EFFICIENCY AND CAPTURE-READINESS
OF NEW FOSSIL POWER PLANTS IN THE EU
Wina Graus
Mauro Roglieri
Piotr Jaworski
Luca Alberio
Ecofys Netherlands bv, Utrecht
July 2008
Project number: PECSNL074210
Assignment for: European Commission (subcontracted to MVV under Framework Contract N° TREN/CC/05-2005)
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JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Executive summary
In this study we focus on energy-efficiency and capture-readiness of recently built (>1997)
and planned fossil-fired power plants. The study has two main purposes:
(1) To evaluate energy-efficiency of new1 fossil power plants and compare them with
the energy-efficiency that would be expected when using best available techniques
(BAT).
(2) To see what share of new power plants can be considered as capture-ready.
For this purpose we first look at the energy-efficiency that would be expected to be
achieved by applying BAT and we define requirements for capture-readiness. In the second step we analyse the new power plants with respect to these two characteristics, i.e
energy efficiency and carbon capture readiness.
Energy-efficiency by applying best available techniques
Below is the net energy-efficiency that was found in this study for applying best available
techniques per type of power plant.
Table 1 Energy-efficiency by appl ying best available techniques in 2008
Technology
Pulverised
coal
steam
cycle
(ultra-
supercritical)
2
Fuel
Net energyefficiency
Coal
46%
Lignite
43%
Coal gasification combined cycle (IGCC )
Coal
Natural gas combined cycle (NGCC)
Natural gas
46%
59-60%
Local circumstances influence the maximum efficiency that can be achieved in a power
plant. The most important factors, found in this study, that influence design energyefficiency are the type of cooling method used and the temperature of the cooling water.
This can influence energy-efficiency by up to 3 percent points. Year round operational efficiency can be 1-7 percent point lower than design energy-efficiency and largely depends
on the amount of load hours.
1
Recently built (>1997) and planned power plants together are in this study also referred to as
“new plants”.
2
IGCC can also operate with oil or biomass, but in this study we focus specifically on coal (ICGCC).
Requirements for capture-readiness
Capture-ready means that a plant can be equipped with CO2 capture technology while it is
under construction or after it is built. If a plant is not capture-ready this means it is either
more expensive to add CO2 capture technology or impossible due to insufficient space at
the site or no suitable reservoir to store the CO2 in. This means that it is important for new
fossil plants to be capture-ready in order to have the possibility to add CO2 capture and
storage at a later stage.
In order for a power plant to be capture-ready the following requirements should be met|:
• A study on the possible options for CCS in terms of technology and feasibility
•
should be done.
An assessment should be made of the elements of the plant that would need to be
adapted when adding CO2 capture equipment, their place in the plant layout and
their physical size.
•
An assessment of the possible pre-investments that can be done in comparison to
the costs of making changes when the power plant is built.
•
The availability of sufficient space for the required CCS technology during operation as well as during construction. At the same time normal operation of the exist-
•
ing plant has to be assured both during construction and operation of CCS.
An assessment of a storage site and a credible route to the storage site is needed.
Capture-ready plants are somewhat more expensive to build. The costs consist mainly of
the purchase of additional land area.
Plant selection
In this study we look specifically at large-scale gas and coal-fired plants, with units bigger
than 300 MW. This includes roughly 260 new power plants in the EU owned by 130 utilities. The capacity of these plants together equals nearly 200 GW, equivalent to 25% of total operational capacity in the EU. Table 2 gives the amount of recently built and planned
coal and gas-fired power plants in the EU.
Ta ble 2 Total re cently built and pl anned coal and gas pow er pl ants (wi th uni ts
bigger than 300 MW)
Pulverised coal
Pulverised
– hard coal
coal - lignite
IGCC
NGCC
Total
Operational > 1997
2
6
0
42
51
Under construction
4
4
0
18
26
Planned
31
3
0
65
99
Early stage of planning
16
2
4
66
88
Total
54
15
4
191
263
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
The largest share of new plants consists of gas-fired plants (75%). In terms of capacity,
coal-fired power plants account for 33% in total capacity with 65 GW.
In terms of countries, Spain has the highest number of new plants (49 gas-fired and 1 coalfired plant), followed by Germany (30 coal-fired and 12 gas-fired plants) and Italy (29 gasfired and 6 coal-fired plants).
Data gathering
Since no literature sources were available for this study, with data on efficiency and capture-readiness on a plant level, we sent questionnaires to utilities asking for information on
plant level. Additionally, telephone interviews were held with several utilities and power
plant suppliers. In total, we received questionnaires for 68 power plants, consisting of 16
coal-fired and 52 gas-fired plants. Together the plants represent 25% of total new capacity
(with units > 300 MW). It is unsure if the results found for these plants are representative
for the other installed capacity. However, based on the interviews with utilities and power
plant suppliers, and based on a number of public data sources, we think the results give
quite a good picture of the situation in the EU.
Results and conclusions
The results show that most of the power plants for which information was submitted in the
questionnaires, have energy-efficiencies close to BAT level. The average net energyefficiency, for planned coal-fired power plants was 46% and for planned gas-fired plants
58%.
Utilities and suppliers mention in the telephone interviews that energy-efficiency is one of
the key aspects that influence the economics of a power plant. High energy and CO2
prices can therefore give a further incentive for the use and development of efficient technologies.
Regarding capture-readiness, the results of the study indicate that most of the recently
built power plants are not capture-ready. Of the planned coal-fired power plants, a large
share is expected to be capture-ready (13 out of 16). For the planned gas-fired power
plants only 2 out of 31 are expected to be capture-ready. Since gas-fired power plants account for two third of new fossil capacity it would be desirable that a significant share of
gas-fired power plants are capture-ready, in order to be able to use CCS for deep CO2
emission reduction targets in the power sector. In order to make CCS an option for gasfired plants, additional research is needed to solve a few technological issues. Additionally,
financial incentives may be needed to compensate for the higher capture price per tonne of
CO2 in comparison to coal-fired plants.
During the telephone interviews utilities and suppliers mention that there is a need for a
clear and long-term regulatory framework for CCS. In order for CCS to be implemented,
CO2 prices need to be at least 40-50 €/ton. Furthermore, the EU could play a role in harmonizing the set up of national infrastructures for CO2 transport. E.g. by setting rules for
transport of CO2 across boundaries. And lastly, there is a strong need for plants on dem-
onstration scale. This requires financial incentives for technology developers and plant operators to promote these experiences.
Recommendations
High fuel prices and high CO2 prices are a key incentive to both implement efficient technologies as well as push technological development for further improvements. Therefore
the use of the emissions trading scheme (ETS) is a good policy option for stimulating efficiency improvements. The rules applied in the ETS should then be set in a way that CO2
prices are sufficiently high. Prices above 20 €/tonne already have quite a large impact on
generating costs.
Since most operational power plants and also quite a number of planned power plants are
not designed as capture-ready, clear legislation is needed in this field. Requirements for
capture-readiness should mainly focus on sufficient available space onsite for CO2 capture
equipment and a reasonable distance to storage reservoirs. Also a study is needed to assess necessary changes to the installation when CO2 capture is added and associated
costs. It is not advisable to set strict requirements for pre-investments to be done, since
there is too much uncertainty regarding the optimal type of capture technology to be used.
Also in the field of CO2 transport and storage, no strict requirements can be set, before the
legislative framework for CO2 transport and storage is fully developed.
For CCS to be commercial, prices of CO2 higher than 50 € per tonne are needed. For gasfired power plants even higher prices are needed.
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Table of contents
1
Introduction
2
Overview effi ciency fossil power EU
3
4
9
10
2.1
Fuel mix for power generation
10
2.2
Energy-efficiency fossil-fired power generation
11
Methodology plant analysis
20
3.1
Energy-efficiency
20
3.1.1
3.1.2
Coal-fired power generation
Gas-fired power generation
22
26
3.1.3
3.2
Energy-efficiency by applying BAT
Capture-readiness
27
32
3.2.1
3.2.2
Overview of CO2 capture approaches
Definition of capture readiness
32
36
3.3
3.4
Plant selection
Data gathering
37
41
3.4.1
3.4.2
Participation in questionnaire
Interviews
41
43
Results plant analysis
44
4.1
4.1.1
Energy-efficiency
Pulverised hard coal-fired power plants
44
45
4.1.2
4.1.3
Pulverised lignite-fired power plants
IGCC plants
46
47
4.1.4
4.1.5
Gas-fired power plants
Operational energy-efficiency
48
50
4.1.6
4.2
Results interviews
Capture-readiness
50
53
4.2.1
4.2.2
Gas-fired power plants
Coal-fired power plants
53
54
4.2.3
4.2.4
Characteristics of capture-ready plants
Results interviews
55
56
5
Conclusions and recommendations
58
5.1
5.2
Energy-efficiency
Capture-readiness
58
58
5.3
Recommendations
60
References
61
Appendix
64
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
1
Introduction
In the “Communication on Sustainable Power Generation from Fossil Fuels”, of the European Commission’s energy package (10 January 2007), the European Commission spells
out the need to develop further fossil fuel technologies that will allow near-zero emissions
by power plants. These technologies will combine high-efficiency fuel conversion with carbon dioxide capture and underground storage (CCS). In particular, new fossil fuel power
plants to be commissioned in the period until 2020 should adopt best available technologies (BAT) for energy efficiency ánd should be designed as capture-ready, allowing for the
adding of capture installations at a later stage, once such installations become commercially available.
The objective of this study is to give an overview of new power plants in the European Union (EU) and to see if these plants conform to BAT energy-efficiency levels and can be
considered as capture ready. The study focuses on recently built (in period 1997-2007)
and planned (in the next 10 years) coal-fired and gas-fired power plants3. For this purpose
data is gathered on a plant level.
First, chapter 2 gives an overview of fossil-fired power generation in the EU, with a comparison of energy-efficiency on a country level. Chapter 3 explains the methodology used
for the analysis on plant level. Chapter 4 gives the results of the plant analysis and Chapter
5 draws conclusions.
3
Recently built and planned power plants together are in this study also referred to as “new
plants”.
2
Overview efficiency fossil power EU
In this chapter we give an overview of the amount and efficiency of fossil-fired power generation in the EU, on a country level.
2.1
Fuel mix for power generation
Figure 1 and Figure 2 show the fuel mix for total electricity production in 2005 based on
electricity output. The first figure gives absolute values and the second fuel mix shares.
700
Power generation (TWh)
600
Other renewables
500
Hydro
400
Nuclear
Natural gas
300
Oil
200
Coal
100
U
ni
te
d
G
er
m
a
Fr ny
Ki a n
ng ce
do
m
It a
S ly
S w p ai
ed n
N P en
et o l
he a n
rl a d
C
ze B n d
ch e lg s
R i um
ep
u
Fi b l ic
nl
a
Au n d
st
G r ia
R re e
om ce
P o a n ia
rt
B u u ga
l
D lg a r
en ia
Sl
m
ov H a r
a k un k
R ga
e p ry
ub
Ire l ic
Sl l an
o d
L i ve n
t h ia
ua
Es ni a
to
n
L a ia
L u C t v ia
xe yp
m ru s
bo
ur
M g
al
ta
0
Figure 1 Total power generation by source in 2005
100%
80%
Other renewables
Hydro
60%
Nuclear
Natural gas
40%
Oil
Coal
20%
U
ni
te
d
G
er
m
a
Fr ny
Ki a n
ng ce
do
m
It a
S ly
S w p ai
ed n
N P en
et o l
he a n
rl a d
C
ze B n d
ch e lg s
R i um
ep
u
Fi b lic
nl
a
Au n d
s
G tri a
R re e
om c e
a
Po n ia
rt
Bu u ga
l
D lg a r
en ia
Sl
m
ov H a r
a k un k
R ga
e p ry
ub
Ire l ic
Sl lan
ov d
Li en
t h ia
ua
Es ni a
to
n
L a ia
L u C t via
xe yp
m ru s
bo
ur
g
M
al
ta
0%
Figure 2
10
Relative t otal power generation by source in 2005
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Power generation in the EU is largest in Germany and France with more than 500 TWh. As
a comparison power generation in the United States is 4,300 TWh in 2005 and in China
2,500 TWh.
The share of fossil fuels in the overall fuel mix for electricity generation is 55% for EU-27
(30% coal, 20% gas and 4% oil).
2.2
Energy-efficiency fossil-fired power generation
In this chapter we calculate the efficiency for power generation by fossil fuel type. The data
is based on IEA (2007). We used data for main power producers (excluding autoproduc4
ers). The energy inputs for power plants are based on net calorific value (NCV) . The output of the electricity plants in IEA statistics is measured as gross production of electricity
and heat. This is defined by IEA as the “electricity production including the auxiliary electricity consumption and losses in transformers at the power station”.
