the fossil-fired power plants of enbw
Post on 22-Apr-2015
128 Views
Preview:
TRANSCRIPT
EnBW Energie Baden-Württemberg AG
Turning primary energy efficiently into electricityThe fossil-fired power plants of EnBW
Turning primary energy efficiently into electricityThe fossil-fired power plants of EnBW
Competitive and fit for futureEnergy generation at EnBW 4
Acting sustainably and responsiblyEnvironmental protection at EnBW 8
Conventional power plant fleet
High importance for the regional economyAltbach/Deizisau heat and power plant 12
Valuable energy from waste and coalStuttgart-Münster heat and power plant 16
Full performance within minutesStuttgart-Gaisburg heat and power plant 18
Biggest coal-fired unit in the EnBW power plant fleetHeilbronn heat and power plant 20
Back up for demand peaksWalheim power plant 22
Contents
2
Airplane turbines for power generationMarbach power plant 23
High performance, efficient and innovativeRheinhafen steam power plant in Karlsruhe 24
Holdings and electricity procurementBexbach power plant 30
Lippendorf power plant 31
Rostock power plant 32
Buschhaus power plant 33
Stadtwerke Düsseldorf municipal utility 34
Grosskraftwerk Mannheim power plant 35
The technology of a power plant
Technology made easyHow fossil-fired power plants work 38
Stable and flexibleThe electricity network of EnBW 46
Glossary 48
Plant tours 52
Publishing details 53
3
EnBW believes that a balanced electricity
generation mix forms the basis for the re-
liable, competitive and environmentally
sound supply of energy to Germany as an
industrial location. This mix com prises the
increased use of renewable forms of energy,
supplemented by supplies from reliable
nuclear power plants and the
efficient use of the available fossil fuels
lignite, coal and gas.
EnBW's own power plant fleet with its core
locations on the Rhine and Neckar rivers is
backed up by holdings and procurement
agreements, some of them with suppliers
outside the home market of Baden-Würt-
temberg. EnBW makes use of the "South
Unit" of the Lippendorf lignite power
plant, for example, operates a power plant
in Rostock and receives power supplies
from the facility in Buschhaus. EnBW's
strategic position in the German power
generation market is underpinned by an
output volume of around 15,000 mega-
watts (MW).
The power plants in the EnBW portfolio
are always in line with the state of the art:
efficient operating and maintenance con-
cepts drawing on the experience of opera-
ting teams and engineers stretching back
over several decades and ongoing optimi-
sation and modernisation measures en -
sure that the facilities are equipped to
meet the energy generating challenges of
the coming decades.
Together with high safety and environ-
mental standards, it is this strategy that
enables us to meet the growing demands
in terms of the availability, efficiency and
above all flexibility of our power plants.
Energy mix of the future
On the road to a supply system primarily
based on renewable forms of energy, the
use of high-availability coal and gas power
plants will continue to play an important
role for decades to come – particularly in
global terms – as it is these facilities that
provide the necessary balance to con-
stantly cover the residual load resulting
from the gap between the demand for
electricity on the one hand and the fluc-
tuating volume of power generated from
renewable sources on the other. Indeed,
these so-called back up power plants need
to be able to meet the entire load demand
at times when there is no wind and simul-
taneously little or no sunshine. In the case
of the plants used as baseload and inter-
mediate load power plants, the number of
hours during which they operate at full
power will tend to fall more rapidly than
the volume of electricity they feed into
the grid.
Competitive and fit for futureEnergy generation at EnBW
4
In its energy concept "2020", the state
government of Baden-Württemberg de -
fined its energy mix using the formula
50/30/20, which translates into a genera-
ting structure supplying 50% of electricity
from nuclear power and 30% from fossil
fuels while increasing the share of renewa-
bles in overall generating volume to 20%.
EnBW supports this target laid out by the
state government.
In view of the need for grid stability and
the provision of reactive power, controll -
able conventional power plants constitute
key elements in the electricity supply sys -
tem. In terms of number and geographic
location, they need to be distributed based
on the peak demand load areas through -
out the network so that they ensure the
supply of electricity close to the point of
consumption.
In order to develop the cornerstone of the
EnBW business portfolio – namely the gen -
eration of electricity – as the core strate -
gic element in the long term, EnBW is
currently building two state-of-the-art
coal-fired power plant units in the 900-
megawatt class: these investments at the
Rheinhafen plant in Karlsruhe (unit 8)
and at the Gemeinschaftskraftwerk Mann-
heim plant (unit 9), in which EnBW holds
an interest, are both designed to replace
older plants.
5
Rostock(Mecklenburg-West Pomerania)(Mecklenburg-West Pomerania)
GlattNeckar
Fils
Danube
Iller
Argen
Aach
Elz
Rhine
Murg
Enz
Nagold
Itter
Main
JagstKocher
Iller power plants
Austria
Switzerland
France
Obrigheim1
Heilbronn
Neckarwestheim
Walheim
Marbach
Altbach/DeizisauGaisburg
Stuttgart-Münster
Glems
Schluchsee power plants
Fessenheim(France)
Forbach
Karlsruhe
26 Neckar power plants
Mannheim
PhilippsburgBexbach(Saarland)
Cattenom(France)
Lippendorf (Saxony)
Pforzheim
Vorarlberger Illwerke power plants
High Rhine power plants(Germany/Switzerland)
Buschhaus(Lower Saxony)
Upper Danube power plants
Operations ceased on 11 May 2005 as a result of the nuclear energy agreement in Germany.
1
Ulm
Freiburg
Stuttgart
Karlsruhe
Hydroelectric plants on the Kocher river
Hydroelectric plants on the Jagst river
Baden-Baden
Rhine power plants(CERGA/RKI)
Conventional power plantoperated by EnBW
Nuclear power plantoperated by EnBW
Conventional power plant with EnBW holding,purchase or supply agreements
Nuclear power plant withpurchase or supply agreements
Hydroelectric power plantoperated by EnBW
Hydroelectric power plant with EnBW holding,purchase or supply agreements
The power plant fleet of the future
The sparing use of fossil fuels and the ef-
fective reduction of emissions that impact
our climate is more important than ever
before. One of the levers that energy sup-
pliers worldwide can apply in order to cut
CO2 emissions is the development of eco-
nomical, highly efficient power plants for
the generation of electricity. The efficien-
cy level plays a key role in this respect; it is
an indicator for the efficiency with which
a power plant uses the fed-in energy
sources. Today, new power plants can
achieve efficiency levels of more than 45%.
If we succeed in increasing this figure
even further, we can reduce the volume
of coal input needed to create the same
energy output and therefore also cut CO2emissions.
With carbon capture and storage (CCS), a
new technology is coming to the fore that
can reduce emissions from industrial and
power plant processes and therefore make
a valuable contribution to climate protec-
tion. CCS is an important topic for EnBW,
and we are already preparing our new
power plants for the use of this techno -
logy. One example of this is the new con-
struction of unit 8 at the Rheinhafen
steam power plant, where the necessary
space is being reserved for the possible in-
tegration of a CO2 capture system. We are
also currently building a test facility at
our power plant location in Heilbronn to
test CO2 capture using an aqueous amine
solution.
The power plant fleet of the future needs
to be more flexible. This means that ex -
isting and future plants should start up
rapidly, cover as wide a partial load range
as possible and be able to vary their out-
put in high gradients (load change capa -
bility). As gas-fired power plants meet this
criterion, EnBW is looking into projects of
this kind at locations like Lubmin or in
Düsseldorf together with the city's muni-
cipal utility.
Storage power plants will also play an in-
creasingly important role in the future
generating system, as pumped-storage
concepts are currently the most efficient
and flexible way to store large quantities
of electricity that can be called on at ex -
tremely short notice. This stabilises the
grid and offsets the fluctuations in supplies
generated from renewable sources.
6
Emissions trading and reduction targets
In line with the stipulations of the Kyoto
Protocol, climate-damaging CO2 emis -
sions from the energy-intensive sectors of
the industrial nations can first be capped
and then traded based on supply and
demand. This means that states or com -
panies within these states trade their allo-
cated emission allowances within the EU.
These so-called CO2 certificates are sold
by states or companies whose production
operations are particularly efficient and
who therefore do not fully utilise the quo-
tas that have been allocated to them – and
they are sold to counterparts who have
emitted a greater amount of CO2 than
they are permitted to based on the offici-
ally agreed environmental targets.
