A Life Cycle Analysis of Electricity Generation Technologies Health and Environmental Implications of Alternative Fuels and Technologies

A Life Cycle Analysis of Electricity Generation Technologies:
Health and Environmental Implications of Alternative Fuels and Technologies

Joule Bergerson & Lester Lave
Carnegie Mellon Electricity Industry Center
September 2002
Contact Lester Lave: 412-268-8837 or


Abstract
Increases in electricity demand and the retirement of old generating plants necessitate investment
in new generation. Increasingly stringent environmental regulations, together with other
regulatory requirements and uncertainty over future fuel prices, make the choice of a fuel and
technology a difficult decision. We review studies examining the life cycle environmental
implications of each fuel and technology. We focus on the coal fuel cycle for several reasons: (1)
More than half of the electricity generated in the USA uses coal as the fuel, (2) historically, the
coal fuel cycle has been highly damaging to the environment and to health. (3) There are huge
coal reserves in the USA, China, and Russia. The fuel is inexpensive to mine and likely to be
used in large quantities in the future. First, we examine the methods for life cycle analysis. We
then present a brief historical overview of the research studies. Finally, we review and critique
the alternative methods used for life cycle analysis. Our focus is the recent studies of the health
and environmental implications of each technology. The studies agree that coal mining,
transport, and combustion pose the greatest health and environmental costs. Among fossil fuel
fired generators, natural gas power turbines are the most benign technology. Light water nuclear
reactors received a great deal of attention in the early literature, but are neglected in recent
studies. The earlier studies found that the health and environmental costs of light water reactors
were low, at least for the portions of the fuel cycle that were evaluated. The studies did not
evaluate the disposal of spent fuel and so are incomplete. Recent advances in life cycle analysis
offer a large improvement over the methods of three decades ago and should help in choosing
among fuels and technologies as well as modifying designs and practices to lower the health and
environmental costs.

2


Contents
1.
2.
3.
4.
5.
6.

Introduction………………………………………………4
Methods/Analytical Tools……………………………….9
Historical Review……..…………………………………5
Overview of Principal Studies…………………………..5
Boundaries………………………………………………11
Coal………………………...……………………………12
6.1 Power Plant Characteristics……………………….13
6.2 Mining…...………………………………………….17
6.3 Processing…………………………………………..19
6.4 Composition…...……………………………………20
6.5 Transportation……………………………………..20
6.6 Generation………………………………………….23
6.7 Transmission……………………………………….24
6.8 Resources…………………………………………...24
6.9 Emissions…...………………………………………25
6.10 Impacts……...……………………………………..27
6.11 Data Sources………………………….…………...28
6.12 Summary of Results…...……………...…………..30

7. Other Fuel Cycles……………………………………….38
7.1 Natural Gas…………..……………………………40
7.2 Hydro...……………………...……………………...43
7.3 Oil..…………………………………………………45
7.4 Nuclear…………………………………………..…47
7.5 Biomass…………………………………………….48
7.6 Wind………………………………………………..50
7.7 Solar………………………………………………..51
8. Conclusions……………………………………………..53
9. References………………………………………………54
10. Appendix…………………...…………………………...59

3


1. Introduction
Two important and controversial issues are reshaping the electricity industry. First, the business
side of the industry is being turned upside down by “deregulation.” Deregulation is a misnomer
since the extent of regulation is not lessening to any great extent, but the nature of the regulation
is changing in fundamental ways. Generators must decide which plants to build and operate
without any assurance that they will receive a return on their investment. Second,
environmental regulations are becoming significantly more stringent, with the prospect of
stringent regulation of carbon dioxide. Much more stringent regulation of SOx and NOx results
from PM2.5 and ozone standards; mercury discharge standards and perhaps stringent discharge
standards for other heavy metals will be costly. While the USA has not agreed, even in principle,
to reduce the emissions of greenhouse gases, we judge stringent standards to be likely in the next
decade.
These issues might be minor, or even academic issues save for the fact that generation owners
are faced with decisions about major investments to prolong the lives of current facilities as well
as the need to invest in new capacity to meet increasing demand and the retirement of old plants.

Current environmental regulations are known, but new regulations follow the advance in
scientific knowledge, e.g., PM2.5, or a reinterpretation of the data, e.g., mercury. The best way
of anticipating future regulations is to do the best analysis of the full range of environmental
discharges and their implications. Isn’t this also the best way to help shape or influence good
policy? Thus, to make informed decisions, investors need to know the life cycle health and
environmental implications of the range of fuels and generation technologies that are available
now or will be available shortly. Unfortunately, the life cycle implications cannot be known with
certainty now. However, uncertainty about the implications and each fuel and technology can be
reduced by a careful application of current methods.
A generation shortage would be costly to society. First, almost every part of our daily lives
requires electricity, from heating and cooling our residences and work places to powering
electronics, to lighting, to mass transit. Second, electricity is different from other energy forms
in that a shortage of generation means that everyone, or at least a large segment of the
population, would have no access to electricity. If there is a 10% shortage of gasoline, 90% of
the demand can be served. For electricity, supply and demand must balance at each instant. If
there is a tiny excess demand, voltage sags. If demand outstrips supply by more than a tiny
amount, the whole system fails, cutting electricity delivery to everyone. If action is taken
quickly, a neighborhood could be blacked out, allowing the other customers to continue having
access to electricity. However, those in the blacked out area would have no access to electricity.
California experienced electricity shortages in 2001, resulting in rolling blackouts. When the

4


traffic lights lost power in San Francisco or other large cities, traffic ceased to flow. The point is
that an electricity shortage is costly to society.
We begin with an examination of the methods for life cycle analysis. The methods have
improved substantially since the first electricity life cycle studies of the 1970s. Then, we present
a brief historical account of the research literature. We focus on the coal fuel cycle since 52% of
electricity in the US is generated by burning coal. (should the 3 reasons you state earlier not be