The calculation for energy-efficiency in this study is based on Phylipsen et al (2003). The
formula is given below:
E=
P+ H ×s
I
Where:
• E=
Energy-efficiency of power generation
• P =
• H=
Power production from power plant
Heat output from power plant (if any)
• s=
Correction factor between heat and electricity, defined as the reduction in
electricity production per unit of heat extracted
• I=
Fuel input for power plant, based on net calorific value (NCV)
Some power plants produce next to electricity also heat (so-called combined heat and
power (CHP) plant. Heat extraction reduces the energy efficiency of electricity generation
but the energy efficiency for combined heat and electricity production is higher than when
the two are generated separately. Therefore, a correction for heat extraction for CHP
plants has to be applied. This correction reflects the amount of electricity production lost
per unit of heat extracted from the electricity plant(s). For district heating systems, the correction factor varies typically between 0.15 and 0.2. In our analysis we use a value of
0.175. It must be noted that when heat is delivered at higher temperatures (e.g. to indus-
4
The net calorific value (NCV) or lower heating value (LHV) refers to the quantity of heat liberated
by the complete combustion of a unit of fuel when the water produced is assumed to remain as a
vapour and the heat is not recovered. Conversion factors used in this study for converting from
gross calorific value (GCV) to net calorific value (NCV) are 0.9 for natural gas, 0.93 for oil and
0.96-0.97 for hard coal and 0.86 for lignite (IEA, 2007b).
trial processes), the substitution factor will be higher. However, at the moment, the amount
of high-temperature heat delivered to industry by utilities is small in most countries. Phylipsen et al (2003) estimates that the effect of a higher temperature on the average efficiency
is not more than an increase of 0.5 percent point.
The figures below give power generation efficiency for coal, oil, natural gas and overall
fossil-fired power generation, respectively. Besides EU-27 also Japan, United States,
China and South Korea are included for comparison reasons. To take into account uncertainty in energy-efficiency values for individual years, we take the average energy efficiency for the last three years available.
Coal-fired power generation efficiency
45%
43%
Average 2003, 2004 and 2005
Energy-efficiency (%)
41%
39%
37%
35%
33%
31%
29%
27%
De
nm
a
J a rk
pa
Au n
s
P o t ri a
rt u
B g
Ne e lg a l
th ium
er
la
n
Fr d s
an
Ir ce
G el an
er
m d
Un
a
ite F i ny
nl
d
K i an
ng d
do
Sp m
ai
Ko n
re
a
Ita
E U ly
Un P -2 7
ite ola
d
n
St d
a
S w te s
ed
G en
re
Ro e c
m e
S l a ni
ov a
e
E s n ia
to
Cz
ni
ec
a
h Ch
Re in
pu a
H u bl i c
ng
Sl
ov B u a r
a k lg y
Re ar i
pu a
bl
ic
25%
Figure 3 Gross energy- efficiency coal -fi red power generation ( base d on IEA,
2007)5
The energy efficiencies for coal-fired power generation range from 28% for Slovak Republic to 43% for Denmark.
5
Cyprus, Latvia, Lithuania, Luxembourg and Malta are not included because coal-fired power
generation is zero.
12
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
xe S pa
m in
b
P o o ur
rt u g
Un
ga
ite
l
d
K i I ta
ng ly
do
K m
B e ore
lg a
i
F i um
nl
a
I r e nd
la
EU n d
N Fr 2 7
et an
he c
rla e
G nd s
re
e
A u ce
De st r
n ia
G ma
er rk
m
an
Un
ite J a y
d pa
St n
at
e
Ch s
S l in
ov a
Sl
ov H e n
a k u n ia
R e gar
pu y
E s bl i c
to
n
La i a
Cz
ec S w tv i
a
h
Re ed e
pu n
b
P o lic
Li l an
th d
u
Ro a n
m ia
B u a ni
lg a
ar
ia
Lu
Energy-efficiency (%)
pa
n
I
F r ta ly
an
E ce
D U
Ne e n -2 7
th m a
er rk
G l an
er d s
Un
m
ite F any
d i nl
K i an
ng d
P o d om
r
Un A t u g
ite us a l
d t ri
St a
S w ate
ed s
P o en
la
G nd
re
e
I re ce
la
Ko n d
re
Sp a
Cy a i n
pr
u
C s
B h in
el a
g
Hu i u m
ng
a
M ry
R al
o m ta
a
E s n ia
S
to
lo
ni
va
k La a
Re tv
p ia
B u u bl
l ic
Li gar
t h ia
Cz
ua
ec S l ni
h ov a
R en
ep i a
ub
lic
Ja
Energy-efficiency (%)
50%
Oil-fired power generation efficiency
45%
6
7
Average 2003, 2004 and 2005
40%
35%
30%
25%
20%
Figure 4
2007)6
Gross energy-efficiency oil-fired power generation (based on IEA,
For oil-fired power generation the efficiencies range from 23% for Czech Republic to 46%
for Japan.
60%
Gas-fired power generation efficiency
55%
50%
Average 2003, 2004 and 2005
45%
40%
35%
30%
25%
Figure 5 Gross energy-efficiency gas-fired power generation (based on IEA,
2007)7
Luxembourg is not included because oil-fired power generation is zero.
Cyprus and Malta are not included because gas-fired power generation is zero.
For gas-fired power generation the efficiencies range from 30% for Bulgaria to 55% for
Spain.
Average fossil-fired power generation efficiency
60%
55%
Average 2003, 2004 and 2005
Energy-efficiency (%)
50%
45%
40%
35%
30%
25%
Th
Lu
xe
m
bo
ur
g
I ta
e
B
N
e
Un e lg ly
ite th e ium
d rla
Ki n
ng ds
do
J m
De ap
nm an
A u ark
P o st ri
rt u a
I re ga l
l
F r an d
an
F i ce
nl
a
E U nd
Sp 2 7
a
K in
Un G e ore
r
ite m a
d an
St y
a
G te s
re
P o ece
S w lan
d
Hu ed e
ng n
Sl a
ov r y
e
Cy nia
p
E s ru
to s
n
La ia
Ro tv
Cz
m ia
an
ec
h Ch ia
Re in
pu a
bl
ic
Sl
ov Li M al
t
a k hu t a
Re a n
p ia
B u ubl
lg ic
ar
ia
20%
Figure 6 Gross ener gy-efficiency fossi l-fired pow er generation (base d on IEA,
2007)
For overall fossil-fired power generation, the efficiencies range from 30% for Bulgaria to
55% for Luxembourg.
Figure 7 shows the development of the energy-efficiency for EU-27 per fuel source.
14
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
50%
Coal
48%
Oil
46%
Gas
44%
Average f ossil
42%
40%
38%
36%
34%
05
20
04
20
03
20
02
20
00
01
20
20
99
19
98
19
97
19
96
19
94
95
19
19
93
19
92
19
91
19
19
90
32%
F i g u r e 7 A v e r a g e e n e r g y - e f f i c i e n c y E U 2 7 p e r f u e l s ou r c e ( b a s e d o n I E A , 2 0 0 7 )
The energy-efficiency of gas-fired power generation shows a sharp increasing trend from
33% in 1990 to 50% in 2005. For coal-fired power generation the efficiency increased from
35% in 1990 to 38% in 2005 and for oil-fired power generation from 36% to 40%.
Figure 8 shows the increase in power generation per fuel source.
1,200,000
Power generation (GWh)
1,000,000
800,000
Coal
Oil
600,000
Gas
400,000
200,000
0
1990 1991 1992
1993 1994 1995 1996 1997
1998 1999 2000 2001 2002
2003 2004 2005
Figure 8 Power generation in EU27 per fuel sour ce (IEA, 2007)
Coal-fired power generation has remained equal at around 900 TWh. Gas-fired power generation increased from 140 TWh in 1990 to 550 TWh in 2005. Oil-fired power generation
decreased from 190 TWh to 100 TWh in the same period.
Figure 9 shows the energy-efficiency for gas-fired power generation in combination with
the average age of the gas-fired power plant fleet, based on IEA (2007) and Platts (2008).
The average age is weighted by capacity. It would be better to weigh the average age by
actual load hours of the capacity, but this information is not available.
Gas-fired power generation
60%
55%
50%
45%
y = -0.01x + 0.59
R 2 = 0.81
40%
35%
30%
25%
0
5
10
15
20
25
30
35
Figure 9 Average energy-effi cie ncy in 2005 and average age of operat i onal capacity by the end of 200 5 (weighted by capacity)
There seems to be a clear trend between the average age of the power plants (weighted
by capacity) and average country energy-efficiency. There are two exceptions where the
capacity is relatively new and the efficiency is low (these excluded from the figure). This is
discussed in more detail after the next table. Table 3 gives the underlying data per country.
16
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Table 3 Energy-efficiency in 2005 and average age of operational capacity by
the end of 2005 (weighted by capacity) (Poland and Sl ovenia are excluded from the figure)
Gas-fired plants
Poland
Spain
Portugal
Slovenia
Luxembourg
United Kingdom
Belgium
France
Denmark
Italy
Finland
Greece
Netherlands
Austria
Hungary
Ireland
Czech Republic
Latvia
Germany
Sweden
Slovakia
Estonia
Bulgaria
Lithuania
Romania
Average
age
3
4
4
4
5
10
10
10
10
11
12
13
16
17
17
17
18
20
21
22
24
25
29
29
33
Energyefficiency
34%
58%
55%
42%
55%
52%
51%
48%
45%
55%
49%
43%
46%
46%
40%
49%
35%
34%
46%
34%
37%
36%
32%
33%
32%
Most countries with a relatively new power plant fleet have also high energy-efficiency for
gas-fired power generation. A few exceptions are:
In Slovenia gas-fired power generation consists of one gas-fired power plant that is
build in 2001. The energy-efficiency in 2005 is only 42%. This is because the
power plant has only one gas turbine and is not a combined cycle. The power
plant has two units with a capacity of only 230 MW and is owned by company
Termoelectric Brestanica.
In Poland, all gas-fired power plants are built after 1998 but the average energyefficiency is only 34% in 2005. The reason is that these are all small-scale CHP
plants with a single-cycle and a capacity range of 2 - 150 MW per plant. For small
scale plants it is generally not worthwhile to build a combined-cycle plant, so the
energy-efficiency of these small-scale plants cannot be compared to large scale
NGCC units.
The gas-fired power plant fleet in Spain is quite new and the energy-efficiency is correspondingly high with 58% in 2005. Please note that the average energy-efficiency for 2003,
2004 and 2005 is 55%, so the value for 2005 may be exceptionally high or erroneous.
In Denmark the average age of the gas-fired power plant fleet is 10 years and the average
energy efficiency is 45%. Most gas-fired power plants in Denmark are small-scale CHP
plants below 100 MW.
Although the average age of gas-fired power plants in Germany is relatively high 21 years,
the energy-efficiency is quite high with 46%. 30% of the gas-fired power plants in Germany
are combined-cycles.
Figure 10 shows the energy-efficiency for coal-fired power generation in combination with
the average age of the coal-fired power plant fleet, based on IEA (2007) and Platts (2008).
Coal-fired power generation
45%
43%
41%
39%
37%
35%
y = -0.004x + 0.481
R2 = 0.275
33%
31%
29%
27%
25%
0
5
10
15
20
25
30
35
Figure 10 Average ener gy-efficiency in 2005 and average age of oper ational capacity by the end of 200 5 (weighted by capacity)
The average age of coal-fired power plants is much higher than for gas-fired power plants.
There seems to be some relationship between age and energy-efficiency. But since the
age of the fleets is quite high, many other factors play a role in energy-efficiency like applied modernisations. Table 4 gives the underlying data per country.
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Table 4 Energy-efficiency in 2005 and average age of operational capacity by
the end of 2005 (weighted by capacity)
Coal-fired plants
Portugal
Ireland
Netherlands
Austria
Denmark
Greece
Germany
Spain
Finland
Romania
Poland
Bulgaria
France
Sweden
Czech Republic
Italy
United Kingdom
United Kingdom
United Kingdom
Slovenia
Belgium
Slovakia
Hungary
Average
age
16
19
21
21
23
23
25
25
26
27
29
30
30
31
31
31
33
33
33
34
34
36
37
Energyefficiency
39%
40%
43%
41%
43%
35%
40%
39%
38%
35%
37%
29%
39%
31%
31%
37%
39%
39%
39%
36%
38%
26%
32%
3
Methodology plant analysis
This chapter gives the methodology that is used for the analysis on plant level. The aim is
to give an overview of energy-efficiency and capture-readiness of recently built and
planned power plants in the EU. For this purpose we assess the level of energy-efficiency
that can be achieved by applying best available techniques (BAT) (Section 3.1). Furthermore we look at requirements that power plants should meet to claim capture-readiness of
the plant (Section 3.2). As a second step we give an overview of recently built and planned
power plants in the EU (Section 3.3). Section 3.4, lastly explains the means of data gathering.
3.1
Energy-efficiency
This section gives an overview of the energy-efficiency that would be expected by applying
best available techniques (BAT) per type of fossil-fired power plant. This includes an assessment of the effects of different external factors on energy-efficiency such as climate
conditions and load hours.