This overall mechanism creates an incen-
tive to save CO2 and has the added effect
that capital used to reduce CO2 emissions
can be invested above all in places where
the measures are effective and cost-effi-
cient. In addition, it promotes a willing-
ness to invest in research and innovation
geared towards the improvement of
power plant efficiency. As an energy-
intensive company, EnBW takes part in
the system of emissions trading and op -
timises its plants on an ongoing basis.
The Kyoto Protocol also allows companies
to achieve a part of their reduction targets
by implementing improvements to facili-
ties in developing countries and econo-
mies in transition. This helps to reduce the
emission of greenhouse gases; in other
words, it results in certified emission re-
ductions. This system is known as the
Clean Development Mechanism (CDM). As
the greenhouse effect is a global pheno-
menon, the funds invested in projects of
this kind have a particularly important ef-
fect when it comes to reducing emissions,
as it is irrelevant whether these emissions
are reduced in Germany or, for example,
in Kenya or Peru.
EnBW develops its own CDM projects on
various continents and using a wide range
of different technologies – including wind
farms, biogas generation, hydropower or
landfill gas incineration. In order to ach ieve
the ambitious goals, various units at EnBW
– such as the holding company, the power
plant company or the trading division –
have pooled their core expertise.
7
For EnBW, sustainable action means at -
taching equal importance to its economic,
ecological and social responsibilities.
EnBW was the first German energy com -
pany to introduce a group-wide environ-
mental management system certified in line
with ISO 14001 and has continued to ex-
pand this system in recent years. In July
2010, this 14001 certification covered the
entire value added chain including conven-
tional power generation: in absolute terms,
the system covers 25 companies or around
98% of the approx. 20,000 employees of
the EnBW Group. The certification of fur -
ther companies is scheduled up to the end
of 2011.
Compliance with the internationally valid
ISO 14001 requirements and certification
were both performed on a voluntary basis,
underlining the key importance attached to
the issue of environmental protection at
EnBW and serving as a further example of
the pioneering role played by EnBW in this
area.
The environmental management system
reviews all environmentally relevant pro-
cesses and installations to determine their
actual and potential impact on the environ-
ment. All responsibilities and interfaces are
clearly defined.
The core focus of ISO 14001 is the continu-
ous improvement of both the environmen-
tal performance of the company and its en-
vironmentally relevant processes. To this
end, group-wide environmental targets
were defined for the following topics for
the period from 2008 to 2010:
› Climate protection, saving use of re-sources, energy efficiency,
› Sustainable social responsibility,› Communication and raising awareness› Protection of mankind and the environ-ment.
Acting sustainably and responsiblyEnvironmental protection at EnBW
1 The generation portfolio includes long-term procurement agreements and generation from partly owned
power stations.2 In anticipation of the change in the method of transfer of renewable energies under the EEG as of 2010
(financial instead of physical transfer), as of fiscal 2009 the quotas are reported on the basis of the
electricity generated in the EnBW Group’s own facilities without taking into account any supplies of EEG
electricity (prior-year values were restated).3 By analogy to the disclosure pursuant to Sec. 42 German Energy Industry Act (EnWG)
8
Energy generated by the EnBW Group1
by primary source of energy2 in % 2009 2008 2007
Conventional energy 27.6 28.2 29.7Nuclear energy 57.2 56.8 54.1Renewables3 10.6 10.8 9.9Other 4.6 4.2 6.3
As the company responsible for operating
the conventional generating plants, EnBW
Kraftwerke AG has addressed these topics
and formulated four environmental prin-
ciples:
› Through our actions we ensure the pro-tection of mankind and the environ-
ment.
› As a generating company in the EnBWGroup, we are under a particular obliga -
tion to fulfil our environmental responsi-
bilities in a farsighted and active manner –
also in the competitive arena. In doing so,
we adhere to the environmental princi-
ples of the Group.
›We operate our facilities in a way thatspares the environment and aim at mini-
mising the burden on air and water with -
in the constraints of our operational re-
quirements.
›We strive to constantly improve our ef-forts for the environment’s sake. In parti-
cular, this also includes fostering the en-
vironmental awareness of our employees
and of the external contractors who we
commission to perform work on our be-
half.
2004
2005
2006
2007
2008
2009
D-20081
150
170
140
140
131
156
280
Specific sulphur dioxide (SO2) emissions from 2004 to 2009 in mg/kWh
2004
2005
2006
2007
2008
2009
D-20081
145
170
165
173
159
400
158
Specific nitrogen oxide (NOx) emissions from 2004 to 2009 in mg/kWh
2004
2005
2006
2007
2008
2009
D-20081
225
250
240
254
241
506
235
Specific carbon dioxide (CO2) emissions from 2004 to 2009 in g/kWh
1 Comparison data for German electricity mix, 2008 (source: German Association of Energy and Water
Industries, BDEW)
9
Conventional power plant fleet
Location
The Altbach/Deizisau combined heat and
power plant (CHP) is an important econo-
mic factor in the central Neckar region
and guarantees the reliable, cost-effective
and environment-friendly generation of
energy. EnBW operates several units at
this location with a total installed capacity
of approximately 1,292 megawatts. The
two units of the CHP plant are coal-fired
and can simultaneously produce electrici-
ty and district heat. In addition, there are a
combined gas and oil unit and two gas tur-
bines at the location.
The Altbach/Deizisau power plant feeds
its electricity into both the 400-kilovolt
very-high voltage network and the 110-ki-
lovolt high-voltage network and supplies
the Stuttgart-Plochingen district heat line.
History
In 1899, a water-powered plant was cre-
ated on the Neckarkanal waterway, which
had been built specifically for this purpose.
The construction of the "Kraftcentrale Alt-
bach" installation was commissioned by
Heinrich Mayer, whose aim was to supply
electric energy to the Neckar and Fils
valley. The first community supplied with
electricity from the "power plant" was
Obertürkheim. The electricity network
continued to grow and further communi-
ties followed. From 1902 onwards, the
company operated under the name
"Neckarwerke Altbach/Deizisau Heinrich
Mayer". It was transformed into a stock
corporation three years later. Then, Neckar -
werke Elektrizitätsversorgungs-AG based in
Esslingen merged with Technische Werke
der Stadt Stuttgart AG , and in 2003 the ac-
tivities and know-how of the Neckarwerke
High importance for the regional economyAltbach/Deizisau heat and power plant
View of the Altbach/Deizisau heat and power plant
12
Stuttgart AG (NWS) company created by
this alliance were merged with the exper-
tise of EnBW. Back in the seventies, the
plant was thoroughly modernised and re-
structured, and aspects such as energy ef-
ficiency, environmental protection, land-
scaping, nature conservation and architec-
ture played a key role in this process. The
first step was to replace section I of the
plant with CHP plant 1, which went into
operation in 1985. When CHP plant 2 was
built at the end of the eighties to replace
the three units of plant section II, the de-
sign successfully integrated the power
plant buildings in the surrounding land-
scape, creating a plant equipped with ad-
vanced environmental technology at the
edge of a public park.
Special features
Hybrid cooling towerBy combining wet and dry cooling meth -
ods, the hybrid technology allows low
structural heights and ensures greatly re-
duced plume formation.
First, the cooling water gives off part of its
waste heat to the air via finned tubes. It
then falls down into the cooling tower bas -
in in the form of a drizzle, where it cools
further as a result of evaporative cooling,
while giant fans press the cooling air
through the wet and dry sections. Moist
and dry air mix in the top third of the
cooling tower, and this prevents nearly
all plume formation.
During the day, the cooling tower is always
operated in hybrid mode (i.e. wet section
and dry section together) in order to mini-
mise plume formation. At night the fans
of the dry section are switched off, reduc -
ing the self-consumption of the power
plant and therefore increasing efficiency
levels.
Combined heat and power plant 2 (CHP 2)
is controlled from the central control
room
13
Compound unitThe technical concept of the combined
heat and power plants (CHPs) is deter-
mined by ecological and economic require-
ments. A high utilisation level allows effi-
cient use of the fed-in primary energy.
While CHP 1 is designed for a conventional
steam turbine process, CHP 2 is additio-
nally fitted with a gas turbine, which is
linked on the water/steam side with the
coal-fired unit. Depending on electrical
and thermal output requirements, this
combination unit achieves a fuel utilisation
rate of up to 70%.
Highly efficient systems for denitrifica -
tion, dedusting and desulphurisation sit -
uated downstream of the steam generator
clean the flue gases, removing nitrogen
oxides, dust and sulphur dioxide. The
extraction of district heat, which practically
replaces numerous industrial and private
heating systems, additionally helps to
minimise pollutant emissions.
