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From a hard place to a rock: Questioning the energy security of a coal-based economy
Energy Policy 39 (2011) 4664–4670
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From a hard place to a rock: Questioning the energy security of a coal-based economy Benjamin K. Sovacool a,*, Christopher Cooper b, Patrick Parenteau c a Centre on Asia and Globalisation, Lee Kuan Yew School of Public Policy, National University of Singapore, Oei Tiong Ham Building, 469C Bukit Timah Road, Singapore 259772, Singapore b Institute for Energy and Environment, Vermont Law School, Royalton, VT, USA c Environmental and Natural Resources Law Clinic, Vermont Law School, Royalton, VT, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 10 April 2011 Accepted 27 April 2011 Available online 11 May 2011
We thank Brathwaite et al. for starting a very useful debate about what role, if any, coal should play in future energy transitions. Expanding upon their piece, we question that a coal-based economy, in which energy production for both electricity and transport comes from coal, can meet the energy security needs of the United States and other countries. & 2011 Elsevier Ltd. All rights reserved.
Keywords: Clean coal Carbon capture and sequestration Coal-to-liquids
1. Introduction ‘‘Frosty the Coalman, he’s getting cleaner every day. He’s affordable and adorable and the workers keep their pay. He’s abundant here in America, And he helps our economy rolly’’ The Clean Coal Carolers
Concerned about coal’s negative image during the Holiday Season, in 2008, the American Coalition for Clean Coal Electricity sponsored a multi-million dollar advertising campaign designed to coopt Christmas in the name of commerce. The campaign featured singing lumps of coal called ‘‘The Clean Coal Carolers’’ merrily crooning the benefits of ‘‘clean’’ coal (Radmacher, 2008). While not quite as entertaining as operatic anthracite, we still enjoyed reading Brathwaite et al.’s (2010) article on the transition to a coal-based economy. It contends, among other arguments, that moving away from an energy economy based on oil to one based primarily on coal could bring the United States many benefits. Brathwaite et al. tell us that coal is abundant, stable in price, and capable of reducing U.S. dependence on imported oil. As the authors remark (pp. 6086–6085), ‘‘coal-to-liquid fuels are attractive due to the vast reserves (over 200 billion short tons of the demonstrated reserve coal base) available for mining;’’ ‘‘due
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DOI of original article: 10.1016/j.enpol.2011.04.069 Corresponding author. Tel.: þ65 6516 7501; fax: þ 65 6468 4186. E-mail address: [email protected] (B.K. Sovacool).
0301-4215/$ - see front matter & 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.enpol.2011.04.065
to the nature of coal mining and the political stability of major coal mining nations, the prices for coal are more stable than the prices for natural gas or oil;’’ and ‘‘a transition to a coal economy is desirable to reduce the dependence on foreign oil supplies.’’ The article also points out some of the constraints to a coal-to-liquids strategy, namely the fact that refining coal into gasoline is much less efficient than the conversion process for petroleum and that both coal and oil take millions of years to replenish. We appreciate, as well, that the authors engage some of our own recent work on energy security (Sovacool and Brown, 2009, later published in Sovacool and Brown, 2010). However, Braithwaite and her colleague’s assessment of the benefits and barriers to a coal economy is incomplete; it focuses primarily on coal use in the transport sector, and also only in a limited way addresses coal’s impact on energy security, affordability, availability, efficiency, and stewardship. Expanding upon their piece, we question that a coal-based economy, one in which energy production for both electricity and transport comes primarily from coal, can meet the comprehensive energy security needs of the United States and other countries. To clarify, we understand ‘‘clean coal’’ to refer to a collection of four technologies and processes: (a) supercritical pulverized coal plants that boost thermal efficiency by operating at higher temperatures, (b) integrated gasification combined cycle (IGCC) plants that use chemical processes to gasify coal and remove sulfur and mercury, (c) pressurized fluid bed combustion plants that use elevated pressure to capture sulfur dioxide and nitrogen oxides, and (d) carbon capture and storage (CCS) techniques such as deep underground geologic formations that are engineered to
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Table 1 Four criteria of energy security. Criteria
Underlying values
Explanation
Availability
Independence and diversification
Diversifying the fuels used to provide energy services as well as the location of facilities using those fuels, promoting energy systems that can recover quickly from attack or disruption, operating a reliable system, and minimizing dependence on foreign suppliers Providing energy services that are affordable for consumers and minimizing price volatility Improving the performance of energy equipment and altering consumer behavior Protecting the natural environment, communities and future generations
Affordability Equity
Efficiency
Innovation and consumer education
Stewardship Social and environmental sustainability
capture and store excess CO2 (Logan et al., 2007).1 By coal-toliquids (CTL), we mean fuels produced by the Fischer–Tropsch process, a gas-to-liquid conversion technique that uses a catalyzed chemical reaction to heat coal and transform the resulting carbon monoxide and hydrogen into a colorless, odorless fuel that can supply any engine that can operate on diesel fuel. We conceptualize a ‘‘coal-based economy’’ as relying almost exclusively on coal with CCS for electricity generation, and transportation fueled by CTL. Drawing from Sovacool and Brown (2010), we concur that energy security consists of the four criteria listed in Table 1. We begin by discussing the efficiency implications of a coal-based economy before assessing affordability, availability, dependence, and sustainability.
2. Efficiency implications Perhaps the most significant way in which a coal-based economy would be energy inefficient involves conversion inefficiencies for both CCS and CTL. CCS and CTL are approaches which ignore consumer efficiency and demand side management, and both accrue significant energy penalties. The International Energy Agency (2009) has noted that, for instance, CCS requires a substantial amount of heat and complex processes such as amine solvent regeneration and flue gas pre-treatments, which when combined with the need for auxiliary power, blowers, pumps, and compressors, reduces the operating efficiency of a coal power plant by 8% to 10%. According to the IPCC (2005), widespread adoption of CCS could erase the energy efficiency gains made in the last fifty years and increase coal consumption by one-third. Even then, actual capture rates are not perfect, with 15% of carbon 1 Almost all clean coal technologies rely on a four-step process of capturing, storing, transporting, and sequestering CO2. The ‘‘capture’’ stage requires separating CO2 from emissions and exhaust into pure waste streams, then pressurizing it for transport. While effective at preventing carbon from escaping directly into the atmosphere, capturing creates serious tradeoffs in operating efficiency. The easiest way to capture CO2 is to ‘‘scrub’’ it from the flue or exhaust gas using a chemicallike amine to extract the greenhouse gas. But this process entails a significant energy penalty. Carbon capture and storage involves capturing CO2 from coal-fired power plants and other fossil-fuel sources, condensing it, transporting it, and injecting it deep (4800 m) underground into secure geologic formations, and closely monitoring it to make sure it stays put for centuries. Though CCS technology has been used in many small scale projects around the world, mainly for secondary recovery in natural gas and oil fields, it has not been demonstrated at anywhere near the scale that would be required to permanently store all the CO2 from the burning of coal and other fossil fuels at projected rates of energy consumption.