restated here?) Following this overview, we review of the methods and analytical issues for life
cycle analysis. Then we present a more extensive review of the modern studies done in the USA,
focusing on coal and then treating the other available fuels. Finally, we offer some concluding
remarks.
2. Methods for Life Cycle Analysis
Life cycle analysis is undertaken to inform decision makers and help them choose among
alternative fuels and technologies for electricity generation. An informed choice requires
examination of the full cycle, from fuel extraction to transport, generation, and post generation
activities. This includes an examination of the investments required for these activities. The
analysis must also include the occupational and public health burden of disease and trauma as
well as the impacts on the environment of these activities.
Modern LCA is divided into four phases: Scoping, discharge inventory, impacts, and
improvement (EPA Ref). A comprehensive analysis is impossible: It is not possible to examine
the health, energy, materials, and environmental impacts associated with each direct and indirect
aspect of each part of the life cycle. Thus, each analysis must decide, explicitly or implicitly
what will be considered in the analysis and what will be omitted.
The first LCAs (should we call these studies LCA’s?-perhaps qualify the use of the term here?)
focused on the generation and extraction stages, sometimes examining transport. They ignored
the construction of facilities and other investments (add specific other investments that were
ignored). Rather, they focused on direct implications, such as occupational deaths and disease
and public health effects from emissions of air pollution and ionizing radiation. Even here, the
studies were pushing current knowledge since the effects of current ambient levels of air
pollution and ionizing radiation were not known with confidence.
LCA was developed and formalized in the 1990s as the demand for the life cycle implications of
a variety of products, from paper cups to automobiles drew public attention. EPA and the
Society of Environmental Toxicologists and Chemists (SETAC) developed and formalized
methods for conducting the analysis. The method drew from the LCA of energy and formalized
them using the approach of chemical engineering: Conducting mass and energy balances of each
phase of the analysis. Perhaps the principal contribution of the product analyses was getting
people to think about the whole life cycle. The quantitative estimates are uncertain and subject

to controversy. The results can change depending on how the scope is changed. Given the
difficulty of conducting many energy and materials balances, the scope of the studies has to be
tightly drawn and often the balances are not highly detailed. The analyses have been found to be
time consuming and expensive.

5


Precisely the same difficulties have appeared in the LCA for electricity technologies. In
particular, Holdren (1978) was critical of other studies for not including all the important aspects
and for taking insufficient care.
A new approach to LCA was developed using the national Input-Output table1 (Lave ,
Hendrickson , … Do you consider this reference to be the best representation of eiolca?). The
advantage of this approach is that it is quick and inexpensive. The disadvantage is that it is at an
aggregate level. In particular, the US analysis is done for the 500 sector US input-output matrix.
We now turn to a brief review of published studies.
3. Brief Historical Review
The first examination of the life cycle of electricity generation begins in the early 1970s with
parallel investigations by Lave and Freeburg (1972, 1973) and Leonard Sagan (1973, 1974).
The former resulted from a Sierra Club invitation to help them develop an environmental policy
on the most desirable fuel and technology for electricity generation. The latter was an Electric
Power Research Institute study to help utilities select new generators.
The results of the two were generally similar. They focused on existing plants, rather than the
potential of new plants and new technologies. Existing plants provide data on their current
operation; little more than guesses are possible for the implications of new plants and new
technologies. Both studies examined the environmental discharges from each process and
attempted to quantify the extent of occupational and public illness and injury. They used existing
studies of the effects of air pollution (such as Lave and Seskin, 1970) and ionizing radiation to
estimate the number of cancers that would result from exposure to pollutants and radionuclides.
Lave and Freeburg emphasize the morbidity and mortality burden from burning coal. Sagan

emphasizes the large number of public deaths from transporting coal by railroad.
Both studies found large environmental and health burdens from mining, transporting, and
burning coal. Both found that oil and natural gas have much smaller environmental and health
costs. Finally, both found that light water reactors have an even lower health burden, although
neither could assess the environmental and health burdens of dealing with spent fuel or
decommissioning old reactors. (stated below?)
Sagan translated the health burdens into dollar terms, assuming that a premature death costs
society $300,000. He found that coal had larger health costs ($1.2 million) than nuclear
($210,000).
These studies opened the field and ranked the fuels in an order that has stood up over time.
However, both were incomplete in evaluating all of the aspects of the fuel cycle and neither was
able to quantify the environmental effects.
1

Hendrickson, C., A. Horvath, S. Joshi and L.B. Lave, "Economic Input-Output Models for Environmental Life
Cycle Analysis," Environmental Science & Technology, April, 1998, Vol, 32. Iss, 7. pp. 184 A-191 A.

6


Morgan, Barkovich and Meier (1973)2 evaluated the social costs associated with producing
electricity from coal. This paper focuses the evaluation of the costs to society from the activities
required to extract and burn coal to produce electricity. Although this study does not include
stages such as transportation, transmission and waste disposal for this fuel, it has identified some
important aspects to be considered in each of the categories that were considered. Within the
extraction phase, the following factors were considered: land use, mining (including acid mine
drainage, subsidence and coal refuse pile hazards), health and safety issues (black lung, mine
accidents). In the generation phase the four pollutants most harmful to humans from electricity
production from coal (still considered to be today) were evaluated. These are SOx, NOx,
particulate matter and heavy metals such as mercury. The pollutants that were not considered in

this study were CO2, heat dissipation and the global impacts of particulate matter and NOx.
These aspects of the 2 phases considered as well as the other phases involved in electricity
production from coal would need to be included in order to produce a complete LCA.
Soon after the publication of these studies, several studies were published in the first volume of
the Annual Review of Energy. Lave and Silverman (1976) review the economics of
environmental pollution beginning with a discussion of neoclassical economic theory. A
competitive market is efficient under assumptions that each firm is a price taker (no market
power) and no externalities. Clearly, the US economy in 1976 had important externalities,
especially in the production and use of energy generally and electricity in particular. If these
externalities are not treated, competitive markets will come to inefficient outcomes, e.g., the
terrible air and water pollution in Pittsburgh in 1945. However, if the externalities are
internalized by regulation or effluent fees, free markets will produce efficient outcomes. They
also discuss the application of various tools to assess the economics of environmental pollution
including benefit-cost analysis, input-output analysis and the materials balance model. The
approaches to environmental management include setting standards, effluent fees, or capping
total discharges and allowing firms to trade "allowances."
The resources that were included in the first edition of the Annual Review of Energy include
coal, nuclear, solar, geothermal, oil shale, nuclear fusion, waster materials, and hydrogen energy.
The technologies included clean liquids and gaseous fuels from coal as well as energy storage
and advanced energy conversion. This list excluded the discussion of natural gas. It was
generally believed at the time that natural gas reserves available would inhibit this fuel form
becoming a significant fraction of electricity capacity in the United States. Natural gas is
currently used to generate approximately 14%3 of the electricity in the US. This implies that this
assumption is no longer valid.
2

Morgan, M.G. Barkovich, B.R. Meier, A.K. The Social Costs of Producing Electric Power from Coal: A FirstOrder Calculation. Proceedings of the IEEE. Vol. 61. No. 10. pp. 1431-1442. Oct. 1973.
3

EIA-DOE. Table 2. U.S. Electric Power Industry Summary Statistics. Electric Power Monthly.

Viewed Sept. 10, 2002.