Main transformer of combined heat and power plant 2 (CHP 2)
14
The central laboratoryThe central laboratory of EnBW Kraftwerke
AG was set up in 2004 at the Altbach/Dei-
zisau location. The lab is a competence
centre pooling the corporate know-how in
the fields of power plant chemistry, oil
analysis and organic analysis as well as
trace element and heavy metal analysis. It
is also responsible for catalytic converter
management at the power plants. With its
state-of-the-art equipment, the central
laboratory is ideally placed to handle key
chemical issues not just within but also
beyond the EnBW Group.
Technical data
Year built: 1899Units: 2 coal units (1 coal, 1 compound unit)
2 gas turbine systems1 gas-oil compound block in cold reserve
Gross electrical rating: 1,215 MWelExtractable district heat output: 210 MWth
15
The EnBW central lab in Altbach/Deizisau
Location
The Stuttgart-Münster heat and power plant
is a unique facility in the EnBW power plant
fleet: the main purpose of the plant is not to
generate electricity but to handle the ther-
mal treatment of waste and to produce dis -
trict heat. Electricity and district heat are
produced simultaneously in Stuttgart-
Münster based on the cogeneration principle
in order to ensure improved fuel utilisation.
The heat and power plant comprises three
coal boilers, a waste incineration system
with three waste boilers, three steam tur -
bines and a gas turbine system. All in all, this
location has an electrical capacity of 184 MW
and a district heat capacity of 447 MW.
Two new waste boilers were built and put in-
to service in 2007. The processing capacity
of the waste-fired heat and power plant to-
tals 420,000 tons a year (reference calorific
value: 11,000 kJ per kg). In this way, EnBW
makes a key contribution to the reliable, en-
vironment-friendly and cost-effective dis-
posal of residual waste in Baden-Württem-
berg.
The contractual basis for these operations
dates back to 2003, when the city of Stutt-
gart and the Esslingen and Rems-Murr ad-
ministrative districts signed a disposal
agreement with EnBW Kraftwerke AG. Ac-
cording to this agreement, the city of Stutt-
gart and the two districts deliver around
225,000 tons of waste to Münster every
year. T-plus GmbH, a company belonging to
EnBW's disposal division, can draw on an
additional 185,000 tons of incinerating ca-
pacity. This EnBW subsidiary also disposes
of residual municipal waste in the Stuttgart
heat and power plant – this waste comes
from places like the Lake Constance admi-
nistrative district and the Reutlingen/Tü-
bingen region.
Valuable energy from waste and coalStuttgart-Münster heat and power plant
The Stuttgart-Münster heat and power plant on the Neckar
16
History
In 1908, the power plant began generating
electricity to meet the growing energy
demand in the region under the name
"Dampfkraftwerk des städtischen Elektrizi-
tätswerks" (steam power station of the mu-
nicipal electricity works). From 1933 until
the 1970s it also generated traction current,
and it started producing district heat in co-
generation mode in 1935. The first district
heat customers were the mineral baths and
the hospital in the town of Bad Cannstatt.
The capacity of the power plant was also ex-
tended in the 1950s during the reconstruc-
tion of Germany: the waste incineration
plant went into operation in 1965, signal ing
the start of a new era in the history of the
location – the beginning of generation of
electricity and district heat from waste.
In the 1980s and 1990s, more stringent en-
vironmental protection requirements ne-
cessitated the construction of large-scale
cleaning systems for the flue gases result-
ing from the firing of coal and waste. First,
the catalytic denitrification systems for the
coal boilers went into service in 1986. These
were followed in 1988 by the flue gas desul -
phurisation system to clean the flue gases
from the coal boilers. Finally, in 1993, a
state-of-the-art flue gas scrubbing system
was started up to clean the waste gases
from the refuse incineration plant. On -
going optimisation work at the power plant –
such as the construction of the central
waste hopper in 1997 – ensures that the plant
in Stuttgart-Münster meets all the require-
ments for a modern waste disposal facility.
Special features
Flue gas cleaningThe flue gases produced by the waste incin -
eration process contain various pollutants
which need to be removed from the gases
before they leave the 180 metre-high stack.
Cleaning takes place in the flue gas cleaning
system, which consists of a dust separator, a
wet scrubber and a catalytic converter.
Both electric and fabric filters are used to
remove the dust. These filters can remove
up to 99% of the dust from the gases. In the
next stage, the dedusted flue gas flows
through a four-stage wet scrubber which
17
uses caustic soda to remove – primarily –
the hydrogen chloride, hydrogen fluoride,
sulphur dioxide, heavy metals, aerosols and
fine dust. A small amount of activated car-
bon is added to reduce dioxin levels and
bind the mercury. The separated pollutants
are extracted at the end of the process in
the form of dry salts and disposed of under-
ground. The catalytic converter – the third
stage of the cleaning process – is where the
remaining organic components, in particu-
lar any remaining dioxins and furans, are
denitrified and destroyed by oxidisation.
Back-pressure turbineAt the end of 1999, a back-pressure turbine
went into operation to supplement the two
extraction condensation turbines. The tur-
bine reduces the pressure of the steam in
the boiler to 4.5 bar – so that it can be fed in
to the heat exchangers for the district heat
system – and also drives an electric genera-
tor (18.5 MW).
Technical data
Year built: 1908Units: 1 coal unit with 3 coal boilers and 3 waste boilers
1 gas turbine systemGross electrical rating: 184 MWelExtractable district heat output: 447 MWth
Location
The Stuttgart-Gaisburg CHP plant is located
on the left bank of the Neckar river in the
suburb of Gaisburg. The characteristic
features of the plant are the two adjacent
stacks measuring 160 and 125 metres in
height.
The complex consists of two power plant
units and a gas turbine system. The power
plant is used almost exclusively to generate
district heat and is the location of EnBW's
only fluidised bed boiler.
In December 2009, a 22-MW district heat
back-pressure turbine was installed at the
Stuttgart-Gaisburg power plant. The waste
steam (6 bar) from the turbine heats the
district heat water for three different net-
works via heat exchangers.
History
The older of the two current power plant
units went into commission as a coal-fired
common-heater heat and power plant in
1950 and is today designated as unit 2. In
1958, the Heizkraftwerk Stuttgart GmbH
company leased the plant to Technische
Werke der Stadt Stuttgart AG, one of the
four predecessor companies of EnBW.
Special features
Fluidised bed boilerIn this boiler type, a mixture of ash, coal and
lime is fluidised in an air stream and then
burnt. The special feature of this technology
is the direct addition of lime, which directly
binds the pollutants created in the combust-
ion chamber. This ensures compliance with
the stipulated emission limits with out the
need for secondary flue gas cleaning systems.
Full performance within minutesStuttgart-Gaisburg heat and power plant
Gaisburg is only a few kilometres downriver of the Münster location.
18
Gas turbineThe 60-MW gas turbine in power plant 1 is
primarily designed to secure electricity
supplies in the event of the failure of other
plants but is also used to cover peak loads.
The only fuel still used today is natural gas.
Following a normal start-up, the gas turbine
reaches full power after around eight min -
utes; after a rapid start-up it is fully up and
running after just under five minutes. A
diesel assembly ensures that the turbine is
black start capable; in other words that it
can be started up without any outside ener-
gy in the event of a complete network black
out.
19
Technical data
Year built: 1950Units: 1 coal unit
1 gas turbine system1 unit in cold reserve
Gross electrical rating: 194 MWelExtractable district heat output: 273 MWth
Work on the compressor of the gas turbine
Location
The Heilbronn combined heat and power
plant is located in an industrial and commer-
cial estate on the outskirts of the town right
next to the Neckar river. The plant is opera-
ted in cogeneration mode and is one of the
biggest coal-fired power plants of EnBW
Kraftwerke AG with an electrical output of
over 1,000 MW and an extractable thermal
capacity of 320 MW. Three of the original
seven units are still in operation today.
Units 5 and 6 went into operation in the mid-
sixties and are today equipped with state-of-
the-art flue gas cleaning systems. Unit 7 com-
pleted in 1985 is the biggest coal-fired unit in
our entire conventional power plant fleet.
The plant was technically optimised by the
implementation of wide-ranging modernisa-
tion measures in 2009 and equipped to
meet the challenges of the coming decades.
The result? A permanent output boost of
around 40 MW and a further reduction in
CO2 emissions.
Unit 7 was the first coal-fired unit in Germa-
ny originally equipped with highly efficient
cleaning systems and therefore played a pio-
neering role in terms of environmental pro-
tection. Coal combustion produces air pollu-
tants like nitrogen oxides, dust and sulphur
dioxide. The use of efficient flue gas cleaning
systems (denitrification, dedusting and de-
sulphurisation) ensures that the pollutant
content in the flue gas is within the limits
set by legislation.