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dioxide escaping into the environment (International Energy Agency, 2009: p. 13). Moreover, Page et al. (2009) found a disturbing discrepancy between simulated energy efficiency penalties for CCS plants reported by vendors and the plants’ actual operating performance. The reported efficiencies were 8–15.4%, but resulted mostly from process simulations. A vast majority of these simulations were not published in reputable journals but in ‘‘gray’’ literature, publications from governments and industry that have no independent peer review or check on quality assurance. The researchers also found considerable cross referencing of conference papers as primary sources, and reliance on data from only the three sites at Sleipner, Salah, and Weburn (which the authors even cautioned as inadequate). Such sites are very small, storing only 3–4 million tons of CO2 per year, compared with 8 billion tons emitted annually from coal and the 50 billion tons from all sources of greenhouse gas emissions per year. Because much of the CO2 stored at these sites did not come from power plants themselves but were derived from natural gas processing, performance calculations did not include power losses that would occur related to steam diversion in the separation process at actual CCS facilities. Page et al. warned that such information contrasts sharply with data from a ‘‘real world scenario’’ where considerable energy losses would be required to capture, compress, transport, and store CO2. Their calculations suggest energy penalties between 43.5% and 48.6% (depending on whether CO2 was liquefied or compressed), which are almost twice as large as projections from the industry. As the authors concluded, ‘‘CCS is not presently a near-term measure for mitigating greenhouse gas emissions y In light of the tension between the current status of CCS and the need for rapid and deep emissions contractions y the value of further investment in CCS must be seriously questioned’’ (Page et al., 2009: p. 9). Many of the efficiency challenges to CCS identified by Page et al. have been confirmed by attempts to build such plants in practice. While defending TXU Energy’s plan to build 11 new coalfired units in Texas, instead of newer CCS systems, one TXU vice president noted: IGCC is a promising technology, but is not yet viable on a largescale commercial basis for the types of coal available in Texas. There are only two IGCC units in operation today in the U.S.—both are small, were heavily subsidized, and actually have dirtier emission profiles than the supercritical plants we have proposed. Further, both these plants continue to operate at low reliability levels more than five years after coming on line (Tulloh, 2007). One assessment of the 15 integrated gasification combined cycle (IGCC) power plants operating around the world since 1984 (without carbon sequestration) in Germany, Italy, Japan, Netherlands, Singapore, Spain, and the United States found that all were prone to a host of reliability issues including difficulties with maintenance, high sensitivity to the types of coal used, and frequent malfunctions with auxiliary systems. Given these problems, facilities in aggregate operated only 28.5% of the time, or operated for 35,000 h out of a potential 122,640 h (Franco and Diaz, 2009). To make matters worse, in many cases plants must capture, compress, transport, and store two to three tons of CO2 to offset every ton emitted. Sigmon (2008), a senior vice president at American Electric Power, estimated that, given the energy-intensive nature of carbon capture, his company would have to sequester two tons of carbon for every one ton emitted, at a cost of $40–$45 for every ton of carbon displaced.
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The technological and economic inefficiencies associated with coal-to-liquids conversion are even starker. In 2007, the National Petroleum Council (NPC) issued preliminary studies used to compile its report Facing the Hard Truths about Energy. In a study from NPC’s coal-to-liquids and gas subgroup, industry experts estimated the thermal efficiency of direct liquefaction of coal to be between 50% and 54% (Bellman et. al., 2007). This estimation, however, may be misleading. It appears the industry calculates thermal efficiency by comparing the heating value of the resulting liquid fuel to that of the energy value of the inputs. But direct liquefaction is a two-stage process, requiring hydrogen inputs during the first process and oxidizing inputs during the second. How the industry derives and accounts for all of the inputs involved in this calculation reveals it to be based on a domino-effect of various processes reminiscent of a Rube Goldberg contraption (which were not known for their efficiencies). The first stage in direct coal liquefaction is a thermal process that breaks down the structure of the coal. To prevent the coal from re-polymerizing, however, the process requires the injection of hydrogen at high pressures. According to the NPC report, plants can supply this hydrogen feedstock (though not the pressure) as a by-product of coal gasification (presumably occurring at the same facility). In coal gasification, high-purity oxidants are used to partially oxidize the carbon in the coal feedstock. These oxidants, however, are derived from cryogenic air separation, a process of splitting air into its constituent parts by distilling it at sub-freezing temperatures. Cryogenic air separation itself requires huge amounts of energy. Atmospheric air must be filtered to remove dust and then compressed, and it has to pass through plane fin heat exchangers before being injected (again under pressure) into a refrigerated cryogenic distillation column. The process of ‘‘directly’’ liquefying coal, then, requires a feedstock from an entirely different gasification procedure that itself depends on the by-product of a wholly separate cryogenic distillation process. Each step in this Goldbergian system consumes enormous amounts of direct and indirect energy, almost none of which appear to be accounted for in the input calculation of CTL thermal efficiencies. The calculation of CTL thermal efficiency also appears to assume an entire production system (air distillation, gasification, and liquefaction) built at each facility. In tacit acknowledgment of these assumptions, the NPC report admitted that CTL could amount to only 20% of the U.S. petroleum market under the most optimistic scenario. Under more realistic conditions, however, CTL’s market share falls to somewhere between 0% and 6% (Bellman et al., 2007).
3. Affordability and price implications A coal-based economy not only would be inefficient, it would be prohibitively expensive. The International Energy Agency (2009) calculates that capturing carbon dioxide from flue gas streams at coal- and gas-fired power plants would cost more than $50 million to capture less than 5 million cubic meters. Because of the energy penalties involved, a 2007 interdisciplinary study from the Massachusetts Institute of Technology (MIT) concluded that carbon capture and storage technologies would cost about $25 per ton of CO2 to capture and pressurize and another $5 per ton to transport and store (Katzer et al., 2007). If implemented widely, the MIT team calculated the carbon capture and storage technologies would almost double the cost of coal-fired power. More recently, Charles (2009) estimated that a carbon price of $60 per ton would be required to make CCS competitive.
