IEC TR 63388:2021

Report on the development of cogeneration

IEC TR 63388:2021 introduces the widely used technical scheme of cogeneration (also known as combined heat and power (CHP)), and gives the corresponding cases. The technical schemes of cogeneration covered in this technical report can be divided into two categories. One is cogeneration based on steam turbine, which is generally applied in thermal power plants; The other is cogeneration based on other prime movers, such as fuel cell, micro gas turbine, internal combustion engine, Stirling engine, ORC, etc.
This document gives some cases of cogeneration, mainly including:
• CHP based on extraction turbine;
• CHP based on back pressure turbine;
• Low-vacuum heating mode;
• LP cylinder steam bypassed heating mode;
• CHP based on steam turbine with synchro-self-shift clutches;
• Gas-steam combined cycle CHP;
• Micro gas turbine CHP;
• Stirling engine CHP;
• Fuel cell CHP; and
• ORC CHP.
The characteristics, components and technical requirements of these technical schemes are introduced in this document.
By collecting existing standards of CHP, this document also identifies the gaps of CHP standardization and put forward a roadmap for future CHP standards.
This document is prepared based on limited expert resources. Thus, some cogeneration cases could not be covered in this document, such as:
• Solar cogeneration; and
• Internal combustion engine cogeneration.

General Information

• Status: Published
• Publication Date: 06-Dec-2021
• ICS: 27.040 - Gas and steam turbines. Steam engines
• Technical Committee: TC 5 - Steam turbines
• Current Stage: PPUB - Publication issued
• Start Date: 07-Dec-2021
• Completion Date: 03-Jan-2022

Standards Content (Sample)

IEC TR 63388 ®
Edition 1.0 2021-12
TECHNICAL
REPORT
colour
inside
Report on the development of cogeneration
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IEC TR 63388 ®
Edition 1.0 2021-12
TECHNICAL
REPORT
colour
inside
Report on the development of cogeneration

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.040 ISBN 978-2-8322-1058-7

– 2 – IEC TR 63388:2021 © IEC 2021
CONTENTS
FOREWORD . 4
1 Background . 6
1.1 Task following SMB decision . 6
1.2 Scope . 7
1.3 Purpose . 8
2 Terms, definitions and abbreviated terms . 8
2.1 Terms and definitions . 8
2.2 Abbreviated terms . 10
3 Overview of CHP . 10
3.1 What is CHP? . 10
3.2 Benefits of CHP . 12
3.3 Efficiency of CHP system . 13
4 Market situation of cogeneration . 14
4.1 Global situation . 14
4.2 European situation . 14
4.3 American situation . 15
4.4 Asian situation . 15
4.5 Summary . 17
5 CHP based on steam turbine . 17
5.1 General introduction . 17
5.2 Technical characteristics . 18
5.2.1 CHP based on extraction turbine . 18
5.2.2 CHP based on back pressure turbine . 18
5.2.3 Low-vacuum heating mode . 19
5.2.4 LP cylinder steam bypassed heating mode . 20
5.2.5 CHP based on steam turbine with synchro-self-shift clutch . 21
5.2.6 Special case: gas-steam combined cycle CHP . 22
5.3 Components . 23
5.4 Requirements . 24
5.5 Summary . 26
6 CHP based on other processes . 26
6.1 General . 26
6.2 Technical characteristics . 27
6.2.1 Gas turbine CHP . 27
6.2.2 Stirling engine CHP . 28
6.2.3 Fuel cell CHP . 29
6.2.4 ORC CHP . 30
6.3 Components . 31
6.4 Requirements . 32
6.5 Summary . 33
7 Standardization demand of CHP . 33
7.1 Necessity to develop CHP technical standards. 33
7.2 Current status of ISO/IEC standards related to CHP . 34
7.2.1 General . 34
7.2.2 CHP system level . 35
7.2.3 CHP communication level . 35

7.2.4 CHP component level . 35
7.3 Summary . 40
8 CHP standardization roadmap . 40
8.1 Envisaged CHP standard architecture . 40
8.2 Description of the standard architecture . 41
8.3 Developing the path of future standards . 42
8.3.1 Develop path– Start from system to component level . 42
8.3.2 Work of joint working group . 43
8.4 Developing committee recommendations . 43
8.5 Summary . 43