History
For more than 80 years, the Heilbronn loca-
tion has been a byword for coal-fired electri-
city generation – and for over 50 years also
for the reliable supply of district heat. The
first turbine sets went into operation in 1923
but soon had to compete with the hydro -
Biggest coal-fired unit in the EnBW power plant fleetHeilbronn heat and power plant
View of the Heilbronn heat and power plant on the Neckar
20
electric power plants in the surrounding
region. Then, in the early post-war period,
damage caused by wartime bombing led to
operational delays. A new era began in the
1950s, when planning work began on a new
large-scale power plant. A total of six power
plant units had been built by the mid-1960s:
units 1 and 2 were shut down in 1988 and
were followed by units 3 and 4 in 2006, but
the last two units are still in operation.
In 1960, the power plant supplied heating
steam to a nearby industrial facility for the
first time, and construction work on a dis -
trict heating network began just one year
later. A decision was made in the late 1970s
to build unit 7, which was completed in 1985.
Special features
Co-combustion of sewage sludgeSewage sludge has been co-combusted in
unit 7 since 1998, paving the way for envi-
ronment-friendly disposal with no pollu-
tants detectable in either the flue gas or
the incineration residues from power plant
operation. The co-combustion process is a
sustainable method of using the energy
contained in the sewage sludge to generate
electricity and district heat.
Training centreAt the Heilbronn power plant location,
young people have been trained for future
careers in the energy sector for more than
25 years. EnBW set up the centre (originally
housed in the mechanical workshop) back
in 1983 in response to the growing impor-
tance of company-based training pro -
grammes. The training centre was moder n -
ised in 2002 and extended in 2008.
21
Coal stockpile at the Heilbronn location
Technical data
Year built: 1923Units: 3 coal units
3 auxiliary steam generatorsGross electrical rating: 1,010 MWelExtractable district heat output: 320 MWth
Location
The Walheim power plant is also located
on the Neckar. It was built between 1962
and 1967 by Neckarwerke Elektrizitätsver-
sorgungs-AG and is equipped with two
coal-fired units. Unit 1 went into operati-
on in September 1964, unit 2 in August
1967.
History
In the winter of 1981/1982, a gas turbine
housed in a separate building and fired
with light fuel oil went into operation. As
it can be started up and begin feeding elec-
tricity into the network within a few minu-
tes, it is used to cover peak demand and al-
so serves as a reserve unit.
Environmental technology was retrofitted
to the two coal-fired units between 1987
and 1989 mainly for desulphurisation and
the reduction of nitrogen concentrations
in the flue gases.
When it fitted a nitrogen oxide reduction
system for a slag-tap boiler with ash
feedback, the company entered uncharted
technical territory; and the construction
of the system was therefore subsidised by
the German Environmental Agency. The
gas turbine was retrofitted in 1990 for low-
nitrogen oxide operation.
Unit 1 had been conserved and placed in
cold reserve back in April 2000. As part of
our reactivation measures for our power
plant fleet, we put the facility back into
operation in January 2005.
Back up for demand peaksWalheim power plant
Rapid availability when needed – the reserve and peak load plant in Walheim
22
Technical data
Year built: 1964Units: 2 coal units
1 gas turbine systemGross electrical rating: 391 MWel
Location
The EnBW power plant is located directly
on the Neckar a little way outside Marbach.
It went on line in 1940, and the units 2 and 3
meanwhile generate an output of 413 MW.
History
The coal-fired power plant was once the most
important power plant of Energie-Versorgung
Schwaben AG, a predecessor company of
EnBW. During the post-war period, it made a
key contribution to the economic upturn in
the region. As new, technically improved and
more cost-effective power plants were built in
other locations, the volume of electricity ge-
nerated in Marbach began to decline in the
1960s. Initially just the older installations and
soon the entire power plant was used as a re-
serve only. In 1981, the power plant unit Mar-
bach I was finally shut down.
In 1970, the unit Marbach 2 went into opera -
tion with a gas turbine plant powered by jet
turbines made by Rolls Royce. This plant is
still used today to generate peak load energy
and as a minute reserve.
Marbach 3 is an oil-fired gas and steam tur -
bine plant. When it was started up in 1974, this
combination unit was designed to cover in-
termediate load requirements. Following the
rise in oil prices and the introduction of a pol-
icy geared towards decreased dependency on
oil in the 1970s, however, the power plant
soon became a peak load plant and per -
formed the key generating reserve function.
Today, Marbach 2 and 3 are safety reserve
units – in other words, they need to be con-
stantly ready to go into operation.
In January 2005, the steam section of the fuel
oil-fired Marbach 3 unit went back into opera-
tion as part of modernisation and reactivation
measures. This section had been conserved
and shut down in 1998; only the gas turbine
was still in operation, generating elec tricity
in peak load periods when required.
23
Marbach – specialist for peak demand and minute
reserve
Airplane turbines for power generationMarbach power plant
Technical data
Year built: 1940Units: 1 gas turbine system
1 combination unitGross electrical rating: 413 MWel
Location
EnBW Kraftwerke AG operates the Rheinha-
fen steam power plant situated on the road
leading to the Rheinhafen port in Karlsruhe.
With a total installed electrical capacity of
1,260 MW and a maximum district heat ex-
traction volume of 220 MW, the power plant
plays an important and reliable role in the
cost-effective and environment-friendly
generation of electricity and district heat
within the EnBW power plant fleet.
The power plant went into operation in 1955
and today comprises four units: unit 4 is a
modern natural gas-fired plant with combi-
ned gas turbine and steam power processes.
The two oil- and gas-fired units 5 and 6 have
been operating in cold reserve since 1993.
The biggest unit at the Rheinhafen facility is
the coal-fired unit 7, which has been generat -
ing not just electricity but also district heat
since 1985. The plant received the certificate
for the European eco-audit in July 2000 and
was the first coal- and gas-fired power plant
in Germany to be awarded this certification.
A new unit has been under construction at
this location since the spring of 2008. Build -
ing work on the coal-fired unit 8 is on sche-
dule, and when it goes into operation it will
be possible to feed a maximum 220 MW of
thermal output in the form of extracted dis -
trict heat into the district heat network of
the city of Karlsruhe.
High performance, efficient and innovativeRheinhafen steam power plant in Karlsruhe
Energy for the Karlsruhe economic region – the power plant in the Rheinhafen port
24
History
By the late 1940s, planning had already be-
gun for the construction of a power plant in
Karlsruhe. The aim was to meet the rising
demand for electricity resulting from the
economic upturn and to reduce dependence
on power procured from other suppliers.
The location selected for the plant was a site
in the southern "Maxauer Rheinaue" district
on the Rhine, which created ideal conditions
for the operation of a power plant: direct
delivery of coal by waterway, the ability to
meet cooling water requirements for the
once-through cooling system by creating a
direct link to the Rhine and the option of
feeding electricity into the European inter-
connection grid via the transformer station
in nearby Daxlanden.
Units 1 and 2 went into operation in Februa-
ry 1955 and were followed by units 3 and 4 at
the beginning of the 1960s. In order to be
able to meet the growing demand for elec-
tricity in the years that followed, Badenwerk
AG – a predecessor company of EnBW – built
a number of additional power plant units:
the gas and oil-fired units 5 and 6 were com-
pleted in 1967/68, and the next milestone in
the history of the Rheinhafen power plant
was the construction of unit 7 in 1985. After
this unit was completed, units 1 to 4 were la-
ter shut down and units 5 and 6 used in cold
reserve mode. Unit 4 was repowered in 1997,
when it was converted from a coal-fired
plant into a combined cycle plant.
Today, units 7 and 4 are the key components
in the Rheinhafen power plant in Karlsruhe;
together with units 5 and 6, they have a total
installed capacity of 1,260 MW.
25
Work on a coal mill in unit 7
Gas turbine in unit 4
Special features
CoolingThe power plant units are not cooled
using a cooling tower but by a process
known as direct cooling. The cooling water
is taken from the Rhine river, mechanical-
ly cleaned and routed through the con-
denser. When it flows back into the river, it
is at most 10 degrees Celsius warmer than
when it was taken out. The Rhine carries
around 1,100 m3 of water per second on
average – and still carries over 500 m3
when average water levels have already
been low for many years. Before the cool -
ing water enters the system, it is mecha -
nically cleaned with the help of coarse and
fine rakes as well as a screening belt. In
this way, around 75 tons of dirt and waste
are removed from the Rhine river every
year.