7


Zebroski and Levenson (1976) make one of the first attempts at a nuclear fuel cycle analysis 4.
Much of this paper is dedicated to discussing the performance of light-water reactors including
issues affecting the efficiency of the reactors as well as possible remedies. In the discussion of
the incremental costs associated with nuclear power generation they conclude that the shipping,
reprocessing, and waste disposal costs were only estimated to be 6% of the total cost of nuclear
fuel. The reprocessing of plutonium is no longer conducted in the US and the environmental
impacts involved with reprocessing are actually much greater than mentioned in this paper. The
entire discussion of reprocessing, recycling, spent fuel storage and radioactive waste disposal
would have to be revisited in light of developments in the nuclear power industry since this paper
was written. The details of the cost estimates were not discussed but an incremental cost
advantage for nuclear over coal was concluded. They estimated that the cost of nuclear was only
20% of the cost of coal and they estimated that this advantage would increase in the future. The
study shows that the capital costs of nuclear plants are higher than coal but they noted a decrease
and predicted a future decrease in this cost advantage. The true cost of nuclear fuel is still
unknown however, the capital costs of nuclear power still exceed coal power plants.
Morse and Simmons (1976) review the various solar technologies and applications being
developed at the time for feasibility and preparedness for large scale implementation5. They
included solar thermal conversion, photovoltaic conversion, production of fuels, wind energy,
and ocean thermal conversion in their discussion. This paper measured and compared the cost
effectiveness of each of these technologies. These calculations attempted to account for the fact
that in the future these technologies would become cheaper due to mass production,
technological improvement etc. While the authors suggest that the full environmental
consequences had to be examined and that the upstream impacts also needed to be considered,
they neglected to do so in much of their evaluation. They suggest that the use of gallium in the
solar technology industry would be a substantial part of the cost of solar energy but would also

have the economic effect of driving the price of gallium up for other industries. However, this
4

Zebroski, E. Levenson, M. The Nuclear Fuel Cycle. Annual Review of Energy. Vol. 1. pp. 101-130. 1976.

5

Morse, F.H. Simmons, M.K. Solar Energy. Annual Review of Energy. Vol. 1. pp. 131-158. 1976.

8


study neglects to include the environmental impacts of extracting, processing and use of the
gallium. This would be required in evaluating the true environmental implications as suggested
in this paper and this impact is significant. They suggest that the energy requirement would also
have to be addressed as this would be one of the largest material requirements, however, they
discuss this in economic terms and not in terms of environmental impact. They did rightly
conclude, however, that solar energy would not make up a large portion of energy capacity in the
US before 1985.
Kruger (1976) investigated the potential for geothermal energy6. This paper suggested that there
is great potential for geothermal energy primarily for generating electric power. However, in
2001 geothermal power only accounted for .6% of the total US electric power generation. While
the environmental impacts were identified as gaseous emissions, liquid waste disposal, and
geophysical effects such as seismicity and subsidence, there was no attempt made to quantify or
compare these impacts.
Rattien and Eaton (1976) looked at the potential for oil shale 7. Numerous serious environmental
impacts are identified in this discussion and the technologies discussed that have feasibility do
not consider electric generation potential. Petroleum in general produces very little (5%) of the
US electricity capacity today.
Post (1976) discusses nuclear fusion, its potential as well as potential environmental impacts 8.

This paper focuses on the science and technologies that could be possible in the future including
techniques for “the conversion of fusion plasma energy directly into electricity without the use of
a heat cycle”. They identify that like current fission plants, this process will involve hazardous
radiation but they still conclude that “it appears likely that fusion reactors, particularly as they
evolve, will present a smaller hazard to man and to the environment than any other major power
source with the exception of solar power”. This is contrary to current evaluations of the impact
of radiation and catastrophic possibilities.
6

Kruger, P. Geothermal Energy. Annual Review of Energy. Vol. 1. pp. 159-182. 1976.
Rattien, S. Eaton, D. Oil Shale: The Prospects and Problems of an Emerging Energy Industry. Annual Review of
Energy. Vol. 1. pp. 183-212. 1976.
8
Post, R.F. Nuclear Fusion. Annual Review of Energy. Vol. 1. pp. 213-255. 1976.
7

9


Golueke and McGauhey (1976) discuss the use of waste materials as a possible energy source9.
They investigate the potential sources and uses for energy generated from waste. However, very
few of these technologies have been implemented on a large scale. In addition, this paper
neglects to investigate the environmental implications of generating the energy using the
methods described in the paper.
Gregory and Pangborn (1976) discuss hydrogen energy as an alternative to electricity in various
applications10. These include industrial feedstocks, industrial fuel, residential appliances, and
catalytic combustion. They also suggest that hydrogen could be used as a fuel for electricity
generation but state that the high cost of hydrogen will likely make its use in this manner
unattractive.
Kalhammer and Schneider (1976) state that “energy storage can improve the operation and

economics of electric power systems”11. They discuss the potential technologies for doing this.
Somers and Berg (1976) discuss advanced energy conversion12. The main premise of this paper
is that the generation of electricity will shift to prominently be done using coal and nuclear in the
future and therefore, a stress on increasing the efficiency of these power plants will be eminent.
They suggest that this will be addressed by using advanced energy conversion to convert the
waste heat from steam and gas turbines to electricity. The combined-cycle gas–turbine power
plant is a good example of something that has been implemented today. However fuel cells have
yet to realize this same success. Although this still has potential today, it has been suggested that
this might not be the most efficient use of the waste heat. There might be a greater gain made if
the waste heat was used for heating the buildings near the power plant etc.

9

Golueke, C.G., McGauhey, P.H. Waste Materials. Annual Review of Energy. Vol. 1. pp. 257 – 277. 1976.
Gregory, D.P. Pangborn, J.B. Hydrogen Energy. Annual Review of Energy. Vol. 1. pp. 79-310. 1976.
11
Kalhammer, F.R. Schneider, T.R. Energy Storage. Annual Review of Energy. Vol. 1. pp. 311-343. 1976.
12
Somers, E.V. Berg, D. Fickett, A.P. Advanced Energy Conversion. Annual Review of Energy. Vol. 1. pp. 345 –
389. 1976.
10