The definition for energy-efficiency for the plant analysis is based on Phylipsen et al
(2003). The formula for calculating energy efficiency of power generation is given below:
E=
P+ H ×s
I
Where:
• E=
Net energy-efficiency of power generation
• P =
• H=
Net power production from power plant
Heat output from power plant (if any)
• s=
Correction factor between heat and electricity, defined as the reduction in
electricity production per unit of heat extracted
• I=
Fuel input for power plant, based on net calorific value (NCV)
8
8
The net calorific value (NCV) or lower heating value refers to the quantity of heat liberated by the
complete combustion of a unit of fuel when the water produced is assumed to remain as a vapour
and the heat is not recovered. Conversion factors used in this study for converting from gross calo-
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Heat extraction
Some power plants produce next to electricity also heat (so-called combined heat and
power (CHP) plant. Heat extraction reduces the energy efficiency of electricity generation
but the energy efficiency for combined heat and electricity production is higher than when
the two are generated separately. Therefore, a correction for heat extraction for CHP
plants has to be applied. This correction reflects the amount of electricity production lost
per unit of heat extracted from the electricity plant(s). For district heating systems, the correction factor varies typically between 0.15 and 0.2. In our analysis we use a value of
0.175. It must be noted that when heat is delivered at higher temperatures (e.g. to industrial processes), the substitution factor will be higher. However, at the moment, the amount
of high-temperature heat delivered to industry by utilities is small in most countries. Phylipsen et al (2003) estimates that the effect of a higher temperature on the average efficiency
is not more than an increase of 0.5 percent point.
Net and gross efficiency
Unless otherwise specified, the energy-efficiencies for the plant analysis are based on net
electricity generation. The net energy-efficiency is based on the primary fuel input and the
power send out of the plant. In contrast, gross power generation is measured as direct
generator output. The difference is the auxiliary power which is consumed inside the power
plant by equipment such as crushers, fans, pumps and environmental control equipment.
Design and operational efficiency
Two types of energy-efficiency are used in this study; design energy-efficiency and operational energy-efficiency.
Design energy-efficiency (also called name-plate efficiency) is a static energy-efficiency
and basically gives the energy-efficiency if a plant operates at best performance. Design
energy-efficiency is influenced by a number of factors like the nature and quality of the fuel,
turbine type, operating temperature, steam send out, climate conditions, type of cooling
systems etc.
The operational energy-efficiency is defined as the year-round average efficiency of a
plant. An important factor influencing operational efficiency is the amount of load hours. In
this section, we will discuss the most important parameters that influence the design and
operational energy-efficiency of a power plant.
rific value (GCV) to net calorific value (NCV) are 0.9 for natural gas, 0.93 for oil and 0.96-0.97 for
hard coal and 0.86 for lignite (IEA, 2007b).
3.1.1
Coal-fired power generation
There are currently two types of technologies used for coal-fired power generation, pulverised coal (steam cycle) and coal gasification combined-cycle (IGCC). We will discuss the
state of the art for both types separately.
Pulverised coal
Pulverised coal combustion was first developed in the 1920s. In this form of combustion,
coal is first ground into fine particles. In the early days, the unit size of pulverised combustors was small (typically 30 MWe). The pressure and temperature of the steam produced
were also moderate, resulting in relatively low power generation efficiencies (typically
20%). Over time, with technological developments and experience, both the unit size, and
steam pressure and temperature, have gradually increased over the years (Hendriks at al,
2004).
The main losses in coal-fired power plants occur in the steam boiler and in the turbine section. Combustion is generally 99-99.5% complete so that normally very little energy loss
arises through unburnt fuel. This is achieved through fine grinding of the coal, optimum
burner design and careful control of the coal and air supplies (IEA, 2007b).
Large state-of-the-art pulverised coal boilers have efficiencies of around 93%. Losses occur mainly as heat remaining in the flue gases. Where very moist coals such as lignite are
burnt, a major decrease in boiler efficiency will occur because of high temperature heat
used to dry the coal. Methods for pre-drying such coals using low-grade heat with latent
heat recovery are in development and, when implemented these may raise efficiency by up
to four percentage points. [IEA, 2007b]
The theoretical thermal efficiency of a steam turbine is a function of both temperature and
pressure, with the dependence on temperature being much stronger. Over the temperature
range of 500 to 800°C, efficiencies vary almost linearly with steam temperature. Thus,
there is an incentive to boost steam temperature in order to achieve higher thermal efficiency (Ruth, 2003). The temperature of steam increased by 60 °C over the last 30 years.
It is expected that steam temperatures will rise another 50-100 °C in the next 30 years
(Viswanathan, 2000).
Coal-fired power plants can be categorized by steam pressure. Three categories are distinguished: sub-critical plants, supercritical plants and ultra supercritical plants.
Before 1970 sub-critical plants were used with a steam pressure below 200 bars and temperature of 540°C. These plants can achieve generation efficiencies of up to around 39%
(Hendriks at al, 2004).
In the 1970s, pulverised coal-fired supercritical steam cycle plants, were developed and
introduced. These plants use a steam pressure of around 250 bars and temperature of
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
around 560°C. Such plant can achieve generation efficiencies of up to around 42%
(Hendriks at al, 2004).
Of late, several ultra supercritical units, have been ordered or are under construction.
These units are designed to operate at steam pressures up to about 290 bars and temperatures up to over 600°C to achieve a generation efficiency of up to 47% (Hendriks at al,
2004).
Table 5 gives an overview of the characteristics of the three groups.
Tabl e 5 Overview pul ver ized coal technol ogies (Hendriks et al , 2004)
Type of coal plant
Temperature (°C)
Pressure (Bar)
Maximum
efficiency
Sub-critical
538
167
39%
Supercritical
540 – 566
250
42%
Ultra-supercritical
580 - 620
270 - 290
47%
One of the first ultra supercritical plants was unit 3 at Nordjyllandsværket in Denmark,
which is a double reheat unit with steam parameters 290 bar, operating at 580°C and a net
efficiency of 47%. The unit went into operation in 1998. This led to the start of the large
European research project: The Advanced (700°C) PF Power Plant. The aim of the project
is to raise steam temperatures to 700°C resulting in efficiencies in the range of 52 to 55%
efficiency. Commercial availability is not expected before the period 2010 to 2015 (Tech-wise A/S, 2003a).
Figure 11 shows the trend for energy-efficiency improvement for coal-fired power plants.
Figure 11 Past and projected future development in efficiency of Elsam’s coalfired power plants (Tech -wise A/S, 2003b)
Coal gasification combined cycle (IGCC)
Coal IGCC stands for coal integrated gasification combined cycle, which is a powergenerating technology based on the gasification of coal under partial oxidation. The coal is
partially oxidized with almost pure oxygen or air in a gasification based system. Resulting
from the gasification process is syngas, which consists primarily of carbon monoxide (CO)
and hydrogen (H2). After cleaning the syngas of (predominantly sulphur) impurities, “the
carbon monoxide (CO) of the syngas can be converted into carbon dioxide (CO2) by a water gas shift reaction performed through the injection of steam, leaving large quantities of
H2. The CO2 is then removed from the syngas through a conventional scrubbing process,
leaving almost an almost pure H2 as fuel, which is burned as fuel in a gas turbine cycle
(Eurelectric, 2007). The gas turbine drives a generator, which generates electricity. Subsequently, the exhaust gases from the gas turbine is transferred back to the gasifier or the air
separation unit, while exhaust heat from the gas turbine is recovered and used to boil water, creating steam for a steam turbine-generator which is the second cycle of the combined cycle technology.
On the one hand, efficiency losses occur when gasifying the coal but on the other hand,
efficiency gains occur through the subsequent use of the combined gas- and steam-turbine
cycle (of which the gas turbine requires a gaseous fuel). Also, when carbon capture and
storage is applied to IGCC, there will be (potentially) less efficiency loss than in a pulverised coal-fired power plant since the CO2 does not need to be removed from the diluted
exhaust gas (also known as flue-gas) but can (more) easily be isolated during the separation of H2 and CO2. Examples of IGCC plants that have been built are:
Since 1994, a 253 MWe oxygen-blown IGCC (Shell/Siemens technology) operates
in Buggenum, the Netherlands. Some design changes were made in 1997 to solve
a few operational problems. After that the net operational efficiency obtained at
this plant is 43%. The plant currently produces power for the commercial market
and operates without major difficulties (Hendriks at al, 2004).
Since 1996, a 252 MWe oxygen-blown IGCC operates at Wabash River, Indiana.
The demonstration period was closed in 1999. The net operational efficiency obtained is 40.2% (Wabash, 2000).
Since 1996 a 250 MWe oxygen-blown IGCC (Texaco/GE technology) operates in
Mulberry, Polk country, Florida, including full heat recovery, and conventional cold
gas cleanup. The net operational efficiency obtained is 41% (BINE, 2006).
Since 1997 a 335 MWe oxygen-blown IGCC (PERNFLO/Siemens V94.3 technology) operates at Puertollano in Spain. The net operational efficiency obtained is
45% (WEC, 1998).
Since 1996, a 351 MWe lignite-fired oxygen-blown IGCC Plant (Sasol-Lurgi Technology) operates in Vresova, Czech Republic. The plant reached a net operational
efficiency of 44%. In 2005 the plant was enhanced with a capacity of 430 MWe
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
with GSP technology and a net efficiency of 41% (BINE, 2006). The GSP technology (developed by Siemens) is flexible for different types of coal: lignite, hard coal
and refinery residues.
Recently built and planned coal fired power units in the EU
Based on information from Platts (2008), we see most of the operational plants in the EU
are pulverised coal plants. Only very small capacity is based on the innovative IGCC technology (1 GW in operation, 2 GW planned), see figure below.
200,000
180,000
160,000
Capacity (MW)
140,000
120,000
Pulverised coal
100,000
IGCC
80,000
60,000
40,000
20,000
Operational
before or in
1997
Operational >
1997
Under
construction
Planned
Figure 12 Recent and pl anned coal power plants in the EU (Platts, 2008)
Most units currently under construction fall under the category ultra supercritical units with
a steam temperature above 580 °C (Platts, 2008).
3.1.2
Gas-fired power generation
For gas-fired power generation a number of different technologies can be used. These are:
• Internal combustion engine
•
•
Steam turbine
Gas turbine
•
Combined-cycle (gas and steam turbine)
Figure 13 shows the technologies used for recently built and new gas-fired power plants in
the EU plants.
120,000
100,000
Capacity (MW)
80,000
Steam turbine
Internal combustion engine
60,000
Gas turbine
Combined-cycle
40,000
20,000
Operational >
1997
Under
construction
Planned
Figure 13 Power unit type for gas-fired units (Platts, 2008)
The combined cycle technology is dominating both in the capacity recently entered into
operation and in the planned plants. In the operational plants also quite some gas turbines
are included. Nearly all of plants are smaller than 50 MW and more than 50% of these are
CHP plants. Combustion engines are only used for very small scale applications below 10
MW (Platts, 2008). For large-scale power and CHP plants the combined-cycle technology
is in most cases used.
In the gas turbine of a combined cycle plant, the input temperature to the turbine (the firing
temperature), is relatively high (900 to 1,430 °C). The output temperature of the flue gas is
consequently also high (450 to 650 °C). This is high enough to provide heat for a second
cycle which uses steam as the working fluid (a Rankine cycle).
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Since the 1980s the efficiency for the gas turbine in combination with a steam cycle has
gradually improved. Were efficiencies in 1980s were still well below 50%, currently the
most modern combined cycles can have efficiencies of about 59-60% (Hendriks at al,
2004).
3.1.3
Energy-efficiency by applying BAT
In this section we summarize the energy-efficiency that can be reached in a power plant by
applying best available techniques today. Also we look at different local circumstances that
influence energy-efficiency.
Table 6 gives current energy-efficiency by applying BAT per type of fuel and the table
gives an example of the current best practice plant (based on available information for this
study). The BAT efficiencies are applicable for large-scale power plants (typical unit size of
400 MW for natural gas and 800 MW for coal) and a cooling water inlet temperature of 20
ºC.
T a b l e 6 B A T e n e r g y e f f i c i e n c y i n 2 0 0 8 ( b a s e d o n E u r o p e a n C o m m i s s i o n ( 2 0 0 6 ) 9,
Hendriks et al. (2004), Power Technol ogy (2008))
Technology
Fuel
Net
Best practice plant10
energyefficiency
Pulverised coal steam cycle
Coal
46%
(ultra-supercritical)
Nordjyllandsvaerket, Denmark, Vattenfal
Operational in 1998, 580 ºC
Efficiency 47%
Lignite
43%
11
Niederaussem, Germany, RWE
Operational in 2002, 580 ºC
Efficiency 43%
Coal gasification combined
Coal
46%
cycle (IGCC)
Puertollano in Spain, 335 MW
Operational in 1997
Efficiency 45%
Natural gas combined cycle
Natural
(NGCC)
gas
59-60%
12
Baglan Energy, UK, 525 MW
Operational in 2003, 1430 ºC (GE H system)
Efficiency 60%13
9
“Reference document on BAT for Large Combustion plants” (European Commission, 2006)
Based on available information for this study.