Combined cycle power plantThe combined cycle power plant unit 4
allows EnBW to achieve an excellent effi-
ciency level of around 57% using natural
gas as a fuel; this spares natural resources
and takes the strain off the environment –
by reducing CO2 emissions, for example.
In addition, state-of-the-art combustion
technology reduces the formation of ni-
trogen oxides.
Steam turbine in unit 7 in Rheinhafen
26
CogenerationUnit 7 operates according to the cogenera-
tion principle. Heat is extracted at the tur-
bine in the form of hot steam and forwarded
via heat exchangers to the hot water sys -
tem of the Stadtwerke Karlsruhe GmbH
utility, supplying district heat to around
23,000 private households and over 1,300
industrial and commercial customers.
The extraction of district heat raises the
utilisation rate of unit 7. This not only
spares valuable energy resources but also
has a positive impact on the air quality in
the city of Karlsruhe: this is not surprising,
as the central district heat supply system
replaces a high number of decentral in-
dividual heating systems with relatively
high pollutant emissions.
27
Technical data
Year built: 1955 Units: 1 combination unit
1 coal unit2 oil- and gas-fired units in cold reserve
Gross electrical rating: 1,208 MWelExtractable district heat output: 220 MWth
Combination unit 4 in
Rheinhafen
Innovative new facility
Unit 8 in Rheinhafen is being built to the
east of the existing facilities and is sche-
duled for completion in 2012.
The innovative technology of the new coal-
fired unit will increase efficiency levels
and reduce specific CO2 emissions by 30%
compared to the current global average.
This EnBW investment helps to boost
energy efficiency. The extremely high effi-
ciency level is due to the high steam para-
meters at the steam turbine inlet, the low
condenser pressure and the high internal
efficiency levels of steam turbine, genera-
tor and transformer. The fact that up to
220 MW of district heat can be extracted
from unit 8 will additionally increase the
utilisation rate.
The construction site comes to life in the early morning hours
28
Technologies that spare the environment
Numerous innovative new features have
been incorporated in the new power plant
in order to ensure even more effective
protection of the environment:
› A modern firing concept reduces nitro-gen oxide formation and the amount of
excess air during combustion – and there -
fore also increases the efficiency of the
boiler.
› The use of a new blade concept booststhe internal efficiency of the turbine.
› A so-called wet stack without flue gas reheating increases the efficiency of the
overall plant.
› In addition, unit 8 in Rheinhafen has sufficient space for the subsequent re -
trofitting of a CO2 capture system.
The CO2 capture concept is currently not
feasible on a large scale. EnBW is involved
in the development of new capture tech -
niques and is working on potential solu -
tions together with various universities.
29
Technical data
Start-up: 2012Units: 1 coal unitGross electrical rating: 912 MWelExtractable district heat output: 220 MWth
View of the construction site for unit 8 in Rheinhafen
Location
The Bexbach coal-fired power plant is
located in the Saarland region close to a
former coalmine and has the biggest out-
put of any unit-type power plant in the
Saarland.
History
The Barbara I power plant was built at this
location back in 1953 and was fired using
low-grade coal from the Bexbach mine. A
further power plant, Barbara II, went into
operation in 1960, and 1979 saw the start
of building work on the current power
plant unit, which went on stream in 1983
after a four-year construction period.
The power plant is jointly owned by EnBW
Kraftwerke AG and Evonik Power Saar
GmbH. EnBW has a 100% electricity sup-
ply entitlement in Bexbach, while Evonik
Power Saar GmbH has been responsible
for operation of the power plant since it
first started up.
Holdings and electricity procurementBexbach power plant
The Bexbach power plant is the biggest unit-type plant in the Saarland region
30
Technical data
Year built: 1953Units: 1 coal blockGross electrical rating: 750 MWel
Location
The Lippendorf power plant is around 15
kilometres to the south of Leipzig. The two
lignite units "S" and "R" went into opera -
tion in 1999. Unit R is owned by the opera-
tor of the power plant, Vattenfall Europe
Generation AG, while unit S belongs to
EnBW Kraftwerke AG. The power plant also
supplies district heat to the city of Leipzig.
History
As far back as 1926, an industrial power
plant was already operating at the Lippen-
dorf location and supplied electricity to
the Böhlen chemical factory. A further
power plant was added in the 1960s to gen-
erate power for the chemical company
and to act as a baseload supply plant for
the southern region of the former East
Germany. When new environmental legis-
lation came into effect in 1990, the owners
decided that it would not be feasible to re-
trofit modern environmental technology
and drew up plans to build an optimised
lignite-fired double-unit plant. After the
new plant went on line, the old power
plants were closed down and decommis-
sioned step by step. The two units have a
gross installed capacity of 920 MW each.
When they went into operation, they were
considered the biggest and most efficient
lignite power plant units worldwide. The
facility has a net efficiency of around 42%;
the extraction of district heat boosts the
fuel utilisation rate to 46%. The Lippen-
dorf plant has been co-combusting sewage
sludge since 2004.
31
Lippendorf power plant
The Lippendorf power plant not only generates electricity but also supplies the
city of Leipzig with district heat
Technical data
Year built: 1999Units: 2 coal unitsGross electrical rating: 1,840 MWel
Location
The Rostock power plant is located in Ros -
tock's sea port. The coal-fired power plant
went into operation in September 1994.
On January 1, 2010, EnBW acquired a 100%
stake in Gesellschaft für die Beteiligung
an dem Kraftwerk Rostock mbH, which
in turn holds a 50.4 percent share in the
Rostock power plant. The other share-
holders are Vattenfall Europe (25%) and
RWE Power (24.6%).
History
Construction work on the power plant be-
gan in June 1991, and the facility was mod -
ernised to meet the requirements of the
liberalised electricity market in 1998. The
coal-fired power plant has a gross capacity
of 553 MWel and feeds 150 MWth of heat -
ing energy into Rostock's district heating
network. It therefore currently produces
more than half of all electric energy gen -
erated in the state of Mecklenburg-West
Pomerania and covers around one third of
electricity demand in the entire state as
well as 20% of the district heat require-
ments in the city of Rostock.
The power plant has an efficiency level of
43.2%, and full utilisation of heat extracti-
on increases the utilisation rate to as high
as 62%. One of the special features of the
power plant is the 141.5 metre-high cool -
ing tower that uses seawater and also acts
as a chimney stack.
Rostock power plant
The power plant is located in the sea port in Rostock
32
Technical data
Year built: 1994Units: 1 coal unitGross electrical rating: 553 MWelExtractable district heat output: 150 MWth
33
Buschhaus power plant
Location
The Buschhaus power plant is around
eight kilometres from the town of Helm-
stedt. The lignite plant went into opera -
tion in 1985 and was modernised in 2002.
It is operated by E.ON Kraftwerke GmbH,
and 45.2% of the energy generated by the
plant (159 MW) is supplied directly to
EnBW Kraftwerke AG.
History
Helmstedt is a lignite mining town and
has been generating electricity since 1906.
All in all, nine power plants have been
commissioned since then, the Buschhaus
facility being the most recent addition.
The baseload power plant is specially de -
signed to incinerate the sulphurous high-
salt lignite from the Schöningen open-cast
mine.
The plant always keeps temperatures to
below 1,100 degrees Celsius during the
combustion process to minimise the for-
mation of nitrogen oxides, thus rendering
a denitrification system unnecessary. The
special feature of the Buschhaus plant is
its stack: at a height of 307 metres, it is the
highest stack anywhere in Germany and is
easily visible from afar.
Specialist for high-salt lignite – the Buschhaus power plant
Technical data
Year built: 1906Units: 1 coal unitGross electrical rating: 392 MWel
34
Location
Stadtwerke Düsseldorf (SWD) is a munici-
pal utility in which EnBW holds a majority
stake. SWD operates a network of different
types of generating facilities, including
fossil-fuelled power plants like those at
the "Lausward" and "Flingern" locations.
History
The first municipal gasworks went on line
back in 1866. Today, there are two units
operating at the "Lausward" location in
Düsseldorf's port district: a gas and steam
plant with a capacity of 103 MWel and 75
MWth completed in 2003. This facility is
particularly efficient and has an efficiency
rating of up to 87%. The unit with the high -
est output is the natural gas-fired "Emil"
combination unit dating back to 1972 with
capacities of 420 MWel and 140 MWth.