10


Budnitz and Holdren (1976) present their life cycle analysis of fuels. They stress the large
amount of data and knowledge required to assess each technology. They don't attempt to
quantify the environmental or health effects of the various fuels and technologies.
Comar and Sagan (1976) update Sagan's work. Their Table 3 summarizes the number of
occupational and public premature deaths expected from the operation of a 1,000 megawatt

electricity plant for a year. They estimate the number of 2-116 for coal, 1.1-110 for oil, 0.0570.28 for natural gas, and 0.11-1.0 for nuclear. For coal and oil, the largest contributor, and largest
uncertainty, is air pollution from the combustion phase. In this analysis, natural gas is the winner
and coal continues to be the worst.
Morris (1976) focused on the f environmental impact of new energy technologies. The
environmental effect of fossil fuels was emphasized. These studies focused on the development
of the framework as well as the effects like climate, air and water quality and land.
Weills (1976) assessed the impacts of the coal fuel cycle in power generation. This paper used
1970 as a baseline and predicted up to 199013. This paper attempted to predict technology
innovations, electricity demand, and demand for coal from various locations (e.g. increasing use
of low-sulfur coal from the Powder River Basin). The impacts of these potential trends were also
predicted and estimated.
Holdren (1978) published a more comprehensive study, revisiting conventional fuels and
extending the analysis to renewable fuels: solar and biomass 14. This study was extremely
elaborate in terms of the details of the fuel cycle that were considered. Holdren was critical of
previous work in the field stating that “the inadequacies range the entire spectrum of analytical
tools: the criteria and indices by which impacts are judged and compared are under dispute; the
methods for quantifying impacts and costs are in many instances poorly developed or seriously
flawed; and the inability to compare apples and oranges makes the final goal unattainable in
many (perhaps all) important situations”. Holdren also stressed the fact that no existing or
proposed energy technology is so free of environmental problems that one would definitely be
chosen above all others.
Holdren, Morris and Mintzer (1980) developed the analysis of solar, wind, hydro, and biomass,
examining the potential environmental effects of these technologies. This paper reviewed land
use, water use, materials used for construction of energy facilities, occupational effect of energy
production, occupational deaths, injuries and illnesses from materials acquisition, public risk
from accidents and emissions, as well as ecosystem effects. This study points out that energy
conservation has varying environmental impacts.

13

Weills, J.T. Impacts of the Coal Fuel Cycle in Power Generation. Energy and the Environment: Cost-Benefit
Analysis, Proceedings of a Conference. Geological Survey of Canada. Atlanta, GA, USA. pp. 297-317. 1976.
14
Holdren, J.P. Coal in Context: Its Role in the National Energy Future. Houston Law Review. Vol. 15. No. 5.
July 1978.

11


Inhaber (1980) published several comparisons of risk of various electrical energy sources151617.
He compared the human health risks of 5 “conventional” (coal, oil, natural gas, nuclear and
hydroelectricity) and 6 “non-conventional” (solar thermal electric, solar photovoltaic, solar space
heating, methanol, wind, and ocean thermal) fuel sources. This paper concluded that the risks
from non-conventional sources can be as high or higher than those from conventional sources
when the comparison was done on a per unit of energy basis. This paper dedicated a significant
portion to the risk associated with material acquisition and man hours for construction for each
type of power plant. As part of the results of this paper, a table was presented which showed the
proportion of total man-days lost due to each source of risk for each fuel type. These risk
sources included waste management, energy backup, energy storage, emissions from material
acquisition, transportation, electricity production, or operation and maintenance, gathering and
handling fuels, or material acquisition and construction. This piece was highly criticized by
Holdren for the issues discussed above.
Bjork and Rasmussen (1999) examined a cogeneration plant supplying district heating to a
neighborhood in Sweden. This study found that the amount of environmental benefit depended
on how emissions were estimated. This study also looked at the use of trees, land filling of the
ash etc. as well as the use of non-contaminated ash as fertilizer.
Bolin (1977, 1980) focused on climate change when studying the effect of production and use of
energy181920. Smil (2000) reviewed energy production and consumption around the world21.
Tsoulfanidis (1981) examined coal, fission and fusion power plants22. He uses net energy to
estimate the energy consumed in each stage of energy production from these three power plants

in an attempt to calculate the net energy produced from each fuel type. This appears to be the
first analysis of a fusion plant. Instead of translating all environmental impacts into costs and
comparing the results, this study looked at all the phases of the cycle and calculated the total
amount of energy consumed at each of these stages. The net energy produced from each fuel
type was then compared. This study found that all three types of power plants considered
15

Inhaber, H. Comparison of Risk of Various Electrical Energy Sources. Thermal Reactor Safety: Proceedings of
the American Nuclear Society/European Nuclear Society Topical Meeting, April 6-9, 1980, Knoxville, Tennessee.
pp. 356-362. 1980.
16
Inhaber, H. Risk of Energy Production. Rep. AECB 1119. Ottawa, Ontario: Atomic Energy Control Board of
Canada. 1978. pp. 356-362.
17
Inhaber, H. Risk with Energy from Conventional and Non-Conventional Sources. Science. Vol. 203. pp. 718723. 1979.
18
Bolin, B. The Impact of Production and Use of Energy on the Global Climate. Annual Review of Energy. Vol. 2.
pp. 197-226. 1977.
19
Vlachou, A. Vassos, S. Andrikopoulos, A. Energy and Environment: Reducing CO 2 Emissions From the Electric
Power Industry. Vol. 18. Iss. 4. pp. 343-376. Aug. 1996.
20
Carnevali, D. Suarez, C.E. Electric Power and the Environment: An Analysis of Pollutant Emissions at
Argentine State-Owned Electric Power Stations. Natural Resources Forum. Vol. 15. Iss. 3. pp. 215-219. Aug.
1991.
21
Smil, V. Energy in the Twentieth Century: Resources, Conversions, Costs, Uses, and Consequences. Annual
Review of Energy and the Environment. Vol. 25. pp. 21-51. 2000.
22
Tsoulfanidis, N. Energy Analysis of Coal, Fission, and Fusion Power Plants. Nuclear Technology/Fusion. Vol. 1.

pp. 238-254. April 1981.

12


produced more energy than they consumed. The coal and fusion plants were superior to the
fission plant. It also found that the coal cycle does not show a predominant energy consuming
sector and therefore, there is no obvious energy saving measure that can be implemented to
reduce the energy consumed. Finally, this study observed that while a fusion plant requires most
of the energy it consumes during the construction phase, the coal and fission plants need a
substantial amount of energy throughout its entire life cycle. This study illustrates the dangers of
evaluating a technology that is not yet commercial. Tsoulfanidis has to make assumptions about
what a commercial fusion technology would be. Since no commercial fusion technology is yet
even on the horizon, this is more of an exercise in imagination than science. – this technology is
still being discussed – as such, is analysis of it not still helpful? – isn’t this type of study similar
to studies (like the one that I’m working on for the Part A paper) building generation for future
demand of electricity? Based on educated predictions?
A recent paper compares the merits of renewable and non-renewable fuel sources in terms of
economic valuation for Egypt23. This study considered at least some of the externalities
associated with each fuel cycle. A life cycle cost analysis revealed that the least cost fuel system
was a 11.25 MW wind farm which was grid connected. The most expensive system considered
was a 3.3 MW photovoltaic plant. This study calculated that the capital costs of this system
would have to be reduced by approximately 60% in order to be cost competitive.
A research paper was recently written which proposes a method for conducting a life cycle
analysis of coal-based electricity generation24. This study clearly steps through disaggregating
the electricity sector in the www.eiolca.net software in order to obtain valuable information
about the coal fuel cycle. This paper should serve as the starting point for future analysis of this
fuel cycle.
Many studies focus on one particular fuel cycle and compare it to a traditional fossil fuel cycle,
however, there are several studies which consider a number of fuel cycles in one study. Both

types of studies are helpful in evaluating the best method to be applied to a future study and
therefore a range of studies will be reviewed in this section. Oak Ridge National Laboratory, as
previously stated has published studies on a number of fuel cycles, however, a few fuel cycles
are missing from the analysis and will also be discussed here.
One study employs the use of input-output analysis into a life cycle analysis method in order to
evaluate the UK economy-wide environmental implications of several fossil fuel and renewable
fuel cycles25. The types of power plants considered in this study included supercritical coal,
integrated gasifier combined cycle, combined cycle gas turbine, nuclear, tidal, wave, wind and
solar. This study divided the life cycle stages into construction, decommissioning as well as
operation of the power plant. This simplifies the life cycle considerably and potentially
influential emissions and impacts could be neglected. However, the study clearly demonstrates
23

El-Kordy, M.N. Badr, M.A. Abed, K.A. Ibrahim, S.M.A. Economical Evaluation of Electricity Generation
Considering Externalities. Renewable Energy. Vol. 25. Iss. 2. pp. 317-328. Feb. 2002.
24
Kostov, I. An Input-Output Analysis of the Environmental Implications of Coal-Based Electricity Generation. A
Course Project – 45-931. January 2002.
25
Proops, J. L, et al. The Lifetime Pollution Implications of Various Types of Electricity Generation. Energy
Policy, Vol. 24, No. 3, pp. 229-237, 1996.

13


the method involved in applying this method to the study of fuel cycles. This study considered
three air pollutants; CO2, SO2, NOx. The details of some of the systems studied are provided in
the following table:

Old coal plant baseline

CCGT
SUPC - super
critical PF
boiler with fgd
IGCC

annual output
(GWh)

electrical capacity
(MW)

efficiency
(%)

load factor
(%)

5947
2382.7

1696
340

30
53

40
80

11886
3784.3

1696
540

42
44

80
80

The results of the study are summarized in the following table. It should be noted that numerical
results reported represent changes with respect to the existing situation (relative to the “Old coal
Plant – baseline”.

Proops Results - Total effects by station
per TWh lifecycle output
CO2 (kt)
SO2 (kt)
NOx (kt)
CCGT 710.2
-13.94
-3.65
IGCC
343.2
-13.25
-3.77
SUPC
-319.4

-12.62
-2.31
SXC
-1114.6
-13.92
-4.51
Tide
-1123.7
-13.95
-4.56
Wave
-1097.7
-13.75
-4.43
Wind
-1095.6
-13.68
-4.45
Solar
-1105.4
-13.92
-4.45
Other studies, which compared several fuel cycles, did so by comparing CO2 payback times26, as
well as environmental burdens and impacts27. The first of these studies compared “alternative
energy resources” (photovoltaic cell power plant and ocean thermal energy conversion) to
“traditional sources” (coal-fired power plant, oil-fired power plant, LNG-fired power plant) as
well as hydroelectric power plants. The CO2 payback times were calculated in order to
26

Tahara, K. Kojima, T. Inaba A. Evaluation of CO2 Payback Time of Power Plants by LCA. Energy Conversion

and Management. Vol. 38. pp. S615-S620. 1997.
27
Peters, R. Methods for Assessing the Environmental Impacts of Electricity Supply Options. Performer:
Saskatchewan Energy Conservation and Development Authority. P. 46. 1994.

14


determine the CO2 reduction potential in the alternative energy resources. The two stages that
were considered in this study were construction and operation of the plant. Due to the fact that
CO2 was used as the only basis of comparison, it was not surprising that this study found that the
hydroelectric and ocean thermal plants had the shortest payback times. It was also concluded in
this paper that all of the various technologies investigated for the PV and ocean thermal plants all
had shorter payback times compared to the traditional sources.
Another study focuses on renewable electricity and stresses the need to look at the full
environmental life cycle implications of the renewable fuels such as wind, hydro, solar-thermal
and photovoltaic conversion28.
Another study discusses the use of life cycle assessment as a valuable tool even when none of the
options studied is obviously preferred over another29. It states that the information will still be
valuable by indicating which stages have the best environmental performance, where more data
is required as well as pointing out obviously unattractive options. Although this study was titled
“Life Cycle Assessment, Electricity Generation and Sustainability”, this paper was more
theoretical and only mentioned that LCA would be a good tool to evaluate the environmental
impacts of generating electricity. It didn’t actually undertake the analysis in this paper. One
other insight from this paper was the mention of a group by the name of Ecobilan from France
who have conducted several studies on the nuclear sector. These include an assessment of the
construction and management of a nuclear power plant, a comparative study of the
environmental and health impacts of nuclear and coal electricity production, LCI of spent fuel
management options, including the direct disposal cycle as well as reprocessing with uranium
recycling and plutonium use in mixed oxide fuel as well as the development of a methodology

for assessing the environmental and health impacts of nuclear energy production.
Another study describes an inventory analysis method specifically for environmental assessment
of electricity in Sweden30. This study stresses the use of exergy, a weighted grid average for
Swedish generation of electricity, and the evaluation of land areas for hydro power and quantities
of processed material for nuclear systems.
Many studies, which attempt to evaluate the effect that a fuel has on the global warming
problem, do so by determining the GWP of each fuel cycle. A recent study has attempted to
evaluate the cumulative impact a power plant has over the course of the life of that plant by
calculating the Global Warming Effect (GWE). This method of valuating the lifetime global
warming effect of each plant is helpful in comparing various fuel cycles. This study investigated
power plants fuel by hydroelectric, wind, solar, coal and natural gas. The results of this analysis
can be seen in the following table31:
28

Norton, B. Renewable Electricity – What is the True Cost? Power Engineering Journal. Vol. 13. Iss. 1. pp. 612. Feb. 1999.
29
Aumonier, S. Life Cycle Assessment, Electricity Generation and Sustainability. Nuclear Energy. Vol. 37. No. 5.
pp. 295-302. October, 1998.
30
Karlsson, R. Inventory Analysis Methodology for Electricity. Doktorsavhandlingar vid Chalmers Tekniska
Hogskola. Iss. 1409. 1998.
31
Pacca, S. Horvath, A. Greenhouse Gas Emissions from Building and Operating Electric Power Plants.
Submitted for Publication. 2002.

15


GWE from Various Power Plants (total lifetime) (MT CO2 equiv.)
Hydroelectric Photovoltaic Wind Farm Coal

Natural Gas
CO2 506,340
10,990,574 818,187
83,623,340 51,052,922
CH4 841
7,777
536
352,774
504,377
N2O 8,474
86,649
6,533
2,185,684 2,185,684
GWE 515,655
11,088,000 825,256
86,161,798 53,742,983

3. Overview of Principal Studies
Understanding the motivation driving a study is critical in assessing how well a study met its
objectives. The following is a summary of the purpose and motivation of each of the main
studies discussed in this paper. In addition, the motivation for current research in this area is
discussed.
Throughout this paper the terms “fuel cycle” and “life cycle” of different fuels are used
interchangeably. Other studies, however, have made a distinction between these two terms. For
example, the Oak Ridge study defines a fuel cycle as “the series of physical and chemical
processes and activities that are required to generate electricity from a specific fuel or resource”.
Life cycle is generally defined as “every stage of the production of electricity, from extracting
ore to final disposal of unwanted residuals”.32

Oak Ridge Laboratory

The Oak Ridge National Laboratory and Resources for the Future conducted the first study
investigated in this paper. This initiative started in February 1991 as the result of an 18 month
agreement that was made between the U.S. Department of Energy (DOE) and the Commission of
the European Communities (EC). These organizations committed to “develop a comparative
analytical method and to develop the best range of estimates of external costs from secondary
sources” for eight fuel cycles. The main objective of the study was to evaluate the environmental
impacts and other externalities for comparison by fuel cycle type. The fuel cycles considered in
this study were coal, biomass, oil, natural gas, small hydroelectric energy, uranium, photovoltaic
energy, and wind cycles. The findings of this study were published in individual reports
separated by fuel cycle from November 1992 to January 1998. These reports represent a scaled
back version of the project that was initially intended. Instead of fully examining all “secondary
source” (externalities) fuel cycle damages and benefits and private costs, the reports concentrate
mainly on the incremental or non-market damages and benefits from additions to electrical
generation capacity. The study stresses the fact that non-environmental impacts should also be
included among the “hidden benefits” and costs of energy but does not go into detail in this area.
This study employs the use of a life cycle analysis framework in order to collect, analyze and
compare the results from the different fuel cycles. In addition, the Damage Function Approach
was used to estimate damages for each impact pathway. This study also employs a marginal
investment perspective. That is, they looked forward to the consequences of future capacity
32

Society of Environmental Toxicology and Chemistry (SETAC). />
16


requirements and did not account for power plants that were already built. The benchmark for
each fuel cycle reflects 1990 investment options.
The impacts considered in this study were usually those of local, and regional consequences.
The fuel cycles that were considered in this study include; coal, biomass, hydro, oil, natural gas,
and nuclear. The original report also planned for analyzes of photovoltaic and wind fuel cycles

but they have yet to be published.
In the analysis of the coal fuel cycle, the sites that were studied were chosen based on the
availability of data and were not representative of a “typical” or “standard” power plant,
however, attempts were made to compare the same plant within each fuel cycle analysis. The
fuel cycle stages that were considered in this study included primary resource extraction and
preparation, transport and storage of resources and materials, conversion and processing as well
as disposal of plant at the end of life stage.
In general, this study focused on developing a method and framework of how to conduct a life
cycle analysis of various fuel cycles. In their application of these methods, there was a welldeveloped presentation of the externalities of these fuels cycles in terms of economic valuation.
In particular, this study was good at identifying many of the ecological impacts and estimating
their economic value. However, the technical inventory of impacts, emissions and the structure
of the plants and technologies were quite vague and not presented in a clear and detailed manner.
The data for this part of the life cycle relies, for the most part, on existing data and models and
on scientific and economic literature. In addition, the data used to analyze this part of the life
cycle is not considered the most appropriate or accurate and the selections that were made of
specific hypothetical sites which were not representative of the plants in operation today. When
the framework was implemented, many of the considerations that were presented in the method
discussion were neglected. For example, the study attempted to estimate the impact of building a
new plant. In the framework discussion, it was suggested that if additional resources would be
required to produce the new electricity (e.g. coal from a dedicated facility) then that facility
would be included in the framework. In the LCA that was conducted, it was assumed that
existing coal mines would be adequate to supply coal to the new power plant. In this particular
case, this might be a valid decision (to neglect the development and construction of a new mine).
However, extreme care should be taken in order to prevent important impacts from being
overlooked due to lack of data or for ease of calculation. Estimating these impacts is preferred to
not considering them at all.

National Renewable Energy Laboratory
The National Renewable Energy Laboratory (NREL) published a study entitled “Life Cycle
Assessment of Coal-fired Power Production” in June 1999. The main purpose of this study was

to assess the environmental impacts of current and future pulverized coal boiler systems. Three
such pulverized coal boiler systems were studied. These included a plant that represents the
average emissions and efficiency of currently operating coal-fired power plants in the U.S.
(considered status quo), a new coal-fired power plant that meets the New Source Performance

17


Standards (NSPS) and a highly advanced coal-fired power plant utilizing a low emission boiler
system (LEBS). This study is focused primarily on global warming potential and CO 2 emissions
but investigated other air, water and solid waste issues.
This study was extremely well organized and the documentation was easy to follow. However,
very little focus was given to the “impacts” section of the report. The impacts associated with
coal fired power production were discussed generally but there was no quantitative analysis in
order to understand the relative impacts of the three systems studied. The technical evaluation of
the stages of the life cycle and the options that were studied were well justified for the most part
and looking at national averages etc. provides valuable insight. However, some of the data that
these decisions relied on was dated and therefore a closer look at current technologies etc. should
be taken in order to ensure that the results of the study are not unduly influenced by older
technologies which have different environmental consequences.

Argonne National Laboratory
Argonne National Laboratories published a study in 2001 entitled “Life-Cycle Analysis of a
Shell Gasification-Based Multi-Product System with CO2 Recovery”. This study attempted to
assess and compare the “environmental footprint” of an IGCC-based multi-product system with
CO2 recovery to the footprint of a conventional IGCC-based system with only electricity
generation. The motivation for this study is the interest of the U.S. Department of Energy (DOE)
in CO2 recovery from fossil-fuel cycles as a greenhouse gas mitigation strategy.
This study is very different in nature from the other two studies considered in this paper. The
technologies investigated are more detailed than this paper delves into. However, CO 2 recovery

is a very real possibility as a method of reducing CO2 emissions in the United States and
therefore the environmental consequences of this technology should be investigated further in
future studies.

Future Research
Future study in this area is motivated by the fact that the studies conducted to date are either
incomplete, use out-of-date data or neglect to consider important factors. Since the full lifecycle
environmental impacts associated with the production of electricity are not known with certainty,
decisions will be made with incomplete, or even inaccurate, information. The costs of these
uninformed decisions are likely to be substantial. Research is required to obtain a clear, accurate
picture of these impacts.

