COMPARISON OF CARBON CAPTURE AND STORAGE WITH
RENEWABLE ENERGY TECHNOLOGIES IN THE YEAR 2020
BY WAY OF A LIFE CYCLE AND A COST ASSESSMENT
Peter Viebahn, Joachim Nitsch (Deutsches Zentrum für Luft- und Raumfahrt)
Manfred Fischedick (Wuppertal-Institut für Klima, Umwelt, Energie)
ABSTRACT
· To use coal and natural gas in a more environmentally-friendly way, the option
of "carbon capture and storage" (CCS) is discussed,
· a first system-analytic view in the form of a life cycle and a cost assessment and
a comparison with renewable energies was done regarding future conditions in
the power market (2020),
· the results show that a realistic CO2 emissions' capture rate of 88 % at the
power plant results in a reduction of greenhouse gases by only 65 %,
· renewables will be competitive with electricity from CCS power plants from the
beginning of CCS technology in 2020.
·
1000
Power plant
Pulverised Hardcoal
eta: 49% -> 40% / 38%
Sequestration and Liquefaction
Pulverised Lignite
eta: 46% -> 34%
NGCC
eta: 60% -> 51%
· Coal is the most abundant fossil fuel. Therefore the question arises how coal can
be used in a more environmentally-friendly way to meet the international
greenhouse gas reduction goals,
· the option of "carbon capture and storage" (CCS) is discussed, that means the
capture of the CO2 at the power plant, its liquefaction, transport, and storage in
the underground,
· CCS requires a high energy consumption; levelised electricity costs are expected
to increase by 50 %.
METHODS
· Ecology: LCA according to ISO 14.040ff., modelled via a material flow
network,using the "UBA-method of impact categories" (German Env. Authority)
· Economy: Experience curves and learning rates,
· CCS technologies: post-combustion, pre-combustion, and oxyfuel with data
from the industry,
· "Future situation": Higher efficiency and sensitivity analyses for hard coal
methan emissions, CO2-capture rate, operation materials, leackage rates.
Figure: Schüwer
Storage
Wind Solarthermal
900
800
700
600
-79%
-68%
500
-78%
-65%
400
300
-65%
Fossil fired power plants in 2020
· Location: Ruhrgebiet (western part of Germany),
· transportation of the CO2 via a pipeline from the Ruhrgebiet to
Northern Germany (empty natural gas fields) over 300 km,
· CO2-capture rate at the power plant of 88 % (oxyfuel: 99.5 %),
· no leakage rate of the storage,
· using higher efficiencies considered to be possible for 2020.
100
0
PC
PC + CCS
PC +
Oxyfuel +
CCS
PC
PC + CCS
NGCC
NGCC +
CCS
Power Plant
Fuel
Capture method
Pulverized Coal
Hard coal
Pulverized Coal
Pulverized Coal
Hard coal
Lignite
Integrated Gasification combined
cycle (IGCC)
Natural gas combined cycle (NGCC)
Natural Gas
Chemical scrubber
(MEA)
Oxyfuel
Chemical scrubber
(MEA)
Physical absorption
(Rectisol)
Chemical scrubber
(MEA)
Hard coal
Decrease of
Efficiency
49% > 40%
IGCC + CCS
Wind Solarthermal
(2) Further impact categories
· The impact indicators increase by 37 % to 96 % in the case of a pulverised coal
power plant,
· the increase of about 40 percentage points is caused by the higher energy
resource consumption (+34 %) as well as through the additonal energy used for
transport and storage,
· the photo-oxidant formation increases much above average (+ 96%) due to the
production of the solvent monoethanolamine (MEA) used for scrubbing.
Fuel supply
0.15
Photo-oxidant
formation
[g Ethen eq/kWh,el]
Power plant
Sequestration and Liquefaction
Acidification
[10*g SO2-eq/kWh,el]
Eutrophication
[g PO 4-eq/kWh,el]
Transport
Storage
PM10-Equivalents
[10*g PM10eq/ kWh,el]
Cum.EnergyDem.
0.12
+ 39%
+ 37%
0.09
+ 44%
0.06
+ 96%
+ 38%
0.00
PC
49% > 38%
46% > 34%
IGCC
Greenhouse gas emissions (CO2 and methane) for fossil fired power plants compared with renewable energies
0.03
Figure: Photo Disc
Transport
IGCC (Hardcoal)
eta: 50% -> 42%
200
INTRODUCTION
Figure: Photo Disc
Fuel supply
g CO2-eq / kWh,el
PC and
CCS
PC
PC and
CCS
PC
PC and
CCS
PC
PC and
CCS
PC
PC and
CCS
Further impact categories illustrated by way of a hard coal fired pulverized coal power plant
50% > 42%
60% > 51%
Renewable power plants in 2020
· Location: wind offshore power plants in the North Sea and solar
thermal power plants in North Africa,
· electricity transport via high voltage direct current lines (HVDC) to
the Ruhrgebiet.
(3) Electricity production costs
· Both CO2 penalties for coal and natural gas and increasing prices of natural gas
increase the levelised fossil electricity costs to 6.5 - 7 Eurocent/kWh until 2050,
· in addition, CCS technologies increase the electricity costs by about 50%,
· keeping the dynamic development in the past the renewable power plants can
decrease their levelised electricity costs from 12-13 Eurocent/kWh today to 6
Eurocent/kWh until 2050.
This means, renewables will be competitive with electricity from CCS power plants
from the beginning of CCS technology in 2020.
RESULTS AND DISCUSSION
NGCC, low price
NGCC + CCS, low price
wind-offshore
(1) Greenhouse gas emissions
PC (coal), low price
IGCC (coal) + CCS, low price
renewable mix
NGCC, high price
NGCC + CCS, high price
PC (coal), high price
IGCC (coal) + CCS, high price
14
Therefore it does not seem justified to talk about "CO2-free" fossil power plants to
reduce the greenhouse effect in a sustainable manner.
12
levelized electricity costs ct(EUR) / kWh,el
· capture, transport, and storage of CO2 require 23 % - 40 % more energy,
· CO2 and methane are emitted also in the preprocesses (mining industry,
transport),
· the greenhouse gas emissions in total are reduced by only 65 % to 79 %,
· renewable electricity causes only 2 % of the fossil fired power plant’s
greenhouse gas emissions,
· the cleanest power plant without CCS (natural gas combined cycle) causes only
45 % more emissions (400 g CO2-equ./kWh) than the worst power plant with
CCS (pulverized hard coal with 274 g CO2-equ./kWh).
10
including CCS
8
6
without CCS
4
two fuel price developments
2
0
2000
2005
2010
Institute of Technical Thermodynamics
Contact: [email protected]
2020
2030
2040
2050
Levelised electricity costs - comparison between “CO2-free” fossil power plants and renewable power plants between
2020 and 2050 (each with low and high development of fossil fuel prices)
A research project in co-operation with