11
The high energy-efficiency of 47% is partly due to low temperature sea-water cooling. IEA
(2007b) estimated the efficiency by 20 ºC cooling water temperature to be 45%.
12
For a new IGCC plant it is expected that 46% of net efficiency can be reached based on
improved technological design.
13
It seems the 60% efficiency is difficult to reach due to environmental permits that dictated the
design of the cooling water system, as well as natural operating degradation through use (Sanford,
2007).
10
Local circumstances
Local circumstances influence the efficiency that can be achieved in a power plant. The
main factors that influence the efficiency of a power plant are:
Cooling method (cooling towers, sea-water cooling)
Climate conditions (cool versus warm climate)
Size of power plant
Altitude
Flue gas cleaning
Biomass cofiring
Quality of maintenance
Fuel quality
Load hours
We discuss these factors in more detail below.
Cooling method
Plants with surface or sea water-cooling systems have a higher plant efficiency than comparable plants using cooling towers. The cooling methods that can be applied depend on
local circumstances, like the availability of sufficient surface water and existing regulations.
The effect of cooling method on efficiency may be up to 1-2 percent points (Phylipsen et al,
1998).
Climate conditions
Weather conditions influence the operation of steam cycles and gas turbines. Plants in
warmer climates have therefore a structural lower efficiency than comparable plants in
cooler climates.
The ambient temperature influences the temperature of the cooling medium. Figure 14
shows the efficiency loss as function of the cooling water temperature for different type of
turbines. The effect of higher cooling water can be up to 2-2.5% (1-1.5 percent point).
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Figure 14 Efficiency loss due to higher (once through) cooling water temperatures (KEMA, 2004)
There is also a secondary effect of a high ambient temperature. When the ambient-air temperature increases, its specific mass is reduced. In order to ensure the same air volumetric
flow, the mass flow is reduced, causing the power of a gas turbine to fall. The impact of
this on energy-efficiency is estimated to be up to 1.5-2 percent point for a difference in ambient temperature of 35 ºC (Arrieta and Lora, 2004).
Size of the power plant
Large-scale power plants can reach a higher efficiency level than small-scale power plants.
Since this study focuses on plants with units above 300 MW, the effect is small. Siemens
(2008) and Alstom (2008) estimate that the effect is smaller than 0.5 percent points (for a
400 MW unit in comparison to an 800 MW coal-fired unit).
Flue gas cleaning
Pollution abatement technologies can affect the efficiency of power generation, as it leads
to increased internal consumption of power and - for specific technologies - steam. The effect on net energy efficiency of pollution control technologies is around 1 percent point for
coal-fired power plants (including wet scrubber for SO2, catalytic reduction (SCR) and
combustion modification for NOx) and 0.5 percent point for gas-fired power plants (SCR
and combustion modification for NOx) (Graus and Worrell, 2006). The use of flue gas
cleaning in the EU is now standard for all recently built and planned power plants.
Altitude
Altitude can be a factor in performance by lower oxygen content in air at higher altitudes.
The amount of the effect is considered to be relatively small (Arrieta and Lora, 2004).
Biomass cofiring
Biomass is increasingly cofired in conventional power plants fired with both hard coal and
lignite. Biomass cofiring leads to a reduction of (net) greenhouse gas emissions and can
also reduce SO2 emissions due to the normally lower content of sulphur in biomass compared to coal. The efficiency of the coal fired power plant decreases with cofiring by up to
0.5 percent point. Still the efficiency of the biomass combustion is usually higher than if it
would be used in dedicated biomass power plants. This is due to economies of scale,
which allow for more efficient combustion techniques.
Maintenance14
Generally the effect of maintenance on operational energy efficiency of a plant is small and
below 0.5 percent point. However in individual cases, where there is a serious deficiency in
maintenance, the effect can be up to 1-5 percent points.
Fuel quality
For coal-fired power plants, fuel quality can have an impact on generation efficiency. The
effect of using coals with a lower ash content can be up to 1 percent point through reduced
grinding and fuel and solids handling energy needs (IEA, 2007).
For gas-fired power generation, the type of gas can have a large impact on energyefficiency. The maximum efficiency that can be reached in a combined-cycle designed to
be able to use different types of gas (e.g. industrial process gas) is significantly lower than
a 100% natural gas combined-cycle. However the use of process gas is relatively small
compared to the use of natural gas.
Load hours
Operational energy-efficiencies will be a few percent lower than design efficiencies due to
start-up and shutdown of the plant. This especially impacts the energy-efficiency of peakload plants. To estimate these efficiency losses the concept of operational efficiency is
used. Operational efficiency describes the efficiency of the conversion of energy input to
energy output over the period of one year.
14
Based on telephone interviews with several power plant suppliers.
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Table 7 Comparison of net efficiency and operati onal ef ficiency f or coal and gas
c o m b i n e d c y c l e - p o w e r p l a n t u n i t s ( b a s e d o n V G B P o w e r t e c h , 2 0 0 4 ) 15
Technology
Electrical
Power
Full-load
hours
Net design efficiency
Operational
efficiency
Coefficient
46%
40.6%
0.88
46%
42.3%
0.92
46%
44.3%
0.96
46%
45.0%
0.98
46%
40.5%
0.88
46%
41.9%
0.91
46%
43.2%
0.94
46%
44.2%
0.96
59.5%
52.4%
0.88
59.5%
54.1%
0.91
59.5%
55.9%
0.94
59.5%
57.1%
0.96
2,500
Pulverised
Coal
4,000
> 600 MW
6,000
7,500
2,500
IGCC
4,000
> 300 MW
6,000
7,500
2,500
4,000
Gas (CC)
> 300 MW
6,000
7,500
This table indicates that year round operational efficiency is typically 1-2 percent point
lower than design energy-efficiency if the plant operates at 85% capacity (7,500 full load
hours). When the plant operates at 30% capacity the operational efficiency can be 5 to 7
percent points lower than the design efficiency.
In conclusion, the most important factors influencing design energy-efficiency are the type
of cooling method used and the temperature of the cooling water (also influences operational efficiency). This can influence energy-efficiency by up to 2-3 percent points. Flue gas
cleaning is now standard and implemented at virtually all recently built and planned power
plants. The effect of load hours on operational efficiency can be 5-7 percent points.
15
Year round changes in ambient temperature (and cooling water) are taken into account in the
figures.
3.2
Capture-readiness
Capture-ready means that a plant can be equipped with CO2 capture technology while it is
under construction or after it has been built. If a plant is not capture-ready this means it is
either more expensive to add CO2 capture technology or impossible due to insufficient
space at the site or no suitable reservoir to store the CO2 in. This means that is important
for new fossil plants to be capture-ready in order to have the possibility to add CO2 capture
and storage at a later stage.
In order to determine the degree to which planned power plants can be considered to be
‘capture-ready’ we first need to define the concept capture ready further. The main literature source that is used in this study is “CO2 capture ready plants” IEA GHG (2007).
Capture ready is a term frequently used in the planning process for new power plants.
Generally it refers to the fact that carbon capture and storage (CCS) could be applied to
the plant either when the power plant is still under construction or as a retrofit option. However, the definition of capture readiness is still not widely agreed upon.
In this section we will first explore the different technologies for CCS. Then we will define
capture readiness.
3.2.1
Overview of CO2 capture approaches
There are numerous ways to capture carbon dioxide from power plants. These CO2 capture processes can conveniently be divided into three main categories:
1. Post-combustion processes. Carbon dioxide is recovered from a flue gas.
2. Pre-combustion decarbonisation processes. The fossil fuel is converted to a hydrogenrich stream and a carbon-rich stream.
3. Oxyfuel processes. A concentrated CO2 stream can be produced by the exclusion of
N2 before or during the combustion/conversion process.
The different processes are compared in a schematic overview in Figure 15 and will be described in further detail below.
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Figure 15 Schematic overview of CCS technologies (Jordal and Anheden 2005)
Depending on the type of power plant, one or more types of capturing can be applied.
The post-combustion process is in principle applicable to all types of power plant as it
can be regarded as an add-on process, treating the flue gases of the power plant. The current technology of choice for post-combustion CO2 capture is an absorption processes
16
based on chemical solvents . The process utilises the reversible nature of the chemical
reaction of an acid or sour gas with an alkaline solvent (IPCC, 2005). The flue gas in the
case of amine based systems needs to be pre-treated to reduce NO2 and SO2 concentrations to very low levels to prevent an irreversible reaction with the solvents. The CO2-rich
gas reacts with the amine (input products of reaction) and is later regenerated at higher
temperatures to create a highly pure CO2 stream.
A disadvantage of the absorption process is the high energy consumption of the process
which decreases energy-efficiency of the plant by typically 6 to 10 percent points.
The following gives a view of the required technological changes and design implications
for fossil power plants with post combustion CO2 capture (IEA GHG, 2007):
• Post combustion CO2 capture, basically an end of pipe approach, does not require
changes to the boiler design and combustion process. To reduce energy use for
the desorption process; the required heat needs to be extracted from the turbines,
so some modifications need to be made to this section. Furthermore sufficient
space should be available at the plant site for the absorber and desorber section of
the capture unit.
16
Other technologies are currently under research like cryogenic destillation, where flue gases are
cooled to –130 and the CO2 becomes solid.
•
The fuel type and environmental regulations in place determine whether SOx levels
are low enough to meet the stringent requirements of the amine scrubber. The re3
quirements for the amine scrubber are much lower (10 to 30 mg/Nm with 6% oxygen content dry volume) than current limits imposed by EU regulation (200
3
mg/Nm with 6% oxygen content) in the EU’s Large Combustion Plant Directive).
This implies that depending on the plant and post-combustion technology extra or
•
improved cleaning of the flue gases is required.
An NO2 concentration in the flue gas of up to 40 mg/ Nm3 (with 6% O2 v/v dry) is
considered as acceptable for further processing in the amine CO2 capture plant. If
NO2 concentrations exceed the aforementioned level, further combustion control or
post combustion DeNOx equipment (SCR or SNCR) is needed to bring the NO2
level to an acceptable level.
•
So far amine CO2 plants have been operating successfully at flue gas particulate
levels of up to 5 mg/Nm3 (with 6% O2 v/v dry). If this level is exceeded by current
technology at the site, space should be made available for additional particulate
removal units.
•
Additional space has to be provided for additional air compression equipment, expansion of the waste water treatment plant, equipment associated with the additional auxiliary electrical load.
The pre-combustion decarbonisation process is significantly more integrated in the total plant concept and is realistically seen only applicable to combined cycle plants. In principle it can be applied to all kind of fuels, but for gaseous fuels it seems less favourable. In
this process the fuels are converted into a gas consisting of mainly CO2 and H2. The CO2
is than separated from the H2 typically using physical solvent systems.
The following gives a view of the required technological changes and design implications
for pre-combustion decarbonisation process (IEA GHG, 2007):
•
Additional space has to be provided for a two-stage shift reactor, a supplementary
acid gas removal column (or modification of existing column), heat exchangers associated with the aforementioned units, a CO2 drying and compression plant, a
modified gas turbine burner systems, a high capacity gas feed pipes to the gas turbine combustor and the inclusion of a selective catalytic reduction (SCR) unit (if
required) within the HRSG.
The oxyfuel process is applicable to all types of power plants. This technology replaces
the combustion air with a mixture of near pure oxygen, generated through an air separation
unit (ASU), and a CO2 rich flue gas recycle stream. The resulting flue gas consists predominantly of CO2, H2O and contaminants such as NOx and SO2. It should be noted that
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
for this process in combined cycles a gas turbine needs to adapted or developed which
can operate with a CO2 rich flue gas as the working medium.
The following gives a view of the required technological changes and design implications
for oxyfuel process (IEA GHG, 2007):
• The incorporation of an oxyfuel process requires approximately two thirds of flue
gas recycle stream to maintain steam conditions and similar boiler performance
compared to the pre-capture scenario.
•
The key-feature of an oxyfuel plant in comparison to a conventional plant are: an
air seperation unit (ASU), a CO2 compression and inerts removal plant and heat
exchangers for low grade heat recovery. Additional space will be required for at
least the above mentioned equipment.
First application of CCS
Which of the capture processes will ultimately be the preferred ones is difficult to say at
this moment of development. It is very well possible that more capture technologies will coexist depending on local plant conditions, preferred fuel and type of plant. The following
information is based on presentations from Alstom, Siemens, IPG, Enel and Edf at the
PowerGen conference in Milan 2008.
Post combustion is believed to have the principal role in the following years and the earliest commercial development. This conviction comes from the high experience in the amine
scrubbing processes. The implementation of post-combustion processes seems to be suitable both for retrofit and for new installations. Another important aspect is that this technique is also suitable for other sectors like steel, aluminium and concrete industries. Some
pilot plants are under construction or in planning in Europe and some demonstration plants
will be commissioned before 2015, permitting a possible commercial deployment in the
years after.