With its combination of gas turbine and
steam boiler, "Emil" is a mixture of a gas
and steam plant and a heat and power
plant. In the city district of Flingern, the
steam from the waste incineration plant
generates up to 55 MW of electricity and
100 MW of district heat. Two peak-load
boilers, each with a capacity of 50 MWth,
serve as back up systems. A gas turbine
has also been in operation at this location
since 1973, and this turbine acts as a kind
of emergency power assembly: its six
aircraft turbines can produce 90 MW of
electricity within the space of just a few
minutes.
Stadtwerke Düsseldorf municipal utility
The "Lausward" plant is at the heart of the city and generates energy for Düsseldorf and
the surrounding region
Technical data
Year built: 1866Units: 1 combination unit
1 gas and steam unit1 waste incineration system
Gross electrical rating: 668 MWelExtractable district heat output: 315 MWth
35
Grosskraftwerk Mannheim power plant
Location
Grosskraftwerk Mannheim AG (GKM)
operates one of the most efficient coal-
fired power plants in Europe. Located di-
rectly on the Rhine, it is ideally situated
to ensure generation and feed-in of power
close to the points of consumption. The
GKM power plant is jointly owned by RWE
Power AG (40%), EnBW Kraftwerke AG
(32%) and MVV RHE GmbH (28 %).
History
The Mannheim power plant was set up in
1921 by the Pfalzwerke der Stadt Mann-
heim utility, the Badische Landeselektrizi-
tätsversorgung company (later Badenwerk
and today EnBW) and the Neckar AG cor-
poration. The first boilers went into opera-
tion in 1923. For around 90 years now,
GKM has reliably been producing electrici-
ty and district heat for Mannheim and the
Rhine-Neckar metropolitan region. The
plant consists of the coal-fired units 3, 4, 6,
7 and 8 with an aggregate net capacity of
1,520 MW of electricity and around 1,000
MW of extracted district heat. One of the
special characteristics of the Mannheim
facility is that 190 MW of the net capacity
are rerouted to supply a power line of the
Deutsche Bahn rail company. As part of
the modernisation programme for the
power plant fleet, GKM is building a new
coal-fired unit on the eastern section of its
operating site: unit 9 is scheduled to go on
stream at the end of 2013 with an output
of 911 MW and will replace units 3 and 4.
The power plant supplies electricity and heat to the city of Mannheim and the
Rhine-Neckar region
Technical data
Year built: 1921Units: 5 coal unitsGross electrical rating: 1,675 MWelExtractable district heat output: 1,000 MWth
The technology of a power plant
The power plant process
A coal-fired power plant converts thermal
energy into electric energy with the help
of steam – which is why it is also called a
steam power plant.
The combustion of coal produces hot flue
gases which are used to generate steam.
The steam flows through a turbine and
passes on its energy to the turbine blades.
This energy is converted into rotational
energy. The turbine shaft drives a genera-
tor which generates electricity. The spent
steam is cooled in the condenser to create
water, which is then pumped back into the
steam generator. In this way, thermal and
mechanical energy are used to convert
chemically bound energy into the desired
electric energy.
Technology made easyHow fossil-fired power plants work
Emission monitoring
Desulphurisation Dedusting Denitrification Steam generator
Transformer
Burner Coal mill
Steam turbine
Condenser
Generator
River
Feed water pump
Cooling water cleaning
Induced draught fan
38
How a fossil-fired power plant works
Combined cycle plant
In a gas and steam turbine power plant,
the energy generation function of the gas
turbine is combined with the steam power
process. The hot flue gases from the gas
turbine are not discharged into the atmos -
phere unused but forwarded to a heat
recovery steam generator to generate
steam which is used in the steam turbine.
The combina tion of these two processes
increases the efficiency of the plant.
39
River
Steam turbine
Condenser
Flue gas Fresh airSound absorber
Compressor
Generator
Generator
Feed water pump
Reheater
Heat recoverysteam generator
Transformers
Switchgear
TurbineFuel
How a combined cycle plant works
Cogeneration
As a rule, power plants generate electricity
by burning fossil fuels. Plants that pro duce
not only electricity but also heat (e.g. district
heat) on the other hand, operate on the co-
generation principle and are also called
combined heat and power plants. The heat
is extracted from the turbine in the form of
hot steam. It is then forwarded via heat ex-
changers to a distribution system that sup-
plies the heat to private households (heat-
ing energy) and industrial companies (pro-
cess heat). The simultaneous genera tion of
electricity and heat exploits the primary
energy of the fuel more effectively and
there fore significantly improves the fuel
utilisation rate of cogeneration plants. Pol-
lutant emissions are also reduced, as central
district heat supplies from the heat and
power plant replace a high number of de-
central individual heating systems.
40
Emission monitoring
Desulphurisation Dedusting Denitrification Steam generator
Transformer
Coal mill Steam turbine Condenser Generator
Cooling tower
District heat extraction
Cooling water cleaning
Fans
Induced draught fan
District heat extraction – the example of unit 8 in Rheinhafen
Steam turbine
The guide blades of the steam turbine di-
rect the steam towards the rotor blades at
an optimum angle, and the rotor blades
then set the turbine shaft in motion. The
pressure of the steam falls as it passes
through the blades while the volume of
the steam increases. This is why the blades
are always longer towards the end of the
turbine.
41
Rotor blades
Guide blades
Live steam
Turbine shaft
Steam outlet to reheater
Sectional view of a high-pressure turbine
Gas turbine
Gas turbines can work to full capacity with -
in the space of just a few minutes: large
volumes of intake air are compressed in
the compressor and flow into the com -
bustion chamber of the gas turbine, where
natural gas is incinerated together with
the compressed air. The hot flue gas then
flows onto the turbine at high tempera -
ture and drives the turbine.
Fresh airGenerator
Combustion chamber
Flue gas
Turbine
Fuel feed
Compressor
42
Sectional view of a gas turbine
Cooling process
There are three main techniques used for
cooling in modern power plants: once-
through cooling, discharge cooling and circuit
cooling. In all three methods, the steam flows
from the low-pressure turbine to the conden-
ser, which houses a tubular system through
which the cooling water flows. The incoming
steam condenses to water on the outside of
the tubes and gives off its evaporation heat to
the cooling water. The condensate is then
pumped back into the boiler, which once
again generates steam.
In once-through cooling systems, the cool -
ing water is extracted from the so-called re-
ceiving water course (river, lake, ocean) and
discharged directly back into the receiving
water course after the steam has been cool -
ed in the condenser. In discharge cooling,
the cooling water is cooled in a cooling
tower by giving off its heat to the ambient
air before being routed back into the re-
ceiving water course. In circuit cooling, the
cooling water constantly circulates between
cooling tower and condenser. Water is only
fed into the circuit to replace the cooling
water loss, which is generally visible in the
form of the steam plume above the tower.
There are also different types of cooling
tower. A tall tower is a sign of a natural
draught wet cooling tower, in which the
cooling water is finely drizzled. The air ris -
ing in the tower reduces the temperature of
the cooling water. The high tower creates a
natural draught that causes the air to flow
43
Wetted surface
Fans
Cooling water basin
PumpHeat exchanger
Hybrid cooling tower
Condenser
Condensate at 39°C to feed water tank
Outlet steamfrom turbineapprox. 35°C - 40°C0.07 bar
through the cooling tower. The mechanical-
draft cooling towers operate on the same
principle but do not need to be anywhere
near as high – but they do need fans to ensure
sufficient air flows and this increases the au-
xiliary consumption of the power plant.
The hybrid cooling tower is a special kind of
tower which combines wet cooling and dry
cooling techniques. This combination almost
totally eliminates plume formation. This type
of tower also uses fans to generate the cool -
ing air flow. This means that hybrid cool -
ing towers do not have to be particularly high,
and they therefore blend in with the surround -
ing area around a power plant. Only five hy-
brid cooling towers are currently in operation
worldwide, and three of them are part of the
EnBW power plant fleet.
Cooling at the combined heat and power plant 2 (CHP 2) at the Altbach/Deizisau location
Denitrification
The denitrification system uses the so-
called selective catalytic reduction method:
ammonia is sprayed into the hot flue gas
and the mixture is then routed via cata-
lysts in which a chemical reac tion takes
place. During this process, over 70% of the
nitrogen oxides are converted into harm-
less nitrogen (N2) and water (H2O).
Flue gas containing nitrogen
Ammonia (NH3)
Catalysts
Nitrogen (N2)
Water (H2O)
Flue gas with nitrogen concentration 100 mg/Nm3
44
Dedusting
During the dedusting process, the fly ash
is removed from the flue gas. This process
takes place in large electrostatic precipita-
tors, where discharge electrodes create a
strong electric field. The ash particles are
negatively charged and settle on the posi-
tively charged separator plates before
being removed by beater mechanisms.