A modern subcritical pulverized coal plant produced power at about 4.84 b/kW h in 2006. But the cost of generation jumps 70% (to 8.16 b/kW h) when accounting for carbon capture and sequestration. The MIT study also found that if all of the CO2 emitted from power plants in 2006 were transported for sequestration, the quantity would be three times the weight and one-third the volume of natural gas transported by the entire U.S. natural gas pipeline system annually. If just 60% of the CO2 emissions were to be captured and compressed in liquid form for geologic sequestration, the volume of liquid carbon per day would be equivalent to all of the oil currently consumed in the United States (equal to about 20 million barrels of oil per day). The researchers argued that no CO2 storage project is currently attuned to overcoming these problems, since every large-scale clean coal system would have unique, complex characteristics that make them ill suited for mass production. Nordhaus and Pitlick (2009) similarly calculated that at a large-scale CCS would require a pipeline network comparable in size to the entire existing natural gas infrastructure. Assuming natural gas pipelines cost $420,000 per mile and the country currently requires 1.4 million miles of them, constructing a new CCS pipeline network on this order could cost as much as $58 trillion! This estimate may even be conservative considering that CCS would need to be deployed at biomass and natural gas power plants, in the fuel transformation and gas processing sectors, and in emissions-intensive sectors such as cement, iron, steel, chemicals, and pulp and paper manufacturing (International Energy Agency, 2010a). Clean coal and CCS facilities are also prone to cost overruns and significant delays. The U.S. Department of Energy’s (DOE) FutureGen program is a case in point. Industry estimated that the program would have a net cost of $1.5 billion ($1.1 billion from the taxpayers); design would take 5 years, and initial operation would take another 5 years. The DOE withdrew funding in 2008 after the industry had spent twice as much as first estimated. Even then, the FutureGen plant was to incorporate IGCC with pre-combustion capture, unlike the vast majority of coal-fired power stations that require post-combustion capture. The newly restructured FutureGen, launched in 2009, has its first demonstration project targeted for 2015, allowing plenty of time for additional cost overruns and technical hurdles to arise (Page et al., 2009). Davison and Thambimuthu (2009) surveyed all of the other state-of-the-art carbon capture and storage facilities in 2009 and noted that, based on current technology, advanced clean coal plants required 15–45% more fuel compared to ordinary plants. These energy penalties result in an increased gross cost of electricity generation of 30–80%. A separate nonpartisan study commissioned by the DOE admitted that IGCC and CCS systems, due to their higher capital costs compared to conventional plants, would result in incremental increases in electricity generation costs of 36–81% (Committee on Climate Change Science and Technology Integration, 2009). Similarly, an interdisciplinary European research team looking at the performance of new CCS plants in Australia, China, France, Germany, India, Japan, Korea, United States, United Kingdom, and the Nordic countries estimated extra costs of US$20 to 95 per ton of carbon dioxide captured and sequestered, and cautioned that the average conversion efficiency of coal-fired power plants would continue to be low. Using the best state-of-the art technology, the researchers estimated that the best efficiencies these plants could achieve would be no better than 29–41% (InterAcademy Council, 2007: pp. 62–73). A separate European Commission study confirmed that European CCS facilities would likely see increases in the cost of power generation of 40–80% compared with conventional plants, with an energy penalty of 11–40% (European Renewable
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Energy Council, 2007). Moreover, the nonpartisan U.S. Congressional Budget Office (2007) surveyed the potential for CCS in the United States and found that CCS ‘‘had not yet been demonstrated’’ on the scale necessary to seriously mitigate emissions. They estimated that the price of a single ton of CO2 would have to be $15–90 before CCS power plants would become cost competitive with other energy generation. Even more disturbing, the report found that even if all known oil fields, geologic sites, aquifers, and depleted reservoirs were converted for CCS, it would be insufficient to meet U.S. carbon storage needs (though some other reports have shown differently). Incredibly, these problems are likely to get worse, not better, over time. Hansson and Bryngelsson (2009) looked at future projections of CCS costs, and found common assumptions that expenses would decrease over time due to learning and experience were wrong. Instead, after surveying a large number of experts in the field, they found that costs likely would go up due to ‘‘negative learning’’ and the risk of leakage. By their calculations, even an annual global leakage rate of 0.5%, excellent in terms of operational efficiency, would be completely unacceptable for climate change mitigation. To successfully address climate change, systems would need to achieve perfection, which even American football coach Vince Lombardi admitted was unattainable. Other studies have spotlighted the need for further research to improve carbon transport and storage phases, system integration, and the retrofitting of old plants before CCS is ready for any type of commercialization. Significant research entails significant added cost (Markusson and Haszeldine, 2008). The International Energy Agency (2010b) reports that a minimum of $36.1 billion in research funds will need to be spent on demonstration projects before engineers can determine whether such plants can even function in the real world. Perhaps this explains why an assessment in Nature also concluded that ‘‘the probability of carbon capture and storage being widespread in 10 or even 20 years is very low’’ (Schiermeier et al., 2008: 822).
4. Availability and dependence implications Brathwaite et al. (2010) note that the abundance of coal in the United States makes it likely that reserves will not be depleted until ‘‘well beyond’’ 2100, and that coal-fired electricity is a ‘‘mature industry’’ with more than a century of experience generating electricity. However, though coal is abundant in the United States, it is scarce globally. Indeed, 80% of the world’s coal can be found in just 8 countries. In Germany, Schreiber et al. (2010) note that because CCS and clean coal technologies are less efficient (and would require greater amounts of coal imports), their use can significantly increase the country’s dependence on coal imports. They projected that Germany would require 50 million tons of additional lignite if the country embarks upon a CCS path compared to relying on coal without CCS. So for countries beyond the United States, CCS could only increase import dependence and costs. Moreover, even if the fuel for coal were widely available, CCS technology is not. Florini and Sovacool (2011) have documented how the United States and other European countries have refused to distribute clean coal technology to countries such as China or India out of intellectual property concerns. The United States Agency for International Development (2007) surveyed prospects for clean coal development in China, India, Indonesia, Philippines, Thailand, and Vietnam, and found little incentive for these countries to rehabilitate, retrofit, upgrade, or improve coal-fired power stations. This was partly due to the difficulty of acquiring CCS technology, and partly due to the perception that such technologies were costly, unproven, and risky.