Oxy-fuel combustion needs some more time and R&D effort before it can be applied at an
industrial scale. This is due to the needed further technological development of coal combustion in an oxygen, carbon dioxide and steam atmosphere. High fuel flexibility is one of
the main advantages of the oxy-fuel technology and reason for the development of quite a
number of (pilot) plants by some important companies. According to their roadmaps these
small scale demonstrating plants will permit oxy-fuel to be full commercial from 2020. A 30
MWth pilot plant is currently being built by Vattenfall and will start operation in the second
half of 2008. The first large scale demonstration plant (a 320 MWe oxy coal combustion) is
expected to be operational in 2014 in Italy.
Pre-combustion is expected be applied on large scale in a later stage, as it seems now to
find reluctance from some energy producers. They should shift from a conventional system
to a different power generation system. An advantage is that it can be used with circulating
fluidised bed systems, thereby demonstrating a good flexibility. Some other important
benefits of pre-combustion capture are connected with lower pollutant emissions, a well
proven capture process and lower water consumption.
Figure 16 gives a road map for the commercialisation of CCS technology.
Figure 16 CCS deployment timeline (Alstom - Milan PowerGen 2008)
3.2.2
Definition of capture readiness
While capture readiness has different implications for the different plant technologies there
are certain factors which have to be considered in any case. These factors include (IEA
GHG, 2007):
A study on the possible options for CCS in terms of technology and feasibility.
An assessment should be made of the elements of the plant that would need to be
adapted when adding CO2 capture equipment, their place in the plant layout and
their physical size.
An assessment of the possible pre-investments that can be done in comparison to
the costs of making changes when the power plant is built.
The availability of sufficient space for the required CCS technology during operation as well as during construction. At the same time normal operation of the existing plant has to be assured both during construction and operation of CCS.
36
An assessment of a storage site and a credible route to the storage site is needed.
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
3.3
Plant selection
The identification of recently built or planned fossil power plants in the EU is mainly based
on the World Electric Power Plants (WEPP) database from Platts (2008).
In this study we focus specifically on large-scale coal and gas-fired power generation. Focusing on those two fuels reflects the overall developments of installed capacity in the
European Union, like presented in Figure 17. New oil-fired power generation in the EU is
limited. As can be seen from the figure, recently built or planned gas-fired power plants
have the largest share in terms of production capacity.
700,000
600,000
Capacity (MW)
500,000
Planned
400,000
Under construction
Operational > 1997
300,000
Operational (excluding recent)
200,000
100,000
Coal
Natural gas
Oil
Total fossil
Figure 17 Total fossil capacity in EU by fuel type an d status
In the EU, nearly 345 fossil-fired power generating units (> 50 MW) have come in operation in the period 1998-2007, with a total capacity of 75 GW. 100 power generating units
are currently under construction with a total capacity of 33 GW and nearly 400 units are
planned with a total capacity of 161 GW. 65 GW of the planned capacity is included in the
Platts (2008) database without an estimated year of completion and without details about
the technology that will be used. We consider these projects therefore as being in an early
stage of planning. Please note that a power plant typically consists of more than one unit
so the amount of new power plants in smaller than the above-mentioned number of units.
Figure 18 - Figure 20, which give an overview of the amount of fossil capacity per country,
per fuel source divided into plants built after 1997, power plants under construction and
planned power plants.
Operational capacity (MW) > 1997
25,000
Oil
Natural gas
20,000
Coal
15,000
10,000
5,000
Un
Ita
Sp ly
G
ite e r a in
d ma
K
in n y
gd
Be o m
lg
i
Fr um
an
Po c e
P la n
Ne o r d
th t u g
er a l
la
n
G ds
re
e
Ire ce
l
Hu an d
Cz D n g a
ec en ry
m
h
R ar
ep k
ub
Au lic
Sl s t r i
ov a
ak
L u F in ia
xe lan
m d
bo
Cy u rg
p
Sw r us
ed
Sl e
ov n
Ro e n
m ia
an
L a ia
Bu tvia
lg
ar
ia
-
Figure 18 Powe r pl ants i nto oper ation afte r 1997 (MW) (Pl atts, 2008)
The largest share of recently built capacity is gas-fired power plants (72 GW), followed by
coal (11 GW). The capacity of new oil-fired power plants is 8 GW.
Capacity under construction (MW)
9,000
Oil
8,000
Natural gas
7,000
Coal
6,000
5,000
4,000
3,000
2,000
1,000
U
ni
G
It a
e r ly
m
te
an
d
K
y
in
gd
om
Sp
ai
Fr n
an
ce
Po
la
n
G d
r
N
e
e
et
h e ce
r la
nd
s
Ire
la
Po n d
r tu
ga
Au l
st
Bu ria
lg
ar
i
R
om a
an
B e ia
lg
iu
m
La
tv
i
Fi a
nl
an
C d
yp
ru
s
-
Figure 19 Power plants under construction (MW) (Platts, 2008)
38
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Also for power plants under construction, natural gas is most often used (23 GW). Coalfired power plants under construction equal 9 GW and oil-fired power plants only 0.3 GW.
30,000
Oil
Planned capacity (MW)
25,000
Natural gas
Coal
20,000
15,000
10,000
5,000
K
U
ni
te
d
G
er
m
an
Sp y
in a i n
gd
om
N
et
h e Ita
r la ly
n
Po d s
la
F r nd
an
G ce
re
Po e c
rtu e
Cz
ec Be ga
h lg l
R iu
ep m
u
H b li
un c
R ga
om ry
Sl an i
ov a
a
A u k ia
B u st r i
lg a
a
I r e r ia
Sl l an
ov d
e
F i n ia
n
Li lan
th d
ua
C n ia
yp
Sw rus
ed
La en
tv
ia
-
Figure 20 Planned power plants ( MW) (Platts, 2 008)
Of the planned power plants, not yet under construction, 104 GW consists of natural gas,
54 GW of coal and 3 GW of oil-fired power plants.
Of total recent and planned gas-fired power generation, Spain and Italy are largest with respectively 49 GW and 23 GW. In terms of coal-fired power generation Germany has the
highest amount of recently built and planned power plants, in total nearly 18 GW. Poland is
second largest with nearly 5 GW recent and planned capacity.
In this study we focus on large-scale gas and coal-fired power plants with unit size bigger
than 300 MW, owned by utilities. This includes roughly 260 power plants owned by 130
utilities. The capacity of these plants together equals 195 GW, equivalent to 65% of total
recent and planned fossil capacity.
Table 8 gives the amount of recently built and planned capacity in the EU, with units bigger
than 300 MW. 75% of the recently built and planned power plants are gas-fired plants and
25% coal-fired. In terms of capacity, coal-fired power plants account for a slightly higher
share of 33% (65 GW in total capacity of 195 GW).
Ta ble 8 Total re cently built and pl anned coal and gas pow er pl ants (wi th uni ts
bigger than 300 MW) (Platts, 2008)
Pulverized coal
– hard coal
Pulverized
coal - lignite
IGCC
NGCC
Total
Operational > 97
2
6
0
42
50
Under construction
4
4
0
18
26
Planned
47
5
4
131
187
Total
54
15
4
191
263
Figure 21 shows the capacity per country.
60
Natural gas Planned w ithout end year
Number of plants (unit size > 300 MW)
Natural gas Planned
50
Natural gas Under construction
Natural gas Operational > 97
40
Coal Planned w ithout end year
Coal Planned
30
Coal Under construction
Coal Operational > 97
20
10
U
G
Sp
e r a in
m
an
ni
y
te
d
K Ita l
in
y
gd
om
G
N
e t r ee
h e ce
r la
n
Fr ds
an
c
Po e
la
Po n d
r tu
Be ga l
lg
iu
Ir e m
la
n
Au d
s
R tr i
om a
a
H n ia
un
g
C
ze Bu ar y
ch lg a
r
R
e p ia
ub
D
e n lic
m
Li a r
th k
ua
Sl n ia
ov
Sl a k ia
ov
en
i
F
L u in a
xe lan
m d
bo
ur
g
0
Figure 21 New capacity by country (with units bigger 300 MW) (Platts, 2008)
Spain has the highest number of new plants (49 gas-fired and 1 coal-fired plant), followed
by Germany (30 coal-fired and 12 gas-fired plants) and Italy (29 gas-fired and 6 coal-fired
plants).
Figure 22 shows the same data as share in total new capacity per country.
40
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
100%
Natural gas Planned w ithout end
year
Number of plants (unit size > 300 MW)
90%
Natural gas Planned
80%
70%
Natural gas Under construction
60%
Natural gas Operational > 97
50%
Coal Planned w ithout end year
40%
Coal Planned
30%
Coal Under construction
20%
Coal Operational > 97
10%
G
Sp
a
er in
m
an
U
y
ni
te
It a
d
ly
Ki
ng
do
G m
re
N
e
et
he ce
rla
nd
Fr s
an
ce
Po
la
Po nd
r tu
g
Be a l
lg
iu
Ir e m
la
n
Au d
st
R r ia
om
a
H n ia
un
ga
Bu r y
C
ze
ch l ga
r ia
R
ep
u
D bli c
en
m
Li a rk
th
ua
S l ni a
ov
a
Sl kia
ov
en
F i ia
n
Lu
x e l an
d
m
bo
ur
g
0%
Figure 22 New capacity by country (with units bigger 300 MW) (Platts, 2008)
3.4
Data gathering
Since no literature sources are available for this study, with data regarding efficiency and
capture-readiness on a plant level, we sent questionnaires to utilities asking for information
on plant level. Additionally, telephone interviews are held with several utilities and power
plant suppliers.
The questionnaire that was send to the utilities can be found in the Appendix. Regarding
energy-efficiency, questions are asked regarding the design energy-efficiency of the plant
and the operational efficiency. For capture-readiness, questions are asked regarding e.g.
the amount of space that has been reserved, what type of capture technology is considered and which reservoir is considered.
The questions that were asked during the (telephone) interviews can be found in the Appendix.
3.4.1
Participation in questionnaire
Approximately 100 utilities were invited to participate in the questionnaire. For some utilities it was difficult to find a good contact person, sometimes due to the language barrier.
Quite a number of utilities did not want to take part in the questionnaire for confidentiality
reasons. In total, questionnaires were submitted for 67 power plants owned by 30 utilities
with a total capacity of 49 GW. This represents 25% of total new capacity (>300 MW units)
in the EU. Table 9 shows the location of the participating plants and the type of plant.
Ta ble 9 Participation in questionnaire by country
Country
Pulverised
coal – hard
coal
Pulverised
coal –
lignite
IGCC
Austria
Belgium
NGCC
Total
1
1
2
2
Denmark
2
2
7
8
4
8
Hungary
1
1
Ireland
3
3
3
5
Latvia
1
1
Luxembourg
1
1
2
4
France
1
Germany
3
Italy
1
2
Netherlands
1
Poland
1
1
1
Portugal
1
1
Romania
1
1
Slovakia
1
1
Spain
20
20
1
3
7
3
51
67
1
1
United Kingdom
3
Total
13
0
Switzerland
Questionnaires were submitted for power plants in 17 EU countries, consisting of 16 coalfired power plants and 51 gas-fired power plants.
Table 10 shows the status category of the plants. This consists of 18 operational plants, 26
plants under construction and 14 planned power plants.
Ta ble 10 Participation in questionnaire by status category
Pulverised
Pulverised
coal – hard
coal - lignite
IGCC
NGCC
Total
21
21
coal
Operational > 97
Under construction
3
14
17
Planned
10
3
17
30
Total
13
3
52
68
Table 11 shows the participation as share in total recently built and planned power plants
(units > 300 MW). As can be seen, lignite power plants are not represented by the ques-
42
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
tionnaires. For lignite power plants we therefore base the results on publicly available
sources.
Table 11 Participation in questionnaire by status category
Pulverised
Pulverised
coal – hard
coal - lignite
IGCC
NGCC
Total
coal
Operational > 97
0%
0%
-
50%
42%
Under construction /
25%
0%
75%
21%
22%
24%
0%
75%
27%
25%
planned
Total
3.4.2
Interviews
In order to gain more in-depth information we held - in addition to the questionnaires - interviews with a number of utilities and power plant suppliers. Two telephone interviews
were held with utilities planning one coal-fired and one gas-fired power plant. One meeting
was held with a large utility with both recently built and planned coal and gas-fired power
plants. Furthermore three large power plant suppliers were interviewed and one national
agency for new technologies in power plants.
4
Results plant analysis
This chapter gives the results of the plant analysis. First the results for energy-efficiency
are discussed (Section 4.1), followed by the results for capture-readiness (Section 4.2).
4.1
Energy-efficiency
This section gives an overview of the results for energy-efficiency of recently built and
planned power plants, based on the questionnaires and telephone interviews. In some
cases additional information is used from publicly available sources. The efficiencies refer
to the efficiency without CO2 capture. CO2 capture lowers the efficiency by typically 8-10
percent points.
An overview is given for pulverised hard coal-fired power plants (4.1.1), for pulverised lignite-fired power plants (4.1.2), for IGCC plants (4.1.3) and for NGCC plants (4.1.4). In section 4.1.5 information is given about the found difference between design and operational
efficiency. The results from the telephone interview are given in section 4.1.6.