18


Oak Ridge
Oak Ridge National Laboratory has put forth a major effort in developing a framework and
method for conducting life cycle analysis on various fuel cycles used to generate electricity. A
fundamental factor in this method is their employment of a damage function approach. This
approach follows a systematic SETAC method of determining the impacts associated with the
activities involved in generating electricity. The steps that are taken in order to create this
damage function start with the quantification of the residual emissions from the activities being
studied. Modeling is then conducted in order to determine the transport and fate of these
emissions. The physical responses (impacts) associated with the receptor areas of these
emissions are then assessed. Finally, the values of these responses are then estimated.
Willingness-to-pay estimates specific to a particular physical response in order to estimate the
damage for that response are obtained in the final step. This study also made use of an
accounting framework as well as an Impact pathway approach.
NREL
The NREL study largely based their method on that outlined by SETAC. That is, they conducted

an inventory analysis, followed by an impact analysis and finally an improvement analysis. As
previously stated, this study focused primarily on the first of these stages. This study also made
use of a database and life cycle structure provided by a private company.
Argonne
This study also follows the method of the life cycle analysis proposed by SETAC. The inventory
collection and analysis were conduced by using a computer software package and data base
developed by a private company. The software package creates an inventory for all processes
involved in construction, operation, and demolition of the plant. The inventory categories
considered in this study were resources, products, as well as airborne, liquid, and solid residues.
5. Boundaries and Details of Studies
The boundaries that are chosen for the study should be considered in terms of what it is trying to
accomplish. The boundary of the study is important when discussing the SETAC method. The
availability of data, cost and time determine how large the boundary being considered will be.
For the eiolca approach, the boundary encompasses the whole economy, excluding no sector.
The following discussion is divided into fuel cycles and the specific issues that need to be
addressed in each case specifically.
6. Coal
The fuel cycle of coal includes the types of coal considered, methods of mining and transporting
the coal, the type and size of power plant, the generation technologies used in these plants, as

19


well as the indirect effects and impacts of producing electricity at these plants. The first decision
that needs to be made is what type of plant is going to be considered. For example, the study
could consider a hypothetical plant which could be considered a “typical” plant in operation
today or that could be built to supply increased capacity requirements in the future. An existing
plant would give more accurate results, such as emissions data. If actual plants were considered
then it would have to be decided how many plants and what types of plants to consider. For
example, the age of the plant, where it is located, where the fuel source is located, where the

consumers are located etc would have to be considered. To get useful information, the study
must include several actual or fictitious plants that represent a cross section of typical plants in
operation as well as plants that could feasibly be built in the near future.
The activities within the coal fuel cycle are grouped differently in the NREL and Oak Ridge
studies. However, both studies consider many of the same process steps. A general breakdown
of stages within the fuel cycle of coal is as follows:
 Coal Mining
 Cleaning and Processing
 Transportation of Coal
 Electricity generation (including the disposal of residuals)
 Transmission
 Use
In addition to these steps, the Construction and Decommissioning stages can be important. A
simplified version of the coal fuel cycle can be seen in the diagram below. This diagram
provides example emissions and impacts that should be considered. However, this is not an
exhaustive list.
LIfe Cycle of Coal-Fired Electricity

-PM, CO and S
-Dust
-Erosion
-Waste
-Subsidence
-Land Use

Coal Mining

Construction of
Power Plant
-PM, CO and S

-waste
-water consumption

-Coal dust
-accidents
-road wear
-coal losses

Cleaning and
Benefication

Transport
of Coal

-PM, CO2, SOx, NOx
-thermal discharge
-ash sludge
-water consumption

Generation of
Electricity

Transmission and
Distribution

Use

Decommissioning
Power Plant

It should be noted that transport also usually occurs between the mining and the cleaning stages
however, the transportation of coal is considered one stage. In most studies conducted to-date,
with the exception of conservation options, the end-use stage of the energy cycles is excluded in
fuel cycle analyses. However, end-use activities of electricity vary greatly. The amount of
20


electricity consumed by each type of “use” category as well as the impacts associated with those
uses would be extremely difficult to quantify.
6.1 Power Plant Characteristics
Oak Ridge
Two hypothetical sites were studied in this analysis. These sites were chosen to illustrate the
differences in the analyses that result from different socioeconomic and environmental
conditions. Two different locations in the United States were chosen as sites for the two plants.
These sites were chosen for the coal plant study but were then held constant in the future studies
investigating other fuel cycles in order that the results could be compared. The following is a
summary of the plant characteristics of sites considered in this study:
Oak Ridge - Details of Hypothetical Plants Studied
 Benchmark plant - a conventional steam electric power
plant and is assumed to be a 500 MW facility producing
3285 GWh of electricity annually
 Represents a plant completed in 1990 and having
performance specifications such that the plant can meet the
New Source Performance Standards (NSPS)
 Particulates are controlled by an electrostatic precipitator
(ESP)
 A wet lime/limestone scrubber is used to control SOx
emissions
 Plant lifetime of 40 years
 Plant has capacity factor or 75% with an efficiency rating

of 34.5%
 The coal feed requirements for the plant at the Southeast
Reference site are 1.36 million tons of eastern bituminous
coal
 The Southwest Reference site require 1.9 million tons of
western sub-bituminous coal
 It is assumed that the existing capacities in other stages of
the fuel cycle will be sufficient to meet the needs of the
additional power plant

NREL
Three pulverized coal boiler systems were considered in this study. These include a plant that
represents the average emissions and efficiency of currently operating coal-fired power plants in
the U.S. (considered status quo), a new coal-fired power plant that meets the New Source
Performance Standards (NSPS) and a highly advanced coal-fired power plant utilizing a low
emission boiler system (LEBS). The New Source Performance Standards are summarized in the
table below:
New Source Performance Standards for Fossil-Fueled Power Plants

G/GJ heat input, HHV (lb/MMBtu)
21


NOx
SOx
Particulates

258 (0.60)
258 (0.60)
13 (0.03)

Similarly, the low emission boiler system has the following emissions standards: NOx and SOx
emissions are 1/6 of those specified by NSPS and particulate matter emissions are 1/3 of NSPS.
This study stated that depending on emissions requirements and economic considerations, a mix
of different coals are used in power plants throughout the US. However, all three plants analyzed
Illinois No. 6 coal. This was justified by the fact that it is representative of a widely available
bituminous coal, for which a considerable amount of analysis work has been performed.
A summary of the assumptions in terms of the details of the construction and decommissioning
of these power plants can be seen in the following table:
NREL - Summary of Construction and Decommissioning Assumptions
 Construction – 2 years – startup at 30% in year one – 60% other years
 Life of plant 30 years
 Construction – particulate matter high due to land prep, drilling and
blasting, ground excavation, earth moving, building of the power plant –
equipment traffic
 Asphalt paving – PVC
 Particulate and asphalt emissions, air emissions and energy required from
the processing
 Concrete, steel, iron aluminum – consumed in that order
 Construction of the barge train and truck material – all attributed to the life
cycle in question?
 Credits given for 75% of some materials being recycled (both vehicles and
building construction

Argonne
Two options were compared in this study to a study done at the International Energy Agency
(IEA). These were two integrated gasification combined-cycle (IGCC) plant designs based on
the Shell entrained-flow gasifier. The first of these was called “co-product case” which was
assumed to use high-sulfur Illinois #6 coal to produce electricity and hydrogen (H2) as energy
carriers. The second option that was considered was called the “base case”, where a

conventional IGCC power plant released CO2 by combustion of a synthesis gas in a gas turbine.
The details of the IEA study are summarized in the table titled “Comparison of Plant
Performance for Three Power Cycles”.
Power plant construction and demolition, as well as construction of hydrogen and CO2
transportation pipelines were examined in this study.

22


A summary of the details of the plants in this study are summarized in the following table:
Argonne - Summary of Assumptions for Plant Details
 Gasifier sections for these plants were identical
 Fuel use and emissions from the production of the
construction materials were estimated based on the
energy required to produce the materials
 Decommissioning involves some expenditure of
energy, depending on the future use of the site
 Assumed life of plant is 30 years for both








Construction of H2 and CO2 pipelines is included in
the scope of the analysis
Both H2 and CO2 pipelines are assumed to be 100 km
long

Assume pipelines will not be demolished
Bulk construction materials required are steel,
cement, and aggregates in the ratio of 1:1:6.
Other materials include aluminum, copper, glass, and
iron, but in insignificant amounts compared to the
first three materials.
the construction of both types of plants require equal
amounts of construction materials

Further details of the plant and the emissions for the Argonne are summarized in the table below:
Comparison of Plant Performance for Three Power Cycles
Item
Base Case
Co-Product Case
Coal Consumption
3171
3171
Gas turbine power,
272.3
62.0
MW
Steam Cycle power, 188.8
91.5
MW
Internal Power
-48.3
-77.4
Consumption, MW
Net Electricity, MW 412.8
76.1

H2 Production
423.2 – 100% effic.
(equivalent MW)
275.1 – 65% effic.
194.7 – 46% effic.
CO2 product,
0
6612

IEA Case
4823
456
354
-155
646
0
11767

23


ton/day
CO2 emissions,
ton/day
Gasification
Ash Removal
Air Separation
High-temp gas
cooling/particulate
removal

COS hydrolysis
Shift Reaction
H2S Recovery
Acid Gas Treatment
CO2 Removal
H2 purification
Combustion turbine
fuel
Steam cycle heat
source

7412

800

Shell Gasificaiton with cold gas cleanup. Raw
gas is produced at 1844 F and 352 psia.

1384
Texaco gasification with cold gas
cleanup. Raw gas is produced at
788 F

This is a slagging gasifier with slag quench.
Cryogenic air separation with partial integration (N2 used as diluent for combustion
turbine)
Used to raise highAlso used for
Used to raise high-pressure,
pressure,
combustion turbine fuel superheated steam

superheated steam
gas preheat
Single stage to form H2S and CO2
Not Applicable
Not Applicable
Two-stage shift to
Three-stage shift to convert raw
convert raw gas to high
gas to high H2 and CO2 content
H2 and CO2 content
MDEA
Glycol used for
Glycol/ether used
improved selectivity
(H2S vs. CO2)
Clasu-SCOT using
Claus-SCOT using H2
Claus plant
filtered raw gas as
Product as reagent
SCOT reagent
Not applicable
Glycol
Glycol/ether
Not applicable
Pressure Swing
Not Application
Adsorption
Synthesis gas
Residual gas rejected by Synthesis gas cleaned of sulfur

cleansed of sulfur
PSA
and particulates
and particulates
Gas turbine exhaust Gas turbine exhaust and Gas turbine exhaust and heat
heat recovery from shift recovery from shift reaction
reaction

The details of the Oak Ridge and NREL studies have been summarized in terms of plant details
in the following table:

24


Comparison of Power Plant Characteristics
Oak Ridge
NREL
Design Parameter
Southeast Southwest
Ref Site
Ref Site
Average
NSPS
Technology
PC
PC
PC
PC
360 MW (net, 425 MW (net,
Plant Capacity

500-MW (e) 500-MW (e) 100%capacity) 100%capacity)
Operating Capacity
Factor
75%
75%
60%
60%
Power Plant Efficiency 35%
35%
32%
35%
Modified Avg
Type of Plant
Specific SiteSpecific SiteAvg Nat’l Data Nat’l Data

LEBS
PC
404 MW (net,
100%capacity)
60%
42%
Modified Avg
Nat’l Data

In summary, picking one or two, real or hypothetical sites, is not representative of all the
combinations of the available choices and options (with differing environmental impacts) that are
present for the production of electricity from coal.

6.2 Mining
There are various methods of removing coal from the ground. The choice of method used

depends on the depth, thickness and configuration of the coal seams.33 In 2001 62.5% of coal
mined in the US was obtained through surface mining techniques; the rest was obtained through
underground mining activities34. Even within these two categories, there is a wide range of
techniques, methods and equipment used. Surface mining can be performed on flat, shallow
deposits. This method is generally less costly per ton mined than underground mining however,
the cost varies depending on the conditions of the mining site. Strip mining is the type of surface
mining that is the most economical. It consists of removing the coal and the overburden in
parallel where the overburden is filled back into the space where the coal was previously. Open
pit mining is another form of surface mining and this is where thick seams of coal are removed
by traditional quarry methods35.
There is a specific mining technique that also falls into the surface mining category which is the
topic of much discussion recently. This type of mining is called mountain top mining and it
consists of removing the top portion of a mountain in order to expose coal deposits below. The
coal is removed using various surface mining techniques and the overburden is usually moved to
adjacent valleys for disposal. This mining technique is gaining popularity in states like West
Virginia where 99% of their electricity is from coal and they have a large number of mountains
containing relatively low sulfur coal36. The result of this kind of mining has numerous
33

World Bank Group. Pollution Prevention and Abatement Handbook. Coal Mining and Production. July 1998.
Office of Surface Mining. Bureau of U.S. Department of the Interior. Tonnage Reported for Fiscal Year 2001.
/>35
World Bank Group. Pollution Prevention and Abatement Handbook. Coal Mining and Production. July 1998.
36
Coal Age. Coal Industry Hails Supreme Court Ruling. March 2002. p6.
34

25