This process removes more than 99.9%
of the fly ash from the flue gas.
Discharge electrode
Collector plate
Beater mechanism
Ash hopper
Fly ash
++ ++ ++ ++__
99.9% dedusted flue gas
Flue gas with fly ash
Voltage between the electrodes:40,000 to 60,000 volts
__
Denitrification and dedusting in the power plant process
45
Desulphurisation
In the desulphurisation process, the waste
gas containing sulphur dioxide flows up-
wards in a scrubber and is sprayed with a
suspension of limestone and water. The
SO2 binds and is then captured in the ab-
sorber sump. The injected air causes the
calcium sulphite – the reaction product of
sulphur dioxide, limestone and water – to
oxidise to form calcium sulphate (gyp-
sum). In the wet scrubbing process, the
capture rate for sulphur dioxide is in ex-
cess of 90%.
Stack
Flue gas
Limestone powder
Limestone silo
Limestone suspension tank Oxidation air Absorber
Process water
Hydrocyclone
Gypsum silo
Gypsum for reutilisation
Filtrate to absorber
Belt filter
Clean gas
Desulphurisation in the power plant process
The electricity grid of EnBW is made up of
the transmission network and the various
distribution networks. EnBW Transport-
netze AG (TNG) operates the transmission
network in Baden-Württemberg. This net-
work comprises around 3,650 kilometres
of 380 and 220 kilovolt (kv) very high-vol-
tage lines which are connected to the re-
gional 110 kv distribution networks of the
various companies via 81 transformers.
The biggest 110 kV network is operated by
EnBW Regional AG (REG). The TNG trans-
mission network is ideally integrated in
the German and European interconnec -
tion system via 36 coupling points. It is
directly connected to the transmission
networks within Germany as well as those
crossing over into France, Austria and
Switzerland.
In line with the German Energy Industry
Act, the job of TNG is to provide all market
participants with access to the transmis -
sion network at transparent and non-dis -
criminatory conditions and to ensure the
reliable supply of electricity at all times.
To this end, we continuously monitor and
control the energy flows in the network,
performing maintenance work and expand -
ing the network as and when necessary.
With the aim of ensuring a balance bet-
ween generation and consumption in the
electricity supply system in Baden-Würt-
temberg at all times and controlling the
exchange of electricity with other coun-
tries, TNG is responsible for planning and
implementing the following measures:
› Regulation of the power frequency, in other words, using balancing energy to
ensure a stable frequency of 50 Hertz
throughout Europe
› Schedule management – the coordinationof the import, export and power plant
schedules of the electricity traders and
power plant companies in the TNG con-
trol area
› Marketing the forecast and actual feed-inof energy volumes from renewables on
the electricity exchange
The EEG legislation that gives precedence
to renewable sources of energy has extend -
ed the remit of the German transmission
system operators. As a result – and due to
the central location of the TNG control
area – TNG has to transport wind energy
feed-in in the north to the core consump-
tion areas in the south.
Stable and flexibleThe electricity network of EnBW
46
Environmental protection measures
In the construction and operation of its
electricity networks, EnBW attaches major
importance to minimising the impact on
existing ecosystems: cableways are laid to-
gether, maintenance routines are based on
ecological considerations and planning
concepts take account of breeding seasons
and vegetation periods.
EnBW has long played a pioneering role in
Germany when it comes to bird protection
in the medium-voltage network. At the
end of the 1990s, work began on nume-
rous programmes to make overhead cables
safer in coordination with the Baden-
Württemberg Environmental Affairs Min -
istry: based on the catalogue of measures
laid out by the German Association of
Energy and Water Industries in consultation
with nature conservation associations,
for example, most of the 20-kV overhead
line network has been equipped with pro-
tective hoods, perches and deterrents to
make the system safe for birds.
In 2007, EnBW initiated a study to explore
the hazard potential of high and very-high
voltage lines. The findings formed the
basis for the identification and implemen-
tation of a number of effective bird protec -
tion measures. The high safety standard is
underpinned by constant checks and ser-
vicing measures.
47
Combination plant, combination unit –power plant in which the gas turbine and
steam power process are combined. Either
the flue gases from the gas turbine are used
as combustion air in a steam generator, or
steam is generated directly in a heat exchanger
(gas and steam turbine plant).
Combination unit –� combination of gas tur-bine heat recovery steam generator system
and steam power plant. The steam generated
in the heat recovery steam generator using
the gas heat is fed into the steam cycle of the
steam power plant. The advantage of a com-
bination unit is that steam power plant and
gas turbine can also be operated indepen-
dently of one another.
Demand peak – peak load
Efficiency – ratio of produced output to re-source input – in the case of a machine, for
example, the ratio of energy output to ener-
gy input. Only a part of the energy is con -
verted into a new usable form of energy; the
remainder is converted into a form of energy
that cannot be used at all or is difficult to use.
An electric motor, for example, transforms
the input energy not only into useable kine-
tic energy but also to a lesser degree into
Baseload – the basic demand for electricitythat exists irrespective of all load fluctua -
tions. Baseload is covered by power plants
that can operate around the clock more or
less throughout the entire year.
Black start – start-up of a power plant unitwithout electricity from the electricity net-
work. Black start capable units are used to
build up the electricity network again after
a black out.
Carbon capture and storage (CCS) – capture and geological storage of the green-
house gas CO2 occurring in industrial and
power plant processes.
Clean Development Mechanism (CDM) – an instrument under the Kyoto Protocol de -
signed to limit the growth-related increase
in greenhouse emissions in economies in
transition and developing countries through
the implementation of cost-effective and effi -
cient measures. The achieved emission re-
ductions are credited to the investor in the
form of certified emission reductions (CERs).
Companies can use CERs to meet their sur-
render obligation in line with the European
allowance trading scheme (emissions trad -
ing).
Cogeneration – the simultaneous generationof electricity and heat based on the cogen -
eration principle ensures the best possible
utilisation of the energy contained in the
fuel. The heat from a power plant can be
used in the vicinity to heat buildings or as
process heat in industry. A power plant that
produces both electricity and heat is called
a combined heat and power plant.
Cold reserve – a power plant that is not tobe used for an indefinite period of time but
operated once again at a later date is "con-
served" and placed in cold reserve. It gener-
ally then takes a few months to prepare the
unit to return to fully-fledged operation.
Combined heat and power plant (CHPplant) �– energy conversion plant that simul-taneously generates electricity and useful
heat (cogeneration). Big power plants are
operated on an electricity-led basis (in other
words, district heat or process steam is de-
coupled). Smaller combined heat and power
plants tend to be heat-led – in other words,
they are operated in response to heat con-
sumption and electricity is a desirable by-
product. Heat-led combined heat and power
plants have utilisation rates of over 70%.
Glossary
48
non-usable thermal energy. Due to the laws
of thermodynamics, the efficiency of a sys -
tem is always lower than 1, even in ideal con-
ditions.
Electric output – installed capacity
Emission allowance trading – trading withemission certificates is an environmental pol-
icy instrument and is designed to promote
climate protection. In the Kyoto Protocol,
the industrialised nations agreed to reduce
worldwide greenhouse gas emissions. In or-
der to maximise the efficiency with which
the reduction quota for greenhouse gases is
divided up, the admissible emission volume
of each country is split into so-called emis -
sion certificates that permit the emission of
specific volumes of greenhouse gases. These
emission allowances can be traded between
countries. In order to achieve its emission
reduction targets, the European Union has
introduced an allowance trading scheme on
company level. European Union allowances
(EUAs) are issued to the participating com -
panies based on National Allocation Plans
(NAPs). Companies who need more allowance
units than they have been allocated have to
purchase additional units. Companies who
receive more units than they need can sell
49
them. Each market participant is free to
decide whether to buy allowance units or
implement modernisation measures.
Flue gas cleaning – extensive reduction inthe volume of flue gas components like ni-
trogen oxides, dust and sulphur dioxide oc-
curring during the combustion of solid fuels
like coal. In this process, the flue gases from
the boiler pass through separate cleaning
stages.
Flue gas desulphurisation system – serves
to reduce the concentration of sulphur di-
oxide in the flue gas flow. The most common
technique is to spray the flue gases with a
limestone suspension in a wet scrubbing
process. During the scrubbing stage using
the absorption solution, the sulphur oxides
in the flue gas bind with the limestone to
form calcium sulphite, which then oxidises
to form gypsum in the scrubber sump
follow ing the injection of air.