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5. Stewardship and sustainability Brathwaite et al. (2010) do acknowledge that coal has numerous social and environmental externalities, but dedicate only a few sentences to this claim. The Department of Trade and Industry in the United Kingdom (2010) recently noted that power plants with CCS will ‘‘increase [GHG] emissions and air pollutants per unit of net delivered power and will increase all ecological, land-use, air-pollution, and water-pollution impacts from coal mining, transport, and processing, because the CCS system requires 25% more energy, thus 25% more coal combustion, than does a system without CCS.’’ Indeed, even with capture and storage coal is likely the dirtiest of all energy systems. Thomas Sundqvist and Patrik Soderholm analyzed as many externality estimates they could find (132 in all) to determine the extent that fossil fuels, nuclear power, and renewable energy systems imposed unpriced damages on society (Sundqvist and Soherholm, 2002; Sundqvist, 2004). They found that net costs (negative externalities outweighed positive ones) ranged from a low of 0 b/kW h to a high of almost 73 b/kW h for various technologies, with a mean of 15 b/kW h for coal, making it the largest (e.g, the most damaging) of all sources depicted in Fig. 1. When updated to $2007, coal generation created $228 billion in additional costs and damages in the United States alone for that year (Sovacool, 2008). Harvard Medical School (2011) researchers recently determined that the lifecycle impacts of coal and its waste stream cost the U.S. public as much as $500 billion annually. These figures cannot capture many of the deleterious impacts from coal that defy easy measurement. For example, greater reliance on CCS and CTL would mean that mining accidents and black lung disease would kill more coal miners every year. Mountaintop removal mining would devastate Appalachian watersheds. Acid rain would destroy alpine lakes and boreal forests. Mercury would contaminate an increasing number of aquatic ecosystems and fisheries. More national parks would be shrouded in haze. More toxic chemicals would leach from combustion waste facilities and pollute groundwater and drinking water supplies. Fine particulates and other contaminants in soot and smog would increase rates of human mortality and morbidity. In short, coal would sustain its place as arguably the dirtiest, most dangerous, and most ecologically destructive source of energy on the planet. No matter what happens upstream at the coal plant or CCS facility, coal extraction and processing will still greatly affect the quality of water and land resources, and coal will still need to be
20 18 16 14 12 10 8 6 4 2 0
Fig. 1. Environmental externalities associated with electricity generation technologies (2007 U.S. Cents/kW h). Source: Sovacool (2008).
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transported. Because CCS systems exact an energy penalty, they will require more coal to produce each unit of electricity, exacerbating all of these downstream impacts (Boute, 2008). Failing coal slurry impoundments, saline pollution from coal-bed methane recovery, and occupational safety and health hazards (including mine-related deaths) are also among the other impacts of continued reliance on coal-fired electricity production (Sobin, 2007). The most visible environmental impact is coal mining. Of more than one billion tons of coal mined in the United States annually, roughly 70% comes from surface mines. Mountaintop removal (a newer technique for mining coal that uses heavy explosives to blast away the tops of mountains) has destroyed streams, blighted landscapes, and diminished the water quality of rural communities. Palmer et al. (2010) have argued that the impacts of mountaintop removal ‘‘are pervasive and long lasting and there is no evidence that any mitigation practices successfully reverse the damage it causes.’’ One estimate calculated that mountaintop removal has destroyed 1.5 million acres of hardwood deciduous forests and 500 mountains in the Eastern part of the United States alone (Biggers, 2009). Underground coal mining, responsible for the remaining 30% of mining in the U.S. and most mining worldwide, remains a highly dangerous industry. Underground coal miners must confront highly explosive methane gas, geological conditions that make mine roofs notoriously unstable, the ever present dangers posed by fire, and flooding from nearby abandoned mines. Twelve miners lost their lives in 2006 at the Sago mine in West Virginia after an explosion forced them to barricade themselves in the mine to await a two day rescue. The episode was a stark reminder that miners do not escape these risks even in the highly regulated U.S. coal mining sector. The U.S. Government Accountability Office (2008) has warned that, despite new legislation, many mines still operate in violation of safety standards. In some districts in West Virginia and Kentucky, two-thirds of mines have been issued citations for not complying with federal standards. Globally, coal mining activities have taken their toll on local environments and communities. Exploration activities involve drilling and vegetation clearing, trench blasting, and geophysical surveying that can result in habitat loss, sedimentation, and deforestation due to road development. Site preparation has been shown to fragment ecosystems, increase demand for water resources, change predation rates, and accelerate the chemical contamination of land. Mining operations require supporting infrastructure, such as roads, electricity, processing facilities, and ports. Once closed, abandoned mines pose dangers such as physical injury, persistent contaminants in surface and groundwater, and acid drainage affecting hundreds of thousands of streams (Miranda, 2004). Mining’s social impacts can be just as grave. One assessment of the global mining industry identified many coal mines located in communities plagued by corruption, civil unrest, and lack of participation in civil society. The study warned that nearly onequarter of active mines and exploration sites are located in countries exhibiting the weakest governance structures (Miranda, 2004). These regimes also have the least stringent environmental controls. They rarely regulate or prohibit dumping and disposing of mine wastes. More than one-quarter of the world’s active mines overlap with or are within a 10 km radius of strictly protected areas or intact ecosystems of high conservation value; about one-third of all active mines are located in stressed watersheds; and one-fifth of active mines and exploration sites are in areas of high or very high seismic hazard. Coal mining also supports unstable and uneven development, with boom-and-bust cycles affecting mining towns and wide fluctuations in economic activity over a short timeframe (Miller, 1979).
Examples from China are most prominent. The Chinese coal sector employs 7.8 million people and produces about 40% of the world’s coal. Yet it accounts for 80% of the total deaths in coal mine accidents worldwide. In 2005 alone, according to official figures, Chinese mines recorded 3306 accidents and 4746 mining deaths in 2006 (WWF, 2007). Coal miners that survive the workplace face the risk of black lung disease (pneumoconiosis). China is already home to more than 600,000 black lung patients, with 1167 new cases and 163 deaths per year from the state-owned coal sector. Accounting for the depletion of arable soil, diminishing water supplies, severe air pollution leading to grave respiratory illness, displaced and disenfranchised communities, and coal mining accidents and deaths, the true cost of Chinese coal is estimated to be at least 56% higher than its market price (WWF, 2007). The safety and reliability of CCS sites is another serious concern. Storage of CO2 must be safe, cost-effective, and permanent if it is to become a viable climate mitigation strategy, yet sites would be subject to seismic dangers. Given the enormous amount of CO2 that must be stored, even a tiny amount of leakage could prove disastrous for the climate. To be a successful burial site, a geologic formation must be more than 1 km underground. That depth provides enough pressure to turn CO2 from a gas into a supercritical fluid, a form in which the CO2 is more likely to stay put. Ironically, however, the formation also has to be porous enough, with cracks and cavities to hold massive volumes of CO2. Lastly, it needs to be covered with a layer of non-porous rock to provide a leak-proof cap. Identifying sites that have the needed permanence, cost, and safety requirements is an enormously complicated issue, and considerable underground testing must occur before injection begins. The environmental and liability issues associated with merely finding and testing sequestration sites are challenging and unresolved (Kerr, 2008). Escaping CO2 can also kill people. One large bubble of CO2 released from a volcanic lake in Cameroon suffocated more than 1700 people in 1986. Blackford et al. (2009) have argued that even slow and chronic rather than abrupt and sudden leaks can poison marine environments, acidify seawater, and harm mussels, starfish, and urchins with ‘‘potentially severe’’ ecological impacts. Groundwater contamination can occur if stored CO2 leaks or unexpectedly migrates. CO2 injection can result in pressure buildup and increase seismic activity. Operational leakage to the surface can create a public health risk since high concentrations of CO2 can induce fatal asphyxia. Slow, sudden, or chronic releases of CO2 can to the surface can accelerate climate change. Environmental degradation can occur as sequestered CO2 leaks to the surface and impacts vegetation, trees, and soil composition (de Figueiredo, 2007). A final environmental concern is water. Court et al. (in press) have shown that a coal-fired power plant retrofitted for CCS requires twice as much cooling water as one without CCS. CTL fares even worse. While the total amount of water required for liquefaction depends on factors like plant design, coal properties, location, and humidity, on average liquefaction using advanced Fischer–Tropsch Technology requires approximately 5.0–7.3 gallons of water for every gallon of liquid fuel produced (Elcock, 2008). The water-intensity of a coal-based economy does not bode well for coal’s ability to address climate change concerns, especially when population growth, electricity demand, and summer heat seem likely to increase simultaneously throughout the United States. Some of our own published studies have noted that 22 counties and 20 large metropolitan areas in the U.S. could experience severe water shortages by 2025 (Sovacool, 2009; Sovacool and Sovacool, 2009a, b). Greater reliance on coal and other thermoelectric power plants could therefore deplete the water available from Lake Lanier in Georgia and exacerbate interstate litigation between Tennessee, Alabama, and Florida.