Figure 1 –CHP based on steam turbine . 11
Figure 2 – CHP based on combustion turbine or reciprocating engine . 11
Figure 3 – Example of energy efficiency for different generating systems . 12
Figure 4 – Proportion of different heating modes in urban areas of northern China . 16
Figure 5 – Cogeneration status in Japan by fuel types . 17
Figure 6 – Heating system based on extraction steam turbine . 18
Figure 7 – Back pressure turbine heating system . 19
Figure 8 – Typical diagram of a low-vacuum heating system . 20
Figure 9 –Schematic of LP cylinder steam bypass heating technology . 21
Figure 10 – Heating turbine with synchro-self-shift clutch . 22
Figure 11 – Schematic diagram of combined cycle unit cogeneration . 23
Figure 12 – Typical work flow of CHP system based on steam turbine . 23
Figure 13 – Energy efficiency comparison between small-scale CHP system and
traditional energy services . 27
Figure 14 – CHP system based on micro gas turbine . 28
Figure 15 –CHP system based on STIG . 28
Figure 16 – Typical Stirling engine CHP unit process . 29
Figure 17 – Fuel cell CHP system . 30
Figure 18 – ORC CHP system . 31
Figure 19 – Link between CHP system and user demands . 34

Table 1 – Installed capacity of cogeneration units in Japan as of March 2020 . 16
Table 2 – Status of CHP standards . 36
Table 3 – CHP standard architecture . 41

– 4 – IEC TR 63388:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
REPORT ON THE DEVELOPMENT OF COGENERATION

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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IEC TR 63388 has been prepared by IEC technical committee 5: Steam turbines. It is a
Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
5/243/DTR 5/244/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
available at www.iec.ch/members_experts/refdocs. The main document types developed by
IEC are described in greater detail at www.iec.ch/standardsdev/publications.

The committee has decided that the contents of this document will remain unchanged until the
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specific document. At this date, the document will be
• reconfirmed,
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• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
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– 6 – IEC TR 63388:2021 © IEC 2021
REPORT ON THE DEVELOPMENT OF COGENERATION

1 Background
1.1 Task following SMB decision
Following the Standards Management Board (SMB) decision 141/10, IEC Technical
Committee 5 (Steam Turbine) was tasked to lead a joint working group with related IEC and
ISO committees to explore potential standardization opportunities.
SMB decision 141/10reads as follows:
SMB decision 141/10 – SMB AhG 30: Co-generation – IEC involvement in joint work with
ISO
The SMB, further to having taken decisions confirming IEC's commitment to providing
support to the areas of cogeneration technology within its area of competence in particular
aspects related to electrical power generation, decided to instruct IEC TC 5 to be the
primary point of contact, to follow this activity in coordination with TC 45 and TC 105.
The SMB requests AhG 30 to submit a final report and recommendations on future work
and any future activities by end July 2011, and decided to disband the SMB AhG 30 after
submission of the report.
Based on the AhG recommendations, SMB will then communicate an IEC perspective on
this matter to ISO.
With the above SMB decision, IEC Technical Committee 5 established Joint Working Group
16 (Cogeneration Combined Heat and Power (CHP)) in 2012-09.
After IEC/TC5/JWG16 was established, working steps were proposed (see 5/168/AC) as
follows:
No. Working step Remarks
1 Complete an overview on standards related to CHP Also include standards if they only partly cover
technology. CHP aspects
2 Clarification of status and application experience of Efficiency of CHP solutions is in focus for all
Manual CWA 45547 applications. The Manual CWA 45547 from 2004
could be a basis for an IEC standardization project.
There might be valuable feedback available from
application of the Manual.
3 Screening of world-wide applied alternative
methods for determination of CHP efficiency
4 Clarification of the need for standards dealing with Consider the different needs for the residential,
aspects different to efficiency such as safety, commercial and industrial needs including the
performance and installation. A differentiation different power sizes. EN 50465:2008 GAS
between residential / commercial mass products APPLIANCES – COMBINED HEAT AND POWER
and power plants should be considered. It should APPLIANCE OF NOMINAL HEAT INPUT
be identified where the current standardisation INFERIOR OR EQUAL TO 70 KW? IEC62282 Fuel
activities are going on in ISO or IEC and where the Cell Technologies Germany: FW308 July 2011
need for new coordination between IEC / ISO TCs
Status per 03-2012: The common aspects of safety
is suggested.
related control are already covered by other IEC
and ISO standards on Functional Safety. No
additional aspects for standardization with respect
to CHP identified. The common aspects of
application of gas and oil valves are covered by
other IEC and ISO standards. No additional
aspects for standardization with respect to CHP
identified.
5 Clarification if there is any other product/solution Possible aspects are also grid parallel operation of
specific standardization need in the area of CHP the CHP.
6 Update necessary liaisons with other TCs within IEC TC45 Nuclear instrumentation? IEC TC105
IEC or ISO Fuel cell technologies? ISO TC192 Gas Turbines?
ISO TC208 Thermal turbines for industrial
application (steam turbines, gas expansion
turbines)? Other TCs?
7 Prepare Proposal of standardization Work Item Proposal might include the target to align the
(PWI) for voting in TC5 and relevant other TCs context of the new IEC standard in a way that it
later – as an EN IEC standard – can be
harmonized with the EC Directive 2004/08
(Combined Heat and Power (CHP) Directive).
8 Clarification of which other IEC or ISO standards Chapters on CHP efficiency in other standards for
have to be adapted, when new IEC standard in individual applications should be replaced by a
CHP efficiency becomes valid. Preparation of reference on the new IEC standard.
requests to other TCs for adaptation/update of
In C-type standards describing the efficiency of a
other standards.
certain technology relevant to CHP a reference on
the new IEC standard on CHP efficiency should be
included.
9 Clarification with CEN/CENELEC on withdrawal of
Manual CWA 45547
This technical report is intended to address the above items 1, 3, 4, 5, 7, and 8.
Other items will be addressed depending on the outcome of this report.
1.2 Scope
This document, which is a technical report, introduces the widely used technical scheme of
cogeneration (also known as combined heat and power (CHP)), and gives the corresponding
cases. The technical schemes of cogeneration covered in this technical report can be divided
into two categories. One is cogeneration based on steam turbine，which is generally applied
in thermal power plants; The other is cogeneration based on other prime movers, such as fuel
cell, micro gas turbine, internal combustion engine, Stirling engine, ORC, etc.

– 8 – IEC TR 63388:2021 © IEC 2021
This document gives some cases of cogeneration, mainly including:
• CHP based on extraction turbine;
• CHP based on back pressure turbine;
• Low-vacuum heating mode;
• LP cylinder steam bypassed heating mode;
• CHP based on steam turbine with synchro-self-shift clutches;
• Gas-steam combined cycle CHP;
• Micro gas turbine CHP;
• Stirling engine CHP;
• Fuel cell CHP; and
• ORC CHP.
The characteristics, components and technical requirements of these technical schemes are
introduced in this document.
By collecting existing standards of CHP, this document also identifies the gaps of CHP
standardization and put forward a roadmap for future CHP standards.
This document is prepared based on limited expert resources. Thus, some cogeneration
cases could not be covered in this document, such as:
• Solar cogeneration; and
• Internal combustion engine cogeneration.
1.3 Purpose
Based on the decision of the SMB, the purpose of this document is to briefly introduce the
technical characteristics and requirements of different cogeneration schemes, analyse the
standard status and standard gap, put forward roadmap and suggestions for the development
of cogeneration standards in the future.
2 Terms, definitions and abbreviated terms
2.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
2.1.1
combined heat and power (CHP)
energy efficient technology that generates electricity and captures the heat that would
otherwise be wasted to provide useful thermal energy - such as steam or hot water - that can
be used for space heating, cooling, domestic hot water and industrial processes
[SOURCE: "Combined Heat and Power (CHP) Partnership" from EPA]

2.1.2
cogeneration
simultaneous production in series of two forms of useful energy such as electrical energy first
and then useful thermal energy from a single fuel source
Note 1 to entry: In this document, cogeneration refers to CHP.
2.1.3
primary energy
energy that has not been subjected to any conversion or transformation process
Note 1 to entry: Primary energy includes non-renewable energy and renewable energy. If both are taken into
account it can be called total primary energy.
[SOURCE: ISO 52000-1:2017, 3.4.29]
2.1.4
heating
process of increasing the temperature of medium by the means of the transportation fluid from
the heating plant over a heat exchanger
2.1.5
heating season
part of the year during which heating is needed to keep the indoor temperature within
specified levels, at least part of the day and in part of the rooms
Note 1 to entry: The length of the heating season differs substantially from country to country and from region to
region.
Note 2 to entry: This term is especially for district heating period of a year.
[SOURCE: ISO 17772-1:2017, 3.15]
2.1.6
heating system
system where the working fluid is heated by the transportation fluid coming from the CHP
plant for any purposes, such as process, building heating, hot water, etc.
2.1.7
district heating
heating systems that distribute steam or hot water through pipes to a number of buildings
across a district
Note 1 to entry: Heat is provided from a variety of sources, including geothermal, combined heat and power
plants, waste heat from industry, or purpose-built heating plants.
[SOURCE: ISO 14452:2012, 2.23]
2.1.8
industrial heat supply
heat supply where the working fluid takes part with the industrial process or the heat of the
working fluid is transferred to the industrial process over a heat exchanger
Note 1 to entry: In the former case, no residual heat is returned to the CHP system. In the latter case, the residual
heat may be returned to the CHP system.
2.1.9
extraction turbine
turbine in which some of the steam is extracted part-way through the expansion using
pressure control means for the extracted steam

– 10 – IEC TR 63388:2021 © IEC 2021
Note 1 to entry: The control means are located inside the turbine flow path or in a cross-over line between turbine
sections. The target is to provide process steam.
Note 2 to entry: Control of extraction pressure can be internal, external or combined internal/external. For
externally controlled extractions the control means are located in the extraction steam line. The aim is to control
steam parameters downstream of the control means, i.e. on the process side. In this case the turbine is not called
an extraction turbine.
Note 3 to entry: If no means for controlling the pressure are used, this steam line is called a bleed, and the
turbine is not called an extraction turbine.
[SOURCE: IEC 60045-1:2020 © IEC 2020]
2.1.10
back pressure turbine
turbine whose exhaust heat typically will be used to provide process heat (e.g. industrial
process, district heating, post combustion carbon capture system and desalination), and
whose exhaust is not directly connected to a condenser
Note 1 to entry: The exhaust pressure will normally be above atmospheric pressure.
[SOURCE: IEC 60045-1:2020© IEC 2020]
2.2 Abbreviated terms
CHP combined heat and power
SMB standardization management board
ORC organic Rankine cycle
HP high pressure
IP intermediate pressure
LP low pressure
HRSG heat recovery steam generator
3 Overview of CHP
3.1 What is CHP?
CHP is an energy efficient technology that generates electricity and captures the heat that
would otherwise be wasted to provide useful thermal energy - such as steam or hot water -
that can be used for space heating, cooling, domestic hot water and industrial processes. A
CHP system can be located at an individual facility or building, or be a district energy or utility
resource. CHP is typically located at facilities where there is a need for both electricity and
thermal energy. (Source: Combined Heat and Power Partnership, EPA)
Nearly two-thirds of the energy produced (or obtained) by conventional electricity generation
is wasted in the form of heat discharged to the atmosphere. Additional energy is wasted
during the distribution of electricity to end users. In contrast, in a combined heat and power
process, the vaporizing heat input happens only once and the sensible heat (condensing heat)
is used in the heating process. The total fuel efficiency of this combined process is then much
better than the one for separate processes. By capturing and using heat that would otherwise
be wasted, and by avoiding distribution losses, CHP can achieve efficiencies even over 80 %.
CHP applications cover a wide range of technology. Smaller heat demands are met by fuel
cells, internal combustion engines, Stirling engines and so on. For higher demands solutions
gas turbines, back pressure turbines and steam turbines with extractions are in use for CHP.
Its important significance is to improve energy efficiency by changing the production process
of equipment, and at the same time enrich the types of products.

Two most typical CHP system configurations are:
• Steam boiler with steam turbine (as shown in Figure 1)
• Combustion turbine, or reciprocating engine, with heat recovery unit (as shown in
Figure 2)
Figure 1 –CHP based on steam turbine
With steam turbines, the process begins by producing steam in a boiler. The steam is then
used to turn a turbine to run a generator to produce electricity. The steam leaving the turbine
can be used to produce useful thermal energy. These systems can use a variety of fuels, such
as natural gas, oil, biomass, and coal.

Figure 2 – CHP based on combustion turbine or reciprocating engine
Combustion turbine or reciprocating engine CHP systems burn fuel (natural gas, oil, or biogas)
to turn generators to produce electricity and use heat recovery devices to capture the heat
from the turbine or engine. This heat is converted into useful thermal energy, usually in the
form of steam or hot water.
– 12 – IEC TR 63388:2021 © IEC 2021
In this system configuration, the engine or turbine could be named the prime mover. It might
be gas turbine, fuel cells, internal combustion engines, Stirling engines, micro turbine and so
on.
3.2 Benefits of CHP
Energy conservation and emission reduction is an urgent issue for the whole world. With the
growth of the world population and the rapidly increasing consumption of non-renewable
energy, energy security and environmental protection are ever more important. The United
Nations sustainable development goals (SDGs) include ensuring affordable, reliable and
sustainable modern energy for people all over the world. CHP is an effective way to alleviate
these problems.
CHP is an efficient and clean approach to generating power and thermal energy from a single
fuel source. The average efficiency of fossil-fueled power plants in USA is 33 %, and has
remained virtually unchanged for decades. This means that two-thirds of the energy entering
the system is lost as waste heat. However, CHP systems typically achieve total system
efficiencies of 60 to 80 %. CHP can effectively reduce the condensation heat loss of working
fluid in thermal cycle; thus, less fuel is required to produce a given energy output than with
the separate production of heat and power. Figure 3 shows an example revealing the extent
to which CHP improves energy efficiency. (Source: Combined Heat and Power Partnership,
EPA)
Figure 3 – Example of energy efficiency for different generating systems
NOTE This is just an example quoted from EPA website of America, which aims to illustrate the advantages of
CHP system. The efficiency data mentioned in this figure do not necessarily represent the level of other countries.
Whether in developed or developing countries, the direction of energy system development is
to effectively meet energy demand on the premise of reducing total energy consumption. At
present, CHP has become one of the most important ways to achieve this goal.
Generally speaking, CHP is an optimal way of energy utilization. CHP offers a number of
benefits compared to conventional electricity and thermal energy production, including:
• Efficiency Benefits: CHP system requires less fuel to produce a given energy output and
avoids transmission and distribution losses that occur when electricity travels over power
lines.
• Environmental Benefits: Because less fuel is burned to produce each unit of energy
output, CHP reduces emissions of greenhouse gases and other air pollutants. Because
water evaporation is reduced in recirculated water systems, CHP contributes to water
conservation.
• Economic Benefits: CHP system can save facilities considerable money on their energy
bills due to its high efficiency, and it can provide a hedge against electricity cost
increases.
• Reliability Benefits: CHP system can be designed on-site to support continued
operations in the event of a disaster or grid disruption by continuing to provide reliable
electricity. It is a beneficial supplement to the traditional power production and is
conducive to improving the reliability of energy supply.
• Flexible operation Benefits: Small-scale distributed CHP system can be flexibly and
nearby configured according to the energy demand. It can supply a variety of different
energy, and can meet the requirements of fast start and stop. Therefore, it has the
advantage of flexible operation.
3.3 Efficiency of CHP system
CHP application involves the recovery of heat that would otherwise be wasted. In this way,
CHP increases fuel-use efficiency.
Two normal measures are provided to quantify the efficiency of a CHP system: total system
efficiency and effective electric efficiency.
• Total system efficiency is the measure used to compare the efficiency of a CHP system to
that of conventional supplies (the combination of grid-supplied electricity and useful
thermal energy produced in a conventional on-site boiler). If the objective is to compare
CHP system energy efficiency to the efficiency of a site's conventional supplies, then the
total system efficiency measure is likely the right choice.
• Effective electric efficiency is the measure used to compare CHP-generated electricity to
electricity generated by power plants, which is how most electricity is produced. If CHP
electrical efficiency is needed to compare CHP to conventional electricity production (i.e.
grid-supplied electricity), then the effective electric efficiency metric is likely the right
choice.
The total system efficiency (η ) of a CHP system is the sum of the net useful electric output
o
(W ) and net useful thermal output (ΣQ ) divided by the total fuel energy input (Q ), as
e TH FUEL
shown below:
W +ΣQ
e TH
η =
o
Q
FUEL
Note that this measure does not differentiate between the value of the electric output and the
thermal output; instead, it treats electric output and thermal output as having the same value
which allows them to be added.
In reality, electricity is considered a more valuable form of energy because of its unique
properties. Therefore, another efficiency calculation method is given.
Effective electric efficiency (ξ ) can be calculated using the equation below, where W is the
EE e
net useful electric output,ΣQ is the sum of the net useful thermal output, Q is the total
TH FUEL
fuel energy input, and α equals the efficiency of the conventional technology that would be
used to produce the useful thermal energy output if the CHP system did not exist:

– 14 – IEC TR 63388:2021 © IEC 2021
We
ξ =
EE
Q −Σ()Q
FUEL TH
For example, if a CHP system is natural gas-fired and produces steam, then α represents the
efficiency of a conventional natural gas-fired boiler. Typical boiler efficiencies are 80 % for
natural gas-fired boilers, 75 % for biomass-fired boilers, and 83 % for coal-fired boilers.
The calculation of effective electric efficiency is the CHP net electric output divided by the
additional fuel the CHP system consumes over and above what would have been used by a
boiler to produce the thermal output of the CHP system.
However, none of the proposed efficiency formulations enables a proper evaluation and
comparison of the technical level of the equipment in terms of the efficiency of the conversion
of thermal energy into electrical energy. If all low-potential heat is preserved and utilized as
net useful thermal output, then values of both the proposed efficiencies will be close to 100 %,
regardless of the proper efficiency of the conversion of thermal energy into electricity.
Therefore, as a compromise, other definition of thermal efficiency is needed, such as the
definition adopted by PURPA ("Public Utility Regulatory Policy Act" approved by the US
Congress in 1979). It formally attributes the heat produced only by one-half and thus takes
into account the lower quality of the supplied head compared to the electricity – both in terms
of energy and price (value).
W +⋅ΣQ
e TH
η =
PURPA
Q
FUEF
From a global perspective, there is a need for development of a standardized set of formulas
valid for all types of CHP schemes – process, district heating, process heating, cold or warm
heating, etc. – and for all kind of power generating systems which are present. That set shall
enable a comparison, evaluation and verification of the performances between all the different
applications.
4 Market situation of cogeneration
4.1 Global situation
In 2016, the total installed capacity of global CHP reached 755 GW. Among them, 46 % are
installed in the Asia-Pacific region(mainly in China and Japan), 39 % are installed in
Europe(mainly in Russia), and 15 % are installed in the Middle East, Africa and other regions
(mainly in North and South Africa). By 2025, the global CHP capacity is expected to increase
to 972 GW (an average annual growth of 2,8 %). Europe is the traditional market of CHP, and
Asia-Pacific is the main growth market of CHP.
4.2 European situation
In June 2018, Cogen Europe published a report entitled "The role of cogeneration in Europe's
future energy system", which introduced the development blueprint of European cogeneration
to 2050. Cogeneration currently provides 11 % of electricity and 15 % of heat for Europe,
contributing to the EU's 21 % CO2 emission reduction target and 14 % energy efficiency target.
By 2030, CHP will provide 20 % of electricity and 25 % of heat energy for Europe, and at least
one third of CHP will come from renewable energy, which will contribute to the EU's 23 % CO2
emission reduction target and 18 % energy efficiency target. By 2050, the European Union is
expected to double the proportion of cogeneration in the overall power generation, and make
the cogeneration industry the top priority in energy development.
The EU's development of CHP focuses on the application of renewable energy and small-
scale distributed energy system to meet decentralized user needs, while achieving the best

economic efficiency and energy efficiency. The share of renewable energy in CHP in EU has
increased from 15 % in 2010 to 21 % in 2015, and the main fuel used is natural gas (44 % of
CHP fuels in 2015).
Russia has rich experience in CHP. As early as in the age of Soviet Union, CHP was widely
used. At that time, a large number of CHP units were installed in cities and large industrial
centres to achieve economic heating in cold weather. Today, in Russia, CHP power plants still
account for more than one-third of domestic electricity production, and nearly one-half of
heating production.
Compared with thermal power plants, a distributed energy system is easier to realize flexible
operation. According to the experience of some European countries, many small distributed
units can be used to replace large CHP units and make them closer to energy users, so as to
improve the energy efficiency. At present, the distributed CHP system is very popular in some
European countries.
4.3 American situation
According to the statistics of the US Department of energy, by the end of 2018, the total
installed capacity of cogeneration in the United States was 81,09 million KW, accounting for
19,43 % of the total power generation. From 2000 to 2018, the scale of cogeneration in the
United States increased by 57,37 %, the installed capacity increased from 51,53 million kW to
81,09 million KW, and the number of power stations reached 5 637. Among them, the installed
capacity of CHP with natural gas as raw material reached 58,0 389 million KW, accounting for
71,57 % of the total installed capacity of CHP; natural gas projects account for 68,38 % of the
total quantity of cogeneration.
4.4 Asian situation
In the Asian region, China and Japan have the biggest CHP markets.
China has a huge quantity of CHP cases, and its technology development and application are
very representative.
Figure 4 shows the proportion of different heating modes in urban areas of northern China.
Coal-fired CHP accounts for 45 % of the heating area. Coal-fired boilers account for 32 %.
Gas-fired boilers account for 11 %. Gas wall-mounted furnaces account for 4 %. Gas-fired
CHP accounts for 3 %. In addition, there are electric boilers, various types of electric heat
pumps (air source, ground source, and sewage source), fuel oil, solar energy, biomass and
other forms of heat sources, a total of 5 %. (Source: Current Situation of Clean Heating in
Winter in Northern Cities and Towns of China, by Liu Rong)
Further expansion of CHP will be one of the most important measures to alleviate haze
weather in northern China.
– 16 – IEC TR 63388:2021 © IEC 2021

Figure 4 – Proportion of different heating modes in urban areas of northern China
In addition to district heating, there is also a large demand for industrial heat supply. Industrial
production, including chemical industry, papermaking, pharmaceuticals, textiles and non-
ferrous metal smelting, requires the use of a large amount of high-temperature steam. At
present, some large industrial enterprises supply steam by their own thermal power plants,
and many enterprises supply steam by boilers. This leads to a very low efficiency of energy
use.
Due to the requirements of environmental protection, industrial small boilers with high energy
consumption and heavy pollution will be shut down gradually. In the future, industrial parks
will be encouraged to concentrate industrial users, while CHP units with high efficiency and
qualified emissions will be responsible for industrial heat supply. This will become the
mainstream in China.
Unlike China, which relies mainly on coal, Japan has built a lot of cogeneration units with fuel
of natural gas and oil. Table 1 shows the installed capacity of cogeneration units in Japan as
of March 2020. It is classified according to the fuel. Figure 5 shows the percentage of
installed capacity of different cogeneration units by fuel types. (Source: Advanced
Cogeneration and Energy Utilization Center JAPAN)
Table 1 – Installed capacity of cogeneration units in Japan as of March 2020
Fuel Types Commercial(MW) Industrial(MW) Total(MW)
Natural Gas 1 799 5 852 7 651
LPG 51 418 469
Oil 719 2 973 3 693
Others 99 1 063 1 162
Total 2 669 10 306 12 975
...