44
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
4.1.1
Pulverised hard coal-fired power plants
Figure 23 gives the results regarding design energy-efficiency that was found for pulverised coal-fired power plants from the questionnaires. Every bar represents one power plant
including the (estimated) year of commissioning. Only questionnaires for planned coal-fired
power plants were submitted so there is no information available for operational plants.
55%
50%
45%
40%
35%
30%
BAT - 2009 2009 2009 2011 2012 2012 2012 2013 2013 2014 2015 2015 2015
2008
Figure 23 Design energy-efficiency (%) for coal- fired power plants
Most planned coal-fired power plants have an energy-efficiency of 45-46%, close to BAT
efficiency. Two exceptions are one power plant with 43% efficiency and one plant with 50%
efficiency:
• The power plant with 43% energy-efficiency has a comparatively small capacity of
460 MW and is based on supercritical circulating fluidised bed (CFB) technology.
As comparison, the other power plants have units larger than 800 MW.
•
The power plant with a projected efficiency of 50% is a demo plant of 500 MW that
aims to proof the commercial and technical feasibility of 700°C steam temperature.
Public sources
Additional information in publicly available sources was found for 7 planned coal-fired
power plants in the period 2010-2012 in Germany, the Netherlands and United Kingdom
(planned by RWE, Electrabel, SSE, Trianel Power). Three of these power plants will have
an efficiency of 45% (one 500 MW and two 750 MW) and four of 46% (one 800 MW and
two 2 x 800 MW). [sources: Montel Powernews (2007), Reuters (2008), RWE (2008)]
4.1.2
Pulverised lignite-fired power plants
No questionnaires were submitted for lignite-fired power plants. Therefore we used public
sources for the energy-efficiency for lignite plants. Figure 24 shows the results.
50%
48%
46%
44%
42%
40%
38%
36%
34%
32%
30%
Ger many -
Ger many -
Lippendor f
Nieder aussem, Unit
BAT
Poland - Pat now 9
Germany - Boxber g Ger many - Neurat h Poland - Belchat ow
BoA II
II ( ELBIS)
2009-2010
2016
K, Cologne
2000
2003
2008
2008
2007- 2011
Figure 24 Design energy-efficiency (%) for lignite plants (sources: Power Technology (2007), Process tal k (2008), Vattenfal (2008), EBRD (2005),
DTI (2006))
The energy-efficiency of the lignite power plants for which data was found ranges from
41% to 44%, which is close to the BAT efficiency of 43%.
The power plant with 41% efficiency is a smaller plant in Poland (Patnow 9), which is currently under construction, with a capacity of 464 MW (ZEPAK, 2004). The power plant is
planned to be commissioned this year. The somewhat lower efficiency of this plant in comparison to BAT can be due to the smaller size of the plant or to the type of lignite. The
other plants all have units bigger than 800 MW.
46
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
4.1.3
IGCC plants
Figure 25 gives the data regarding energy-efficiency that was found for IGCC plants from
the questionnaires.
50%
48%
46%
44%
42%
40%
38%
36%
34%
32%
30%
BA T 2008
Coal 2011-2013
Coal 2011-2013
Lignite 2014
Figure 25 Design energy-efficiency (%) per IGC C plant
The energy-efficiency of the two planned hard coal IGCC plants is equal to BAT efficiency;
46%. The other power plant is a lignite-fired power plant with CCS, explaining the lower
efficiency of 40%.
4.1.4
Gas-fired power plants
Figure 26 gives the data regarding energy-efficiency that was found for natural gas-fired
power plants, currently in operation.
65%
60%
55%
50%
45%
0
BA 2 8
T 00
-2 8
00
8
08
20
08
20
20
08
08
20
06
20
06
20
20
06
06
20
06
20
06
20
06
20
05
20
20
02
04
20
02
20
02
20
20
01
02
20
01
20
01
20
20
20
00
40%
F i g u r e 2 6 D e s i g n e n e r g y - e f f i c i e n c y ( % ) o f r e c e n t l y b u i l t g a s - f i r e d p o w e r p l a n t 17
The energy-efficiency of recently built gas-fired power plants ranges from 47% to 58%. On
average the efficiency of recently built plants is 56%. The power plant with 51% efficiency
was commissioned in 2000. The utility mentions that this was best available technology at
the time of ordering. The power plant with 47% efficiency is a combined-cycle plant that
has the capability to use up to 40% coke oven gas and blast furnace gas as fuel input. The
maximum efficiency that can be reached in a combined-cycle designed to be able to use
different types of gas is significantly lower than a 100% natural gas combined-cycle.
17
For some power plants gross efficiency is given in the questionnaire. This is converted to net
efficiency by subtracting 2 percent points from gross efficiency. This is based on the difference in
net and gross efficiency of 7 gas-fired power plants for which net and gross efficiency was supplied
in the questionnaire.
48
JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Figure 27 gives the energy-efficiency for gas-fired power plants under construction or
planned.
65.0%
60.0%
55.0%
50.0%
45.0%
BA
T
-2
00
20 8
0
20 9
0
20 9
09
20
0
20 9
0
20 9
10
20
1
20 0
10
20
1
20 0
1
20 1
11
20
1
20 1
11
20
11
20
1
20 1
11
20
1
20 1
11
20
1
20 1
1
20 1
12
20
1
20 2 2
10 0 1
/2 3
01
20 3
16
40.0%
Figure 27 D esi gn energy-efficiency (%) of gas-fi red power plant under cons t r u c t i o n o r p l a n n e d 18
The efficiency of the gas-fired plants under construction or planned was found to range
from 56-62% and is thereby close to BAT efficiency of 59-60%. The average efficiency of
the planned plants is 58%.
The power plant with 62% efficiency is located in Switzerland and planned to be operational in 2016.
18
For some power plants gross efficiency is given in the questionnaire. This is converted to net
efficiency by subtracting 2 percent points from gross efficiency. This is based on the difference in
net and gross efficiency of 7 gas-fired power plants for which net and gross efficiency was supplied
in the questionnaire.
4.1.5
Operational energy-efficiency
This section gives figures for the difference between design energy-efficiency and operational energy-efficiency on plant level. For coal-fired power plants no information about operational efficiency is available from the questionnaires. For gas-fired power plants there is
data for 12 power plants (see table below). The difference between design and operational
efficiency was found to range from 0-4 percent points.
Ta ble 12 Difference design and operational efficiency for gas-fired power plants
Capacity
factor
Difference design
and operational
efficiency (percent
point)
Germany
85%
0.0
Spain
Austria
Spain
Spain
Luxembourg
Ireland
Spain
Spain
Italy
Spain
Spain
46%
66%
66%
0.0
1.1
1.3
1.5
1.6
2.0
2.3
2.4
2.5
3.7
3.7
Plant location
4.1.6
93%
91%
80%
92%
80%
79%
Results interviews
Below is a summary of the main results from the interviews with utilities and suppliers
Efficiency key factor influencing economics of power plant
A contact person from a planned coal-fired power plant mentions that energy-efficiency is
one of the key aspects influencing the economics of a power plant, especially with current
high energy (and CO2) prices. Suppliers for power plants base their offer therefore on
maximizing fuel efficiency.
One large power plant supplier mentions that energy efficiency nearly always pays off.
There are only a few examples of the opposite. Normally the payback time used to calculate payback of extra investment cost is calculated on a time frame of 10 years. Basically a
life cycle cost approach is normally adopted, so energy efficiency is implicitly evaluated in
the costs.
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JULY 2008
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Another power plant supplier mentions that they design power plants to maximise energy
efficiency and reduce cost of electricity (COE). Normally an indicative payback time of five
years is applied, but this is strongly influenced by raw material costs and fuel costs and
therefore differs from plant to plant. At this moment they consider coal power plants with an
efficiency of 45% (ultra supercritical coal plants) and natural gas plants with an efficiency of
58% (natural gas combined cycle (NGC) plants) to be fully commercial. These values decrease to 36% for coal power plants and 47% for NGCC when CCS is applied.
Influence utility on design efficiency of power plant
One utility mentions that coal-fired power plants are more custom-made than gas-fired
power plants, so there is more room for discussion with the supplier regarding the choice
for specific technologies. For gas-fired power plants the technology is more standard. The
supplier offers a complete package with a set efficiency. Since the efficiency is one of the
key aspects in the economics of a power plant, suppliers aim to offer power plants with a
high efficiency.
Implementing very new technology poses a risk for return on investment
A contact person from a planned gas-fired power plant mentions that a reason for them for
choosing a (slightly) lower efficiency (58-59%) than would be possible by applying latest
technology (60-61%) is a higher expected reliability of the plant. Power plants based on
very new technologies often have more down times in the beginning of operation. To secure return on investment they choose for a more reliable concept with a slightly lower efficiency then would be possible.
One power plant supplier confirms this and mentions that some companies prefer to use
well-established techniques in order to minimize their risks.
Energy-efficiency of power plant difficult to influence once it has been built
One supplier mentions that once a power plant has been built it is difficult to improve the
energy-efficiency to a large extent. Improvements of 1-2% are typically the maximum to be
achieved. Larger improvements require extensive retrofits of the installation and are
typically only economic to extend the lifetime of a power plant. Therefore it is important to
secure a high energy-efficiency in the design phase of a power plant.
Another supplier mentions that sometimes deficient maintenance can lead to a lower operational efficiency in power plants. A cost effective retrofit to the design values is possible
in many circumstances, recovering from 1 to 5 points of efficiency. In developing countries
the lack of carbon incentives and the low price of fuel make those retrofits not economic.
Fuel flexibility can be reason for lower efficiency
One utility mentions that if a combined-cycle plant should be able to operate with industrial
process gas the design energy-efficiency will be lower than with 100% natural gas.
Future developments for coal plants
A large supplier mentions that for coal-fired plants, the frontier of efficiency of is about
46%-47% with steam temperatures of 600-620 °C, with the current austenitic steel materials. Now we are moving to temperatures of 700°C which are possible with nickel based
materials. Those materials are extremely expensive, especially the turbine components.
The few achievable efficiency points expected, to raise the efficiency to 50%, can’t now
justify the higher costs of the materials. We need to develop the technologies and to have
lower raw materials prices to be economic.
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4.2
Capture-readiness
This section gives an overview of the results for capture-readiness of recently built and
planned power plants. An overview is given for gas-fired power plants (4.2.1) and for coalfired power plants (4.2.2). Section 4.2.3 gives an overview of characteristics of captureready plants based on the questionnaires. The results from the telephone interview are
given in section 4.2.4.
4.2.1
Gas-fired power plants
Few recently built and planned gas-fired power plants are found to be capture-ready. The
results from the questionnaire show that of the power plants that participated:
All 21 operational gas-fired power plants are not capture-ready.
Of the 14 gas-fired power plants under construction 1 is capture-ready.
Of the 17 planned gas-fired power plants 1 will be capture-ready.
Non-capture ready plants
The reasons mentioned by the utilities for not being capture-ready are:
“When the power plant was built, CCS was not a proven technology yet.”
“No technology was available at the moment of planning”
“Neither local geology nor local infrastructure is readily adaptable for large-scale
carbon storage.”
“Lack of an enabling and long-term regulatory framework”
“We considered CCS at an early stage and found it to be very expensive (espe-
cially with free allocation of about 90% of credits)”
“Since carbon capture technologies are more suitable and less expensive for coal
power plant they will probably not be applied to natural gas combined cycles during the lifetime of the plant. Since the CO2 concentration in the exhaust gas stream
of coal-fired plants is considerably higher and the emissions are greater, the capture cost per tonne CO2 are proportionally lower for coal plants. For this reason we
are focusing more on coal-fired power plants for CCS.”
“We have not been able to identify suitable sites for long-term storage of CO2 in
the region.”
One utility, with 5 recently built gas-fired power plants, mentions it is technically possible to
add CO2 post combustion technology to the plants. For the other power plants the option of
adding CO2 capture is un-investigated. It is expected that a certain share of these power
plants could be retrofitted with CO2 capture equipment.
Capture-ready plants
The capture-ready plant that is under construction mentions: “We have evaluated the
space requirements for an amine-based system, and rather than setting aside a specific
envelope, have satisfied ourselves that we can accommodate current technologies. Technology selection for CCGT is less clear than for conventional coal-fired plant due to issues
with amine poisoning caused by higher excess air in CCGT exhausts. Accordingly a nonspecific technology approach has been adopted so as to avoid closing out emerging capture technologies.”
The planned capture-ready power plant mentions that the plant will be made capture-ready
because they expect that future CO2 prices will be high enough to cover costs for CO2 capture. They do expect however that for coal-fired power plants it will sooner be cost-effective
to capture CO2 than for natural gas-fired power plants.
4.2.2
Coal-fired power plants
There is no information from the questionnaires for power plants in operation. After 1997, 8
coal plants have been commissioned of which 6 are lignite-fired plants. Based on public
available sources, these plants do not seem to be capture-ready.
For the power plants under construction and planned, 16 out of 60 plants participated in
the questionnaire. 13 of these plants will be capture-ready.