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Biodiversity could perish along the Catawba-Wateree River Basin in North Carolina. Chicago could find itself embroiled in domestic and international legal disputes over the consumption and withdrawal of water from Lake Michigan. Households and businesses could run out of water from the South Platte River in Colorado. Rivers could stop recharging the groundwater needed for drinking and irrigation in Texas. Lake Mead and the Colorado River could continue to suffer drought, drastically affecting the state of Nevada, inducing an agricultural crisis in California and Mexico. Fisheries along the Hudson River in New York could collapse. The Delta Smelt could become extinct in the San Joaquin River Basin in California. These impending but avertable risks serve an important reminder that climate change is not the only serious environmental issue affected by a coal-based energy economy.
6. Conclusion We thank Brathwaite et al. for bringing into focus some of the energy security concerns associated with a transition to CTL in the United States. Building from their work, our own assessment questions whether CCS and CTL can ever contribute positively to energy security within the United States and beyond. Because the myriad processes required to render coal safer and cleaner exact large energy conversion penalties, a transition to a coal-based economy would require vastly more coal to generate the same amount of energy. That means, even on a per unit basis, a coal-based economy will exacerbate the risks inherent in coal mining, processing, combustion, and clean-up. But transitioning to a coal-based economy will also require more actual units of energy to replace units currently supplied by oil, natural gas, and a plethora of other fuels. Thus, the coal’s economic, social, and environmental risks expand exponentially as it begins to replace other fuels. Then there is the matter of opportunity cost. In a world of scarce resources and only a few decades within which humanity has to address climate change, scaling up coal systems seems a dangerous waste of resources. We cannot afford to build out two huge energy infrastructures at the same time, nor can we achieve efficiency goals while building plants that must operate for 50 year to recoup investments. Coal pathways themselves raise energy security risks. For all industrial purposes, CCS remains largely unproven. When it does prove viable, it will require massive new capital costs and entail enormous long-term liabilities. Spreng et al. (2007) have noted that clean coal is similar to nuclear power in this respect. Like high level nuclear waste, CCS systems would need to carefully manage carbon dioxide for incredibly long periods of time. They would have to operate perfectly to achieve climate change goals and protect human health and the environment. Imagine the difficulty the International Atomic Energy Agency and Nuclear Regulatory Commission have in managing relatively small volumes of nuclear waste, and consider that the volume of carbon dioxide emitted into the atmosphere each year is in the billions of tons. Every aspect of a coal-based economy exacts greater external costs from the increased mining, transportation, processing and combusting of coal. Some of these costs will be reflected in higher energy costs, squeezing a burdened underclass and crippling an economy in tentative recovery. But many costs will not be reflected in energy prices. These include the increased deaths from coal mining, the increased morbidity and mortality associated with inhalation of particulates, the devastation of the sight and soul of rural mining communities, and the heightened competition over dwindling sources of potable water. In theory we may achieve the technological capability to transition from oil
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dependency to an independent coal-based economy. But, pursuing more CCS and CTL research and development risks delaying more durable measures and diverts resources from more effective alternatives like energy efficiency and renewable resources. In the end, the social, economic, and environmental costs of transitioning to a coal-based economy would continue to keep us somewhere between a rock and a hard place.
References Bellman, D., et. al., 2007. Coal to Liquids. Working Document #18 of the NPC Global Oil and Gas Study. July 18. Biggers, Jeff, 2009. Reckoning at Coal River. Huffington Post. Blackford, J., Jones, N., Proctor, R., Holt, J., Widdicombe, S., Lowe, D., Rees, A., 2009. An initial assessment of the potential environmental impact of CO2 escape from marine carbon capture and storage systems. Proceedings of the Institute of Mechanical Engineers 223, 269–280. Boute, Anatole, 2008. Carbon capture and storage under the clean development mechanism—an overview of regulatory challenges. Carbon and Climate Law Review 2 (4), 339–352. Brathwaite, J., Horst, S., Iacobucci, J., 2010. Maximizing efficiency in the transition to a coal-based economy. Energy Policy 38, 6084–6091. Charles, D., 2009. Stimulus gives DOE billions for carbon-capture project. Science 323, 1158. Committee on Climate Change Science and Technology Integration, 2009. Strategies for the Commercialization and Deployment of Greenhouse Gas IntensityReducing Technologies and Practices. U.S. Department of Energy, Washington, DC January, 2009, DOE/PI-0007. Congressional Budget Office, 2007. The Potential for Carbon Sequestration in the United States. CBO, Washington, DC. Court, Benjamin, Celia, Michael A., Nordbotten, Jan M., Elliot, Thomas R., Active and integrated management of water resources throughout CO2 capture and sequestration operations. Energy Procedia, in press. Davison, J., Thambimuthu, K., 2009. An overview of technologies and costs of carbon dioxide capture in power generation. Proceedings of the Institute of Mechanical Engineers 223, 201–212. de Figueiredo, Mark, 2007. The Liability of Carbon Dioxide Storage. Ph.D. Thesis. MIT University. February 2007. Department of Trade and Industry in the United Kingdom, 2010. The Energy Challenge. Available at /http://webarchive.nationalarchives.gov.uk/ 20101209210643/webarchive.nationalarchives.gov.uk/ þ/http://www.berr. gov.uk/files/file32014.pdfS. Elcock, D., 2008. Baseline Projected Water Demand Data for Energy and Competing Water Use Sectors. Report #ANL/EVS/TM/08-8. NovemberNational Energy Technology Laboratory. European Renewable Energy Council, 2007. Future Investment: A Sustainable Investment Plan for the Power Sector to Save the Climate. European Renewable Energy Council, Brussels. Florini, A.E., Sovacool, B.K., 2011. Bridging the gaps in global energy governance. Global Governance 17 (1), 57–74. Franco, Alessandro, Diaz, Ana R., 2009. The future challenges for clean coal technologies: joining efficiency increase and pollutant emission control. Energy 34, 348–354. Hansson, Anders, Bryngelsson, Marten, 2009. Expert opinions on carbon dioxide capture and storage—a framing of uncertainties and possibilities. Energy Policy 37, 2273–2282. Harvard Medical School, 2011. Mining Coal, Mounting Costs: The Lifecycle Costs of Coal. Center for Health and the Global Environment, Boston. InterAcademy Council, 2007. Lighting the Way: Toward a Sustainable Energy Future. IAC Secretariat, Amsterdam, pp. 62–73. International Energy Agency, 2009. Global Gaps in Clean Energy Research, Development, and Demonstration. OECD, Paris. International Energy Agency, 2010a. Technology Roadmap: Carbon Capture and Storage. OECD, Paris. International Energy Agency, 2010b. Carbon Capture and Storage: Progress and Next Steps. OECD, Paris. Intergovernmental Panel on Climate Change[IPCC], 2005. Carbon Dioxide Capture and Storage. IPCC, Geneva. Katzer, James, et al., 2007. The Future of Coal: Options for a Carbon-Constrained World. An Interdisciplinary MIT Study, Cambridge, MA. Kerr, Thomas M., 2008. Carbon dioxide capture and storage priorities for development. Carbon and Climate Law Review 2 (4), 335–338. Logan, Jeffrey, Venezia, John, Larsen, Kate, 2007. Opportunities and challenges for carbon capture and sequestration. WRI Issue Brief 1, 1–8. Markusson, Nils, Haszeldine, Stuart, 2008. How Ready is ‘Capture Ready?—Preparing the UK Power Sector for Carbon Capture and Storage. Scottish Centre for Carbon Storage, Glasgow. Miller, Peter D., 1979. Stability, Diversity, and Equity: A Comparison of Coal, Oil Shale, and Synfuels. In: Unseld, Charles T., Morrison, Denton E., Sills, David L., Wolf, C.P. (Eds.), Sociopolitical Effects of Energy Use and Policy. National Academy of Sciences, 1979, Washington, DC, pp. 167–186.
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Miranda, Marta, 2004. Mining and Critical Ecosystems: Mapping the Risks. World Resources Institute, Washington, DC. Nordhaus, Robert R., Pitlick, Emily, 2009. Carbon dioxide pipeline regulation. Energy Law Journal 30, 85–102. Page, S.C., Williamson, A.G., Mason, I.G., 2009. Carbon capture and storage: fundamental thermodynamics and current technology. Energy Policy 37 (9), 3314–3324. Palmer, et al., 2010. Mountaintop mining consequences. Science, 148–149. Radmacher, Dan, 2008. Effort to clean coal’s image won’t work. Roanoke Times 21, 7. Schiermeier, Quirin, Tollefson, Jeff, Scully, Tony, Witze, Alexandra, Morton, Oliver, 2008. Electricity without carbon. Nature 454, 821–828. Schreiber, A., Zapp, P., Markewitz, P., Vogele, S., 2010. Environmental analysis of a German strategy for carbon capture and storage of coal power plants. Energy Policy 38, 7873–7883. SigmonJr., S., William, L., 2008. Fossil and Hydro Generation in the Energy Industry. William and Mary Law and Policy Review Annual SymposiumFossil and Hydro Generation in the Energy Industry. William and Mary Law and Policy Review Annual Symposium. Sobin, Rodney, 2007. Energy myth seven: renewable energy systems could never meet growing electricity demand in America. In: Sovacool, B.K., Brown, M.A. (Eds.), Energy and American Society—Thirteen Myths. Springer, New York, pp. 171–199. Sovacool, B.K., 2008. Renewable energy: economically sound, politically difficult. Electricity Journal 21 (5), 18–29. Sovacool, B.K., Brown, M.A., 2009. Competing Dimension of Energy Security: An International Perspective. Working Paper Series. Working Paper #45. School of Public Policy, Georgia Institute of Technology.
Sovacool, B.K., 2009. Running on empty: the electricity-water nexus and the U.S. electric utility sector. Energy Law Journal 30 (1), 11–51. Sovacool, B.K., Sovacool, K.E., 2009a. Identifying future electricity water tradeoffs in the United States. Energy Policy 37 (7), 2763–2773. Sovacool, B.K., Sovacool, K.E., 2009b. Preventing national electricity-water crisis areas in the United States. Columbia Journal of Environmental Law 34 (2), 333–393. Sovacool, B.K., Brown., M.A., 2010. Competing dimensions of energy security: an international review. Annual Review of Environment and Resources 35, 77–108. Spreng, Daniel, Marland, Gregg, Weinberg, Alvin M., 2007. CO2 capture and storage: another Faustian bargain? Energy Policy 35, 850–854. Sundqvist, T., Soderholm, S., 2002. Valuing the environmental impacts of electricity generation: a critical survey. Journal of Energy Literature 8, 1–18. Sundqvist, T., 2004. What causes the disparity of electricity externality estimates? Energy Policy 32, 1753–1766. Tulloh, Brian, 2007. Letters from readers. EnergyBiz Insider. United States Agency for International Development, 2007. Designing a Cleaner Future for Coal: Solutions for Asia that Address Climate Change. USAID, Washington, DC. U.S. Government Accountability Office, 2008. Mine Safety: Additional Guidance and Oversight of Mines’ Emergency Response Plans Would Improve the Safety of Underground Coal Miners. Washington, DC: U.S. GAO-08-424. April, 2008. World Wildlife Foundation, 2007. Coming Clean: The Truth and Future of Coal in the Asia Pacific. WWF, Washington, DC.
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From a hard place to a rock: Questioning the energy security of a coal-based economy Benjamin K. Sovacool a,*, Christopher Cooper b, Patrick Parenteau c a Centre on Asia and Globalisation, Lee Kuan Yew School of Public Policy, National University of Singapore, Oei Tiong Ham Building, 469C Bukit Timah Road, Singapore 259772, Singapore b Institute for Energy and Environment, Vermont Law School, Royalton, VT, USA c Environmental and Natural Resources Law Clinic, Vermont Law School, Royalton, VT, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 10 April 2011 Accepted 27 April 2011 Available online 11 May 2011
We thank Brathwaite et al. for starting a very useful debate about what role, if any, coal should play in future energy transitions. Expanding upon their piece, we question that a coal-based economy, in which energy production for both electricity and transport comes from coal, can meet the energy security needs of the United States and other countries. & 2011 Elsevier Ltd. All rights reserved.
