. Eng. 2020,28, 133–138. [CrossRef]
Riego-Martinez, J.; Perez-Alonso, M.; Duque-Perez, O. Inﬂuence of the rail electriﬁcation system topology on the energy
consumption of train trajectories. IET Renew. Power Gener. 2020,14, 3589–3598. [CrossRef]
Barinov, I.A.; Melnichenko, O.V. Power IGBTs Application in AC-Wire DC-Motor Locomotive Thyristor-Based Power Circuit for
Regenerative Brake Energy Efﬁciency Increase. In Proceedings of the 2019 International Conference on Industrial Engineering,
Applications and Manufacturing (ICIEAM), Sochi, Russian, 25–29 March 2019; IEEE: Sochi, Russia, 2019; pp. 1–5. [CrossRef]
Furutani, R.; Kudo, F.; Moriwaki, N. Case study on detecting feature value for energy efﬁciency in railway operations. Jpn. Railw.
Eng. 2017,2017, 16–18.
International Union of Railways. Railway Handbook 2017. Available online: https://uic.org/IMG/pdf/handbook_iea-uic_2017
_web3.pdf (accessed on 14 April 2021).
Wójcik, P. Znaczenie studium przypadku jako metody badawczej w naukach o zarz ˛adzaniu [The importance of the case study as
a research method in management science]. E-Mentor 2013,1, 17–22.
49. Rossberg, R.R., Ed. Geschichte der Eisenbahn [The History of Railways]; Faunus Verlag: Basel, Switzerland, 1977; pp. 5–32.
WorldStat. List of countries of the World—Density of railways. Available online: http://en.worldstat.info/World/List_of_
countries_by_Density_of_railways (accessed on 14 April 2021).
Mortimer, P.; Islam, D.M.Z. A comparison of North American and European railway systems—A critique and riposte. Eur.
Transp. Res. Rev. 2014,6, 503–510. [CrossRef]
Kramarz, M.; Dohn, K.; Przybylska, E.; Knop, L. Scenarios for the Development of Multimodal Transport in the TRITIA
Cross-Border Area. Sustainability 2020,12, 7021. [CrossRef]
53. Frey, S. Railway Electriﬁcation Systems & Engineering; World Technologies: Delhi, India, 2014.
Energies 2021,14, 6875 20 of 21
European Commission. Roadmap to a Single European Transport Area— Towards a Competitive and Resource Efﬁcient Transport
System. White Paper. 2011. Available online: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=COM:2011:0144:FIN:
EN:PDF (accessed on 14 April 2021).
European Commission. Electriﬁcation of the Transport System; Studies and Reports; Technical Report; European Commission:
Brussels, Belgium, 2017.
Popescu, M.; Bitoleanu, A. A Review of the Energy Efﬁciency Improvement in DC Railway Systems. Energies
International Union of Railways. Technologies and Potential Developments for Energy Efﬁciency and CO
Reductions in Rail Systems;
Technical Report; International Union of Railways: Paris, France, 2016.
Gunselmann, W. Technologies for increased energy efﬁciency in railway systems. In Proceedings of the 2005 European Conference
on Power Electronics and Applications, Toulouse, France, 11–14 September 2005; IEEE: Dresden, Germany, 2005; p. 10. [CrossRef]
Tolliver, D.; Lu, P.; Benson, D. Analysis of Railroad Energy Efﬁciency in the United States; North Dakota State University, Upper
Great Plains Transportation Institute, Mountain-Plains Consortium: Fargo, North Dakota, 2013. Available online: https:
//www.ugpti.org/resources/reports/downloads/mpc13-250.pdf (accessed on 1 July 2021).
Lipscy, P.Y.; Schipper, L. Energy efﬁciency in the Japanese transport sector. Energy Policy
Hayashiya, H. Recent Trend of Regenerative Energy Utilization in Traction Power Supply System in Japan. Urban Rail Transit
2017,3, 183–191. [CrossRef]
Bärmann, A.; Martin, A.; Schneider, O. Efﬁcient Formulations and Decomposition Approaches for Power Peak Reduction in
Railway Trafﬁc via Timetabling. Transp. Sci. 2021,55, 747–767. [CrossRef]
European Transport Policy for 2010: Time to Decide. White Paper. Available online: https://ec.europa.eu/transport/sites/
transport/ﬁles/themes/strategies/doc/2001_white_paper/lb_com_2001_0370_en.pdf (accessed on 14 April 2021).
Crozet, Y. Rail freight development in Europe: How to deal with a doubly-imperfect competition? Transp. Res. Procedia
25, 425–442. [CrossRef]
65. Katz, M.L.; Shapiro, C. Network Externalities, Competition, and Compatibility. Am. Econ. Rev. 1985,75, 424–440.
Council of the European Communities. Council Directive on the Development of the Community’s Railways. 1991. Available
online: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:31991L0440&from=EN (accessed on 14 April 2021).
Directive 98/5/EC of the European Parliament and of the Council of 16 February 1998 on the allocation of railway infrastructure
capacity and the levying of charges for the use of railway infrastructure and safety certiﬁcation. In Core EU Legislation; Bloomsbury
Publishing: London, UK, 1998._22. [CrossRef]
Friebel, G.; Ivaldi, M.; Vibes, C. Railway (De)Regulation: A European Efﬁciency Comparison. Economica
Ait Ali, A.; Eliasson, J. European railway deregulation: An overview of market organization and capacity allocation. Transp. A
Transp. Sci. 2021, 1–25. [CrossRef]
Posner, H. Rail Freight in the USA: Lessons for Continental Europe; Technical Report; Community of European Railway and
Infrastructure Companies: Brussels, Belgium, 2008.
European Rail Infrastructure Managers. EIM Position Paper on Energy Meters on Electric Trains. Available online: https:
//eress.eu/media/38232/eim-position-paper-on-energy-metering-on-electric-trains.pdf (accessed on 14 April 2021).
European Rail Infrastructure Managers. EIM Position Paper on Cross Acceptance of On-Board Energy Measuring Systems. Avail-
able online: https://eress.eu/media/1064/eim-cross-acceptance-of-energy-measuring-systems.pdf (accessed on 14 April 2021).
Gatti, A.; Ghelardini, A. The European Energy Measurement System on board trains. In Proceedings of the 9th World Congress
on Railway Research, Challenge A: A More and More Energy Efﬁcient Railway Session A4—Energy Efﬁciency, Lille, France,
22–26 May 2011.
Urz ˛ad Transportu Kolejowego [Polish Ofﬁce of Rail Transport]. Podsumowanie 2020. Przewozy Pasa ˙
zerskie i Towarowe
[Summary of 2020. Passenger and Freight Transportation]. Available online: https://utk.gov.pl/pl/dokumenty-i-formularze/
opracowania-urzedu-tran/16653,Podsumowanie- 2020-przewozy-pasazerskie-i-towarowe.html (accessed on 14 April 2021).
Eurostat. Modal Split of Passenger Transport. Available online: https://ec.europa.eu/eurostat/databrowser/view/t2020_rk310
/default/table?lang=en (accessed on 14 April 2021).
Eurostat. Modal Split of Freight Transport. Available online: https://ec.europa.eu/eurostat/databrowser/view/t2020_rk320
/default/table?lang=en (accessed on 14 April 2021).
Fitzová, H. European railway reforms and efﬁciency: Review of evidence in the literature. Rev. Econ. Perspect.
European Commission. Answer Given by Ms Vestager on Behalf of the Commission; European Commission: Brussels, Belgium,
2015. Available online: https://www.europarl.europa.eu/doceo/document/P-8-2015-012731- ASW_PL.pdf (accessed on 14
Staszek, M. Relacje z interesariuszami w ramach modelu odpowiedzialno´sci społecznej przedsi ˛ebiorstwa na przykładzie DB
Cargo Polska [Relations with stakeholders within the corporate social responsibility model based on the example of DB Cargo
Polska]. Etyka Biznesu ZróWnowa˙
zOny Rozw. Interdyscyplinarne Stud. Teoretyczno-Empiryczne 2020,3, 7–21.
Energies 2021,14, 6875 21 of 21
Kolejowi Przewo´znicy Towarowi w Polsce. Badanie Przewo´zników, Którzy Licencje Uzyskali w Latach 2013–2020 [Rail Freight Carriers
in Poland A Survey of Carriers That Were Licensed between 2013 and 2020]; [Polish Ofﬁce of Rail Transport]; Technical Report; Urz ˛ad
Transportu Kolejowego: Warszawa, Poland, 2021.
Jabło´nski, A.; Jabło ´nski, M.; Staszek, M. Studium przypadku: Integracja systemu controllingu z systemem zarz ˛adzania jako´sci ˛a
na przykładzie przedsi˛ebiorstwa usługowego [Case study: Integration of controlling system with quality management system on
the example of a service company]. Control. Rachun. Zarz ˛aDcza 2005,9, 12–17.
Jabło´nski, A.; Jabło ´nski, M.; Staszek, M. Studium przypadku: Organizacja systemu informacyjnego controllingu w grupie
kapitałowej [Case study: Organization of controlling information system in a capital group]. Control. Rachun. Zarz ˛adcza