A contact person of a power plant currently under construction mentions that at the time of
decision, the CO2 problem was not identified deep enough. This plant will be commissioned in 2009. Two planned power plants indicate not to be capture-ready because it was
not an issue at the time the design was commenced. They mention however that enough
space seems to be available to develop the technology in the future.
For the power plants being capture-ready the main reasons mentioned are:
Future CO2 prices are expected to be sufficient to cover costs for CO2 capture
(Expected) government and EU policies
Company policy
The coal plants that participated in the questionnaire are located in Germany (3), United
Kingdom (4), the Netherlands (2), Belgium (2), Italy (2), Poland (1) and France (1).
Countries with planned coal-fired power plants which are not represented in the questionnaire are:
2 planned in Bulgaria, Romania, Greece and Czech Republic
1 planned in Portugal, Austria, Spain, Hungary, and Slovenia
It is not certain if the results from the power plants that participated in the questionnaire are
representative for the other planned coal plants. Governmental policies and local attitudes
towards CCS can differ much. Therefore the degree of capture-readiness for the other
power plants is unknown.
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In the questionnaires, one Polish plant is included. In total there are 2 power plants under
construction and 7 power plants planned in Poland. Based on telephone contact with the
utilities, most of these plants do not seem to be considering CCS at the moment.
4.2.3
Characteristics of capture-ready plants
Below is a summary of the results from the questionnaires for capture-ready plants.
Space reservation
All capture-ready plants reserve space on site for the capture equipment. Most of the pulverised coal plants reserve 2-3 ha. One IGCC plant reserves 10 ha of space.
Distance to storage site
The reported distance to the storage site ranges from 50-450 km. Most plants have a distance of 100-250 km from a storage site.
Costs
Costs are often assessed by an external party, but not in all cases. Often plants are still
investigating the different capture methods. One plant investigated cryogenic capture but
since the estimated costs are very high they are also exploring other options. Another plant
estimates the costs for capture to be between 25-50 €/tonne and 10-15 €/tonne for transport. Another utility estimates the costs for transport to be 5-9 €/tonne.
Capture technology
Often plants are still investigating capture options. Post combustion by amine scrubbing is
mentioned for four pulverised coal-fired power plants. One IGCC plant plans to use precombustion / clean shift and physical solvent with a modular approach (starting with a capture rate of approximately 50% of the syngas).
One gas-fired plant mentions they have evaluated the space requirements for an aminebased system, and rather than setting aside a specific envelope, have satisfied themselves
that they could accommodate current technologies. The reason for this is that they want to
avoid closing out emerging capture technologies, by taking a non-specific technology approach. They have the feeling that improved technologies will be developed that will be
more cost-effective than the current available technologies.
Capture-rate
In most cases the capture rate for CO2 will be 90%.
Type of reservoir
The main type of reservoirs mentioned for CO2 storage are depleted gas/oil-fields (onshore
and offshore), enhanced oil or gas recovery and deep saline aquifers.
Transport of CO2
Pipeline transport is often the preferred option for the transport of CO2 but in one case
railway transport is considered.
4.2.4
Results interviews
Below is a summary of the results from the interviews.
Costs to be capture-ready
Two utilities mention that the costs to be capture-ready are difficult to estimate. The largest
part of additional costs is the purchase of additional land. In both cases there are no preinvestments done, due to uncertainties in technologies for carbon capture that will be used.
One power plant supplier estimates extra costs to range from 5-15% of capital costs. Precombustion plants are estimated to be at the higher end of costs because not only additional space must be taken into account, but also some moderate pre-investment are
needed. This to limit the energy-efficiency drop after CO2 capture is implemented.
Retrofit of operational power plants for CCS
One large power plant supplier mentions that operational power plants can often be retrofitted with CO2 capture equipment but that it is generally not economical convenient. If
there is not sufficient space at a site or if it’s needed to reconstruct some particular equipment it can be considered as impossible in economical terms. If retroactive laws would
oblige operational plants to be retrofitted with CCS, it would therefore cause early retirement of some assets.
Another supplier examined at random a sample of six recently constructed plants and they
found that about 50% of them are not qualified to be retrofitted by CO2 capture. The reason
must be found in the plant lay-out, in the insufficient space or in the technical design. The
cost of provisions to have the right lay out to be capture ready, could be at maximum 1% of
the total cost of the plant.
A third power plant supplier estimates the extra costs to retrofit a non-capture power plant
to be in the range of 15-25% in comparison to a new power plant with CCS, depending on
the CCS rate and scheme, fuel type and power plant technology.
CCS in gas-fired power plants
One large power plant supplier advises to focus first on coal-fired plants since they are
normally run in base load, while CCS cannot modulate in the way now combined cycles
are often modulated. Moreover due to the lower carbon content of natural gas, marginal
abatement CCS additional costs are higher.
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
Building new plants on existing sites
One utility mentions that they build new plants, to replace old plants, on existing sites because of difficulties they are facing with local authorizations. This makes it more difficult to
build a capture-ready plant, because land area is fixed and distance to storage sites and
transport routes cannot be taken into account as in normal site selection. Also it is expensive to modify plant design to consider the CCS requirements.
EU policy: requirement of capture-readiness
Two utilities are in principle positive about EU policy for capture-readiness, however there
shouldn’t be detailed conditions for capture-readiness in terms of the type of preinvestments that should be done. There is too much uncertainty regarding the type of capture method that will be used. Capture-readiness should mean the availability of space for
CO2 capture and a preliminary evaluation of the feasibility of transport infrastructure and of
the availability of suitable storage sites.
EU policy: CCS obligation
The utilities mentioned that the EU (and national governments) should not obligate the use
of CCS but should make sure that the CO2 prices are high enough. Currently the CO2 price
is too low to give a proper incentive for CO2 emission reduction. Prices should be at least
40-50 €/ton.
An obligation undermines the functioning of the emissions trading scheme.
Role EU to stimulate CCS
Two utilities and two large power plant suppliers give the following advice for the role the
EU could play to stimulate the use of CCS:
• Long-term certainty is needed regarding the type of system and rules that is used
•
for emission reduction.
The EU has to define the conditions and legal framework under which CCS can be
•
applied in the European directives.
The EU should play a role in harmonizing the set up of national infrastructures for
•
CO2 transport. E.g. by setting rules for transport of CO2 across boundaries.
Within emissions trading the CO2 price must be high enough. When the prices for
CO2 are high enough (> 50 €/tone CO2), CO2 capture will happen automatically.
There also should be more certainty about the continuity of ETS after 2012 and for
•
the next 20 years.
CCS can financially be stimulated e.g. by using the income from auctioning for set-
•
ting up of infrastructures for CO2 transport.
The EU should define the funding mechanism and qualification procedure for the
•
10-12 large scale demonstration units that are needed to validate the technology.
Clear definitions should be set for capture-readiness and policy requirements in
•
this field.
Inform public on this subject. This contributes in creating good conditions for operators to do research and realize CCS power plants; this should avoid delays to
receive authorizations for realizing the plants and the related infrastructures.
5
Conclusions and recommendations
5.1
Energy-efficiency
The results from the questionnaire indicate that the majority of recently built and planned
power plants have net energy-efficiencies close to BAT level (46% hard coal, 43% lignite
and 59%-60% gas). This information is confirmed by the data for average country energyefficiencies based on IEA (2007). The countries with large shares of new capacity have
high energy-efficiencies, e.g. for gas-fired power generation, Spain and Italy with large
shares of new capacity have a gross efficiency
generation in 2005, respectively.
19
of 58% and 55% for gas-fired power
Based on interviews with utilities and suppliers we found that energy-efficiency is one of
the key aspects influencing the economics of a power plant, especially with high energy
and CO2 prices. In order therefore to ensure the use and further development of efficient
power generation technologies, high fuel and CO2 prices are therefore a key incentive.
5.2
Capture-readiness
The main results from the questionnaire are that:
•
Most recently built operational power plants have not been designed as captureready. Nevertheless some could be retrofitted with CCS.
•
Of the planned coal-fired power plants that participated in the questionnaire 13 out
of 16 will be capture-ready.
•
Of the planned gas-fired power plants only 2 out of 31 will be capture-ready.
Since a large share of new fossil capacity consists of gas-fired power plants (66%), the future share of gas-fired power generation in total fossil power generation will be large. The
future share of CO2 emissions by gas-fired power plants in total fossil plants is estimated to
be 45%20. The gas-fired power plants that will be built in the period 2010-2015 are expected to continue operation till 2040-2045. This suggests that at least a share of the gas-
19
IEA Energy Balances only give data for gross power generation, so no net efficiencies could be
calculated.
20
Based on average efficiency of 46% for new coal-fired power plants, 58% for new gas-fired
power plants, 7000 load hours for coal and 6000 for gas (based on the questionnaires)
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EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
fired power plants needs to be capture-ready in order to reach deep CO2 emission reduction targets.
Three important disadvantages of CCS at gas-fired power plants in comparison to coalfired power plants are:
• Capture costs are higher for gas-fired power plant per tonne of CO2.
•
CCS is more suitable for base-load power generation, which is more often done by
coal-fired plants than by gas-fired plants.
•
The technology selection for NGCC is less clear than for coal-fired plants due to
issues with amine poisoning caused by higher excess air in the NGCC exhausts.
In order to make CCS an option for NGCC plants, additional research is therefore needed
to solve the technological issues. Additionally, financial incentives may be needed to compensate for the higher capture price per tonne of CO2.
For coal-fired power plants, a large share of planned plants is expected be capture-ready,
mostly based on strategic decision regarding expected CO2 prices or governmental pressure. However the general attitude by governments and companies differ per country.
There still seem to be quite some planned power plants, which will not be capture-ready.
To make sure that all planned coal-fired power plants are capture-ready, clear requirements should be defined.
The main results from the interviews with utilities and suppliers are summarized below.
This gives an overview of the action the EU should take from their point of view:
•
Clear definitions should be set for capture-readiness and policy requirements in
this field.
•
No requirements should be set regarding the type of pre-investments that should
be done because there is still too much uncertainty regarding the type of capture
•
method that will be used.
In order to stimulate the use of CCS, the EU (and national governments) should
not obligate the use of CCS but should make sure that CO2 prices are high
enough. Currently the CO2 price is too low to give a proper incentive for CO2 emission reduction. Prices should be at least 40-50 €/ton. An obligation is expected to
undermine the functioning of the emissions trading scheme.
•
The EU should play a role in harmonizing the set up of national infrastructures for
CO2 transport. E.g. by setting rules for transport of CO2 across boundaries.
•
Plants at full demonstration scale are needed. The EU should support technology
developers and plant operators in financial terms to promote these experiences.
5.3
Recommendations
Fossil fuel prices and CO2 prices give a strong incentive for building energy-efficient plants.
Typically, fuel costs account for 40% of power generating costs (€/kWh) for coal-fired
power plants and 60% for gas-fired power plants (Graus and Hendriks, 2006). A CO2 price
of 20 €/tonne adds roughly 55% to power generating costs for coal and 20% to power generating costs for gas (World Nuclear Association, 2008). Therefore high CO2 and high fuel
prices are a key incentive to both implement efficient technologies as well as push technological development for further improvements. The emissions trading scheme (ETS) offers
a good policy framework for stimulating efficiency improvement. The rules applied in the
ETS should then be set in a way that CO2 prices are sufficiently high.
Regarding CCS, most operational power plants have not been designed as capture-ready.
However also many planned gas-fired power plants and a number of planned coal-fired
power plants are expected not to be designed as capture-ready. Therefore clear legislation
is needed in this field. Requirements for capture-readiness should mainly focus on sufficient available space onsite for CO2 capture equipment and a reasonable distance to storage reservoirs. Also a study is needed to assess necessary changes to the installation
when CO2 capture is added and associated costs. This is needed so that the utility can
make a balanced decision regarding doing a number of pre-investment or not. It is not advisable to set strict requirements for pre-investments to be done, since there is too much
uncertainty regarding the optimal type of capture technology to be used. Also in the field of
CO2 transport and storage, no strict requirements can be set, before the legislative framework for CO2 transport and storage is fully developed.
For CCS to be commercial, high CO2 prices are needed of more than 50 € per tonne. For
gas-fired power plants even higher prices are needed.
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References
•
Alstom (2008). Personal communication.
•
BINE,
2006,
Kraftwerke
mit
Kohlevergasung,
Projektinfo
http://www.bine.info/pdf/publikation/projekt0906internetx.pdf
•
DTI, 2006, Advanced Power Plant Using High Efficiency Boiler/Turbine – Best
Practice Brochure, Carbon Abatement Technologies Programme, January 2006,
•
http://www.berr.gov.uk/files/file30703.pdf
E.On
(2007).
(1)
09/06,
http://www.eon-
benelux.com/eonwww/publishing.nsf/Content/Nieuwe+centrale+gebaseerd+op+schonekolentechnologie_English
(2)
http://www.secinfo.com/dsVs2.uCc.d.htm
http://www.secinfo.com/dsVs2.v1an.b.htm
(3)
•
EBRD (2005). (1) http://www.ebrd.com/projects/psd/psd2005/25438.htm
http://www.ebrd.com/projects/eias/25438e.pdf
(2)
•
Eurelectric, 2007. The Role of Electricity A New Path to Secure, Competitive Energy in a Carbon-Constrained World Full report, Brussels, Belgium.
•
European Commission (EC), 2006. Reference document on best available techniques for large combustion plants.
•
Jordal, K., Anheden, M., Precombustion Capture of CO2 Opportunities and Challenges,
encapCO2,
presentation,
•
http://www.encapco2.org/news/EU_CCS_AnhedenJordal.pdf
Gibbins (2007). http://www.co2captureandstorage.info/docs/capture/H-Gibbins.pdf
•
Graus, W. and E. Worrell (2006). Comparison of efficiency fossil power generation.
Ecofys. Utrecht, The Netherlands.
•
Graus, W. and C. Hendriks (2006). Comparison of nuclear and coal-fired power
generation. Ecofys. Utrecht, The Netherlands.
•
Hannemann, 2002, V94.2 Buggenum Experience and Improved Concepts for
Syngas Applications, F. Hannemann, U. Schiffers, J. Karg, M. Kanaar, Siemens
•
AG Power Generation/Nuon, presentation, 2002
Hendriks, C., Harmelink, M., Burges, K., Ramsel, K. 2004. Power and heat production: plant developments and grid losses. Ecofys, Utrecht, Netherlands.
http://eippcb.jrc.es/pages/FAbout.htm
•
IEA (2007). Energy balances of OECD countries 1960-2005. International Energy
Agency (IEA). Paris, France.
•
IEA (2007b). Fossil fuel-fired power generation. Case studies if recently constructed coal- and gas-fired power plants. International Energy Agency (IEA).
•
Paris, France.
IEA Greenhouse Gas R&D Programme (IEA GHG, 2007), “CO2 capture ready
plants”, 2007/4, May 2007. International Energy Agency (IEA). Paris, France.
•
IEACR (2006). CleanPower5 database. IEA Clean Coal Centre. United Kingdom.http://www.iea-coal.org.uk/content/default.asp?PageId=60&LanguageId=0
•
IPPC (2005). Reference document on Best available techniques for large combustion plants. Integrated Pollution Prevention and Control (IPPC). Seville, Spain.
•
•
IPCC (2005). Special report on carbon dioxide and storage. Switzerland.
KEMA, 2004. Influence cooling water temperature on power and efficiency of a
combined cycle, coal fired and combi power plant, KEMA 50331044-KPS/TPE 031112, Ploumen, P.J., and Rijen, S.P.N. van, February 2004.
•
•
Montel Powernews (2007). Montel Powernews vol 6 no.2 march 2007
Phylipsen, G.J.M. K. Blok and E. Worrell (1998). “Benchmarking the energy efficiency of the Dutch energy-intensive industry”, A preliminary assessment of the effect on energy consumption and CO2 emissions, Department of Science, Technol-
•
ogy and Society, Utrecht University. Utrecht, The Netherlands.
Phylipsen, G.J.M., W.H.J. Graus, K. Blok, Y. Hofman, M. Voogt (2003). International Comparisons Of Energy Efficiency - Results For Iron & Steel, Cement And
Electricity Generation, Ecofys. Utrecht, The Netherlands.
•
Platts (2006). World Electric Power Plant Database (WEPP).
http://www.platts.com/infostore/product_info.php?products_id=85
•
Power Technology (2007). Sempell valves on RWE high efficiency
http://www.power-technology.com/projects/lippendorf/
•
Power Technology (2008). Futtsu combined-cycle plant, Yokohama, Japan.
http://www.power-technology.com/projects/yokohama/
•
Powerclean R, D&D Thematic framework (Powerclean and the European Union),
2004. Fossil fuel power generation: State-of-the-art.
•
Powerfuel (2008). Hatfield power
http://www.powerfuel.plc.uk/id4.html
•
•
Process talk (2008). http://www.processingtalk.com/news/tco/tco133.html
Reuters (2007). Suez's Electrabel sets Wilhemshaven for power plant. November
•
14th, 2007. http://uk.reuters.com/article/oilRpt/idUKL1414160220071114
Ruth, 2003. Advanced clean coal technology in the USA, Science Review – Mate-
•
rials at high temperatures 20(1) pp7-14, 2003
RWE (2008) http://www.rwe.com/generator.aspx/rwe-power-icw/power-plant-new-
•
build/language=en/id=502962/page.html
Sanford, L. (2007). First 60 Hz ‘H’ takes shape at Riverside. Modern Power Sys-
•
tems 27:9, p47-49 (Sep 2007).
Siemens
station
project.
April
United States.
07,
2008.
(2008)
http://w1.siemens.com/innovation/en/publikationen/publications_pof/pof_spring_20
07/technology_for_the_environment/energy_efficiency.htm
•
62
STEAG
http://www.steag.com/steagde/images/newsn12/Walsum_10_PM_EN.pdf
JULY 2008
(2008)
EFFICIENCY AND CAPTURE-READINESS NEW FOSSIL POWER PLANTS
•
Syngas Consultants (2008). European Coal Gasification Projects. February 25th
2008.
Tokyo.
http://www.rite.or.jp/Japanese/labo/choryu/workshop/futuregenws2008/2008FGWS
_MrHIGMAN.pdf
•
•
Stork (2008). Personal communication.
Tampa, 2001, Program update 2001 of Tampa Electric Integrated Gasification
•
Combined-Cycle Project – An Update, US department of Energy, 2001
Tech-wise A/S, 2003a. http://ad700.techwise.dk/annual1999.htm
•
Tech-wise A/S, 2003b. Advanced 700°C PF Power Plant, power point presentation
Tech-wise A/S, Fredericia, Denmark, May 2003
•
Vattenfal
(2008).
reports/filter.asp?filename=page_011.html
•
VGB Powertech (2004): Jahresnutzungsgrad von fossil befeuerten Kraftwerken
gemäß den „besten verfügbaren Kraftwerkstechniken“. VGB Stellungnahme. Au-
•
http://www.vattenfall.com/cs-
gust 2004
Viswanathan, 2000. Materials For Boilers In Ultra Supercritical Power Plants, R.
Viswanathan and W. T. Bakker, EPRI, in Proceedings of 2000 International Joint
Power Generation Conference, Miami Beach, Florida, July 23-26, 2000
•
Wabash, 2000, Wabash River Coal Gasification Repowering Project, Final technical report, Wabash River Energy Ltd, August 2000.
•
World Nuclear Association (2008). Breakdown of generating costs for coal, gas,
nuclear and wind. http://www.world-nuclear.org/info/inf02.html
•
ZEPAK (2004). http://www.zepak.com.pl/en/patnow
Appendix
Questionnaire energy-efficiency and CCS in new power plants
Study for European Commission
The data supplied in the questionnaire will be treated as confidential. If preferred a confidentiality agreement can be signed. A summary with the main findings of the study will be
send to you after the study is completed. An extract of the report concerning your power
plant can be send to you for your approval before submission of the report to the EU.
This study looks at gas-fired and coal-fired power plants (or units) built after 1997 and
planned power plants. Please submit one questionnaire per power plant. If the data requested in the questionnaire differs per plant unit you can submit one questionnaire per
unit.
1. General information
Company name
Plant or unit name and location
Construction year / planned to be commissioned
Status (operational, under construction, planned)
Contact person
Telephone number
Email address
Date
2. Basic plant or unit parameters
Capacity (MW e)
Fuel use (e.g. 90% coal and 10% biomass)
Turbine type (steam turbine, gas turbine, combinedcycle)
Input temperature (ºC) to turbine
Input pressure (bar) to turbine
Cooling method (cooling tower, sea-water cooling)
Typical load hours
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3. Energy-efficiency of power plant or unit
What is the design efficiency (%) of the power plant or unit, based on net calorific
value, measured as net output at the generator? See further appendix for definition
of efficiency.
.........
In case the design efficiency differs significantly from “Best available techniques”
(BAT) efficiency (see table below) can you give the main reasons for this (e.g. financial or technical considerations)?
.........
Figure 28 Best available techniques (BAT) for power plants
Technology
Fuel
Energyefficiency
Pulverised coal steam cycle (ultra-supercritical)
Coal
46%
Lignite
43%
Coal gasification combined cycle (IGCC)
Coal
46%
Natural gas combined cycle (NGCC)
Natural gas
59%
In case the power plant is operational, please give the yearly average operational
efficiency (%) of the power plant or unit for the last three years in the table below.
The method for calculating the energy efficiency can be found in the appendix.
Year: 2005
Year: 2006
Year: 2007
In case the operational efficiency differs widely from the design efficiency of the plant
can you give the main reasons for this (e.g. full load hours, climate conditions, etc)?
...
4. Carbon capture readiness of power plant
Has the option of capture and storage of CO2 (CCS) been assessed for the power
plant? If yes continue with questions below. If no, please give the reason for this.
...
Can you give an indication regarding the amount of space that has been reserved on
site for applicable capture installations?
...
What other considerations have been assessed for CCS (capture technology to be
used, etc.)?
...
What is (will be) the annual amount of CO2 produced in your plant
...
What is the envisaged capture rate once CCS is in place:
…
Which storage sites for CO2 have been considered?
...
What is the distance of the storage sites to the plant?
...
Can you explain how the CO2 transport would be arranged (pipeline infrastructure to
be build, other transport options)?
...
Can you give information about costs that have been assessed for CCS?
* Investment (retrofit) cost: from € … to …
* Operational Cost:
Cost per ton of CO2 captured: …. € / ton
Transport and storage cost per ton CO2: … € / ton
Have the costs been assessed by an external party?
...
Comments and suggestions as well as other relevant information are welcome in the
text box below.
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Thank you for your co-operation.
You can send this questionnaire to Wina Graus by e-mail ([email protected]), fax
(+31302808301), phone (+31302808321) or post mail:
Ecofys Netherlands bv
Att: Wina Graus
P.O. Box 8408
3503 RK Utrecht
Netherlands
Appendix
Definition of energy-efficiency
The formula for calculating the energy efficiency (η) of a power plant is given below:
η = P / I.
Where:
• η=
Energy-efficiency for power generation at plant or unit
• P =
• I=
Power production from power plant, measured as net output at the generator
Fuel input for power plant, based on net calorific value (NCV)21
Combined-cycle
In case of a combined-cycle please submit design efficiencies for the plant or unit as a total
and if available indicate the design efficiency of the gas turbine.
Combined heat and power plant (CHP)
In case of heat extraction the heat efficiency should also be supplied. The heat efficiency is
defined as:
η (heat) = H / I.
Where:
• ηheat = Energy-efficiency for heat plant or unit
• H = Heat output from power plant
• I=
Fuel input for power plant, based on net calorific value (NCV)
21
The Net Calorific Value (NCV) or Lower Heating Value (LHV) refers to the quantity of heat liberated by the complete combustion of a unit of fuel when the water produced is assumed to remain
as a vapour and the heat is not recovered. Conversion factors used in this study for converting
from gross calorific value (GCV) to net calorific value (NCV) are 0.9 for natural gas, 0.93 for oil and
0.97 for coal.
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Telephone interview
CCS
Planned power plants
For capture ready plants: Why are they capture ready, even if there is no legislation yet? How much extra does it cost to be capture ready?
For plants not capture ready: Why are they not capture ready? Can they be retrofitted with CCS? What would be the costs?
Operational power plants
Can they be retrofitted with CCS? At what costs?
All power plants
Do you think CCS should play a key role in reducing greenhouse gas emissions?
What role should the EU play (what kind of actions do you expect from the EU) in
stimulating the use of CCS?
What do you think about upcoming EU legislation that will require new fossil fuel
plants to be CCS-ready, but without imposing an obligation to install CCS by a cer-
tain date.
What do you think about introducing a CCS obligation which will require:
(1) New fossil fuel plants authorized after 2015 to be CCS-equipped and
(2) existing fossil power plants be retrofitted with CSS by 2025.
Does the ETS scheme work well to reduce greenhouse gas emission in the power
sector? Would there be more efficient options to reduce emissions?
What prices for emission allowances do you expect for the third ETS phase (full
auctioning). Will the carbon prices in the third phase of the ETS scheme be suffi-
cient to cover the additional costs of CCS?
Do you have an idea about expected additional costs for your power plant per year
once full auctioning will apply within the third ETS phase?
Energy-efficiency
What role did energy-efficiency play in the design process of your power plant?
Was energy-efficiency specifically looked at? Was there a trade-off between energy-efficiency and extra capital costs? Is a certain payback time used to calculate
payback of extra investment costs for a more efficient plant?
For plants below BAT energy-efficiency: Why did they choose less efficient technology?
For plants at BAT energy-efficiency: What were the options considered when designing the plant? Why did they choose efficient technology?
(for operational power plants) In case operational efficiency is much lower than
design efficiency. What are the reasons for this?
What do you think about the current IPPC directive? Does the IPPC Directive
mechanism provide for further improvement of energy efficiency? What do you
think about the proposal to make BAT as described in BREFs binding for new
plants?
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