Keywords: Clean coal Carbon capture and sequestration Coal-to-liquids
1. Introduction ‘‘Frosty the Coalman, he’s getting cleaner every day. He’s affordable and adorable and the workers keep their pay. He’s abundant here in America, And he helps our economy rolly’’ The Clean Coal Carolers
Concerned about coal’s negative image during the Holiday Season, in 2008, the American Coalition for Clean Coal Electricity sponsored a multi-million dollar advertising campaign designed to coopt Christmas in the name of commerce. The campaign featured singing lumps of coal called ‘‘The Clean Coal Carolers’’ merrily crooning the benefits of ‘‘clean’’ coal (Radmacher, 2008). While not quite as entertaining as operatic anthracite, we still enjoyed reading Brathwaite et al.’s (2010) article on the transition to a coal-based economy. It contends, among other arguments, that moving away from an energy economy based on oil to one based primarily on coal could bring the United States many benefits. Brathwaite et al. tell us that coal is abundant, stable in price, and capable of reducing U.S. dependence on imported oil. As the authors remark (pp. 6086–6085), ‘‘coal-to-liquid fuels are attractive due to the vast reserves (over 200 billion short tons of the demonstrated reserve coal base) available for mining;’’ ‘‘due
n
DOI of original article: 10.1016/j.enpol.2011.04.069 Corresponding author. Tel.: þ65 6516 7501; fax: þ 65 6468 4186. E-mail address: [email protected] (B.K. Sovacool).
0301-4215/$ - see front matter & 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.enpol.2011.04.065
to the nature of coal mining and the political stability of major coal mining nations, the prices for coal are more stable than the prices for natural gas or oil;’’ and ‘‘a transition to a coal economy is desirable to reduce the dependence on foreign oil supplies.’’ The article also points out some of the constraints to a coal-to-liquids strategy, namely the fact that refining coal into gasoline is much less efficient than the conversion process for petroleum and that both coal and oil take millions of years to replenish. We appreciate, as well, that the authors engage some of our own recent work on energy security (Sovacool and Brown, 2009, later published in Sovacool and Brown, 2010). However, Braithwaite and her colleague’s assessment of the benefits and barriers to a coal economy is incomplete; it focuses primarily on coal use in the transport sector, and also only in a limited way addresses coal’s impact on energy security, affordability, availability, efficiency, and stewardship. Expanding upon their piece, we question that a coal-based economy, one in which energy production for both electricity and transport comes primarily from coal, can meet the comprehensive energy security needs of the United States and other countries. To clarify, we understand ‘‘clean coal’’ to refer to a collection of four technologies and processes: (a) supercritical pulverized coal plants that boost thermal efficiency by operating at higher temperatures, (b) integrated gasification combined cycle (IGCC) plants that use chemical processes to gasify coal and remove sulfur and mercury, (c) pressurized fluid bed combustion plants that use elevated pressure to capture sulfur dioxide and nitrogen oxides, and (d) carbon capture and storage (CCS) techniques such as deep underground geologic formations that are engineered to
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Table 1 Four criteria of energy security. Criteria
Underlying values
Explanation
Availability
Independence and diversification
Diversifying the fuels used to provide energy services as well as the location of facilities using those fuels, promoting energy systems that can recover quickly from attack or disruption, operating a reliable system, and minimizing dependence on foreign suppliers Providing energy services that are affordable for consumers and minimizing price volatility Improving the performance of energy equipment and altering consumer behavior Protecting the natural environment, communities and future generations
Affordability Equity
Efficiency
Innovation and consumer education
Stewardship Social and environmental sustainability
capture and store excess CO2 (Logan et al., 2007).1 By coal-toliquids (CTL), we mean fuels produced by the Fischer–Tropsch process, a gas-to-liquid conversion technique that uses a catalyzed chemical reaction to heat coal and transform the resulting carbon monoxide and hydrogen into a colorless, odorless fuel that can supply any engine that can operate on diesel fuel. We conceptualize a ‘‘coal-based economy’’ as relying almost exclusively on coal with CCS for electricity generation, and transportation fueled by CTL. Drawing from Sovacool and Brown (2010), we concur that energy security consists of the four criteria listed in Table 1. We begin by discussing the efficiency implications of a coal-based economy before assessing affordability, availability, dependence, and sustainability.
2. Efficiency implications Perhaps the most significant way in which a coal-based economy would be energy inefficient involves conversion inefficiencies for both CCS and CTL. CCS and CTL are approaches which ignore consumer efficiency and demand side management, and both accrue significant energy penalties. The International Energy Agency (2009) has noted that, for instance, CCS requires a substantial amount of heat and complex processes such as amine solvent regeneration and flue gas pre-treatments, which when combined with the need for auxiliary power, blowers, pumps, and compressors, reduces the operating efficiency of a coal power plant by 8% to 10%. According to the IPCC (2005), widespread adoption of CCS could erase the energy efficiency gains made in the last fifty years and increase coal consumption by one-third. Even then, actual capture rates are not perfect, with 15% of carbon 1 Almost all clean coal technologies rely on a four-step process of capturing, storing, transporting, and sequestering CO2. The ‘‘capture’’ stage requires separating CO2 from emissions and exhaust into pure waste streams, then pressurizing it for transport. While effective at preventing carbon from escaping directly into the atmosphere, capturing creates serious tradeoffs in operating efficiency. The easiest way to capture CO2 is to ‘‘scrub’’ it from the flue or exhaust gas using a chemicallike amine to extract the greenhouse gas. But this process entails a significant energy penalty. Carbon capture and storage involves capturing CO2 from coal-fired power plants and other fossil-fuel sources, condensing it, transporting it, and injecting it deep (4800 m) underground into secure geologic formations, and closely monitoring it to make sure it stays put for centuries. Though CCS technology has been used in many small scale projects around the world, mainly for secondary recovery in natural gas and oil fields, it has not been demonstrated at anywhere near the scale that would be required to permanently store all the CO2 from the burning of coal and other fossil fuels at projected rates of energy consumption.