Flue gas scrubbing system – flue gas scrub-
bing reduces the concentration in the gas of
pollutants resulting from waste incineration.
The system consists of a wet scrubber. The
pollutants – HCI (hydrochloric acid), SO2(sulphur dioxide), HF (hydrogen fluoride),
heavy metals, dioxins and furans as well as
dust – are washed out and removed at the end
of the process in the form of dry salts.
Gas and steam turbine plant – in a combinedgas turbine and steam power process, the
thermal energy of the extremely hot gases
from the gas turbine is not discharged into
the atmosphere unused but transferred via a
heat exchanger to a steam power process
which makes use of this energy. This makes
it possible to combine the advantages of
both processes: the high inlet temperature
of the combustion gases into the gas turbine
and the lower temperature of the steam at
the end of the water-steam cycle. Utilisation
of this high temperature differ ential greatly
improves the efficiency level.
Gas turbine – a gas turbine essentially con-sists of a compressor, a combustion chamber
and a turbine. Air is taken in from the sur-
rounding atmosphere via the compressor
and compressed. The compressed air is
routed into the combustion chamber of the
gas turbine, where it reacts with the feed fuel.
In the turbine section of the gas turbine – like
in a steam turbine – the gases are then flashed
to ambient pressure. The flashed combustion
gases are then discharged through a stack
Primary energy – the energy stored in natu-ral energy sources like coal, crude oil or natu-
ral gas.
Reactive power – reactive power is the elec-trical output needed to create magnetised
fields (in motors or transformers, for exam-
ple) or electrical fields (e.g. in condensers)
and that does not contribute to "useful
work".
Repowering – repowering is when old powerplants are replaced by new, modern, general-
ly more efficient plants. Power plants are on-
ly designed for a certain service life. To allow
operation after this time, the core compo-
nents have to be replaced with modern com-
ponents that are in line with the state of the
art. Repowering also provides an opportuni-
ty to change the type of power plant. When a
power plant is repowered, it generally con -
tinues to use the existing infrastructure.
Reserve capacity – this secures the opera -tion of the interconnection grid even in the
event of the unexpected failure of large-scale
generating units.
Retrofit – a term used to describe the moder-nisation of existing power plants. One of the
either directly or via a heat exchanger which
utilises the heat of the waste gases.
Gas turbine process – cyclical process, thepurpose of which is to produce work using air
as the working medium. The thermodynamic
comparison process is the so-called hot air or
Joule process.
Generating reserve – reserve capacity
Interconnection grid – the totality of all syn-chronously interconnected transmission net-
works.
Intermediate load – level of increased electri-city demand. This is where there are regular
fluctuations of the load curve above the base-
load – in times of increased electricity con-
sumption in the morning, at midday and in
the evening, for example.
kV – kilovolt; 1 kilovolt = 1,000 volts
Minute reserve – this output reserve is need -ed if additional output has to be fed into the
network in order to prevent the network fre-
quency dropping below 50 Hertz. This reserve
is supplied by storage, pumped-storage and
gas turbine power plants.
MW – megawatt; 1 megawatt = 1,000 kilo-
watts = 1,000,000 watts. This unit of output
measurement is used for large-scale electri-
cal facilities.
Peak load – the level of highest electricitydemand. This short-term peak load on the
electricity network is generally foreseeable
based on long experience and is mainly
covered with the help of storage, pumped-
storage and gas turbine power plants. The
machines in these power plants can operate
at full power inside a matter of minutes.
Power output – the product of current andvoltage or work per unit of time. Power out-
put is expressed in watts or joules per sec -
ond. In the area of power plants, the power
output is measured in megawatts (MW).
Power plant by-products – by-products likefly ash, boiler ash and gypsum occur in the
power plant industry and are used as second -
ary raw materials in the building sector. The
energy industry believes these by-products
fully meet the requirements for by-products
under the Waste Framework Directive and
are therefore subject to the REACH legislati-
on, an EU regulation that came into effect on
June 1, 2007. REACH stands for registration,
evaluation and authorisation of chemicals.
50
main reasons individual power plant compo-
nents are modernised is to increase their effi-
ciency. Retrofit measures also pave the way
for the generation of "green megawatts": this
means that a technically optimised facility is
able to generate a higher volume of electricity
from the same fuel input.
Safety reserve – minute reserve
Sewage sludge co-combustion – mechani-cally dewatered and thermally dried sewage
sludge can be incinerated together with coal.
The precondition is that the sewage sludge
complies with the waste sewage sludge regu-
lations. This waste from sewage plants pro -
duced by humans used to be mainly disposed
of in landfill sites or used in agriculture and
within the framework of recultivation meas -
ures at exhausted lignite sites. Since June 1,
2005, however, the "German Technical Regula -
tions on Municipal Waste" have prohibited
the disposal of sewage sludge at landfill sites
for household waste. This makes thermal utili -
sation in power plants a technically feasible
and environmentally sparing disposal option.
The high combustion temperatures ensure
that the organic pollutants, in particular the
halogenides, are completely destroyed; the
residual moisture in the sewage sludge eva -
51
porates. In-depth investigations by certified
laboratories have confirmed that, up to a
certain volume, the co-incineration of sewage
sludge has no effect whatsoever on the quality
of the clean gas and residual substances result -
ing from operation of the power plant.
Steam power process – thermodynamic cyclical process designed to produce work.
Water and steam are used as working media.
All steam power processes are based on the
so-called Clausius Rankine process.
Thermal capacity – in physics, the thermalcapacity is a parameter of an energy conver -
sion installation that generates heat. It is nor-
mally measured in watts or joules per second.
In steam power plants, this is the energy con-
tained in the steam generated by the steam
generator based on steam volume, steam
temperature and steam pressure. In a steam
generator, the thermal capacity corresponds
to the heat content of the fuel used (thermal
fir ing capacity) minus the losses due to waste
gases and any other heat transfer from the
plant to the environment.
Once-through cooling – in once-throughcooling, water is taken from a river, mechani-
cally cleaned and routed through the cooling
tubes of the condenser. The steam flowing
out of the turbine into the condenser gives
off its evaporation heat to the cooling water,
which is then discharged back into the river.
Utilisation rate – a measure of how much ofthe energy stored in the energy source is ac-
tually utilised as usable energy. In the case of
systems generating electricity in cogenera -
tion mode, the utilisation rate describes the
ratio of total utilised energy output (electri-
city and heat output together) to the energy
input (primary energy). The difference bet-
ween the utilisation rate and efficiency is
that the latter only takes account of pure
electricity generation.
Waste incineration plant – the purpose ofwaste incineration plants is to dispose of
waste while using the energy it contains to
generate (for example) electricity and heat.
This also reduces the volume of waste that
needs to be stored in landfills. Since June 1,
2005 the "Technical Regulations on House-
hold Waste" have prohibited the disposal of
household waste unless it has been pro -
cessed. Thermal processing of waste in waste
incineration plants is therefore also used to
pre-treat household and industrial waste
prior to landfill storage.
EnBW Info CentresCentral Visitor ManagementPhone: 0800 2030040
E-mail: besichtigungen@enbw.com
Power plant locationsAltbach/Deizisau heat and power plantIndustriestraße 11
73776 Altbach
Rheinhafen steam power plant in KarlsruheFettweisstraße 44
76189 Karlsruhe
Münster residual waste heat and power plantVoltastraße 45
70376 Stuttgart
Grosskraftwerk Mannheim power plantThe Grosskraftwerk Mannheim
Aktiengesellschaft (GKM) company in
Mannheim-Neckarau opened an informa-
tion centre for interested visitors at the
end of 2010. The centre provides informa-
tion on the GKM itself as well as on the
new "Unit 9" construction project. You can
find more details at www.gkm.de.
Plant tours
52
PublisherEnBW Energie Baden-Württemberg AG
Durlacher Allee 93
76131 Karlsruhe
Internet: www.enbw.com
Responsible for corporate publicationsCorporate Communications,
Karlsruhe
Layout and designCorporate Competence Centre Marketing,
Stuttgart
PhotosArtis Foto, Karlsruhe
Volker Dautzenberg, München
Daniel Döbler, Poppenweiler
TranslationAnthony Tranter-Krstev, Germersheim
LithographyRepro 2000, Leonberg
Printed bySommer Corporate Media, Waiblingen
ISBA: B.2567.1012
Published in December 2010
Publishing details
EnBW EnergieBaden-Württemberg AG
Durlacher Allee 9376131 KarlsruhePhone +49 (0)721 63-06Fax +49 (0)721 63-12725info@enbw.comwww.enbw.com
top related