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dioxide escaping into the environment (International Energy Agency, 2009: p. 13). Moreover, Page et al. (2009) found a disturbing discrepancy between simulated energy efficiency penalties for CCS plants reported by vendors and the plants’ actual operating performance. The reported efficiencies were 8–15.4%, but resulted mostly from process simulations. A vast majority of these simulations were not published in reputable journals but in ‘‘gray’’ literature, publications from governments and industry that have no independent peer review or check on quality assurance. The researchers also found considerable cross referencing of conference papers as primary sources, and reliance on data from only the three sites at Sleipner, Salah, and Weburn (which the authors even cautioned as inadequate). Such sites are very small, storing only 3–4 million tons of CO2 per year, compared with 8 billion tons emitted annually from coal and the 50 billion tons from all sources of greenhouse gas emissions per year. Because much of the CO2 stored at these sites did not come from power plants themselves but were derived from natural gas processing, performance calculations did not include power losses that would occur related to steam diversion in the separation process at actual CCS facilities. Page et al. warned that such information contrasts sharply with data from a ‘‘real world scenario’’ where considerable energy losses would be required to capture, compress, transport, and store CO2. Their calculations suggest energy penalties between 43.5% and 48.6% (depending on whether CO2 was liquefied or compressed), which are almost twice as large as projections from the industry. As the authors concluded, ‘‘CCS is not presently a near-term measure for mitigating greenhouse gas emissions y In light of the tension between the current status of CCS and the need for rapid and deep emissions contractions y the value of further investment in CCS must be seriously questioned’’ (Page et al., 2009: p. 9). Many of the efficiency challenges to CCS identified by Page et al. have been confirmed by attempts to build such plants in practice. While defending TXU Energy’s plan to build 11 new coalfired units in Texas, instead of newer CCS systems, one TXU vice president noted: IGCC is a promising technology, but is not yet viable on a largescale commercial basis for the types of coal available in Texas. There are only two IGCC units in operation today in the U.S.—both are small, were heavily subsidized, and actually have dirtier emission profiles than the supercritical plants we have proposed. Further, both these plants continue to operate at low reliability levels more than five years after coming on line (Tulloh, 2007). One assessment of the 15 integrated gasification combined cycle (IGCC) power plants operating around the world since 1984 (without carbon sequestration) in Germany, Italy, Japan, Netherlands, Singapore, Spain, and the United States found that all were prone to a host of reliability issues including difficulties with maintenance, high sensitivity to the types of coal used, and frequent malfunctions with auxiliary systems. Given these problems, facilities in aggregate operated only 28.5% of the time, or operated for 35,000 h out of a potential 122,640 h (Franco and Diaz, 2009). To make matters worse, in many cases plants must capture, compress, transport, and store two to three tons of CO2 to offset every ton emitted. Sigmon (2008), a senior vice president at American Electric Power, estimated that, given the energy-intensive nature of carbon capture, his company would have to sequester two tons of carbon for every one ton emitted, at a cost of $40–$45 for every ton of carbon displaced.
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The technological and economic inefficiencies associated with coal-to-liquids conversion are even starker. In 2007, the National Petroleum Council (NPC) issued preliminary studies used to compile its report Facing the Hard Truths about Energy. In a study from NPC’s coal-to-liquids and gas subgroup, industry experts estimated the thermal efficiency of direct liquefaction of coal to be between 50% and 54% (Bellman et. al., 2007). This estimation, however, may be misleading. It appears the industry calculates thermal efficiency by comparing the heating value of the resulting liquid fuel to that of the energy value of the inputs. But direct liquefaction is a two-stage process, requiring hydrogen inputs during the first process and oxidizing inputs during the second. How the industry derives and accounts for all of the inputs involved in this calculation reveals it to be based on a domino-effect of various processes reminiscent of a Rube Goldberg contraption (which were not known for their efficiencies). The first stage in direct coal liquefaction is a thermal process that breaks down the structure of the coal. To prevent the coal from re-polymerizing, however, the process requires the injection of hydrogen at high pressures. According to the NPC report, plants can supply this hydrogen feedstock (though not the pressure) as a by-product of coal gasification (presumably occurring at the same facility). In coal gasification, high-purity oxidants are used to partially oxidize the carbon in the coal feedstock. These oxidants, however, are derived from cryogenic air separation, a process of splitting air into its constituent parts by distilling it at sub-freezing temperatures. Cryogenic air separation itself requires huge amounts of energy. Atmospheric air must be filtered to remove dust and then compressed, and it has to pass through plane fin heat exchangers before being injected (again under pressure) into a refrigerated cryogenic distillation column. The process of ‘‘directly’’ liquefying coal, then, requires a feedstock from an entirely different gasification procedure that itself depends on the by-product of a wholly separate cryogenic distillation process. Each step in this Goldbergian system consumes enormous amounts of direct and indirect energy, almost none of which appear to be accounted for in the input calculation of CTL thermal efficiencies. The calculation of CTL thermal efficiency also appears to assume an entire production system (air distillation, gasification, and liquefaction) built at each facility. In tacit acknowledgment of these assumptions, the NPC report admitted that CTL could amount to only 20% of the U.S. petroleum market under the most optimistic scenario. Under more realistic conditions, however, CTL’s market share falls to somewhere between 0% and 6% (Bellman et al., 2007).
3. Affordability and price implications A coal-based economy not only would be inefficient, it would be prohibitively expensive. The International Energy Agency (2009) calculates that capturing carbon dioxide from flue gas streams at coal- and gas-fired power plants would cost more than $50 million to capture less than 5 million cubic meters. Because of the energy penalties involved, a 2007 interdisciplinary study from the Massachusetts Institute of Technology (MIT) concluded that carbon capture and storage technologies would cost about $25 per ton of CO2 to capture and pressurize and another $5 per ton to transport and store (Katzer et al., 2007). If implemented widely, the MIT team calculated the carbon capture and storage technologies would almost double the cost of coal-fired power. More recently, Charles (2009) estimated that a carbon price of $60 per ton would be required to make CCS competitive.
A modern subcritical pulverized coal plant produced power at about 4.84 b/kW h in 2006. But the cost of generation jumps 70% (to 8.16 b/kW h) when accounting for carbon capture and sequestration. The MIT study also found that if all of the CO2 emitted from power plants in 2006 were transported for sequestration, the quantity would be three times the weight and one-third the volume of natural gas transported by the entire U.S. natural gas pipeline system annually. If just 60% of the CO2 emissions were to be captured and compressed in liquid form for geologic sequestration, the volume of liquid carbon per day would be equivalent to all of the oil currently consumed in the United States (equal to about 20 million barrels of oil per day). The researchers argued that no CO2 storage project is currently attuned to overcoming these problems, since every large-scale clean coal system would have unique, complex characteristics that make them ill suited for mass production. Nordhaus and Pitlick (2009) similarly calculated that at a large-scale CCS would require a pipeline network comparable in size to the entire existing natural gas infrastructure. Assuming natural gas pipelines cost $420,000 per mile and the country currently requires 1.4 million miles of them, constructing a new CCS pipeline network on this order could cost as much as $58 trillion! This estimate may even be conservative considering that CCS would need to be deployed at biomass and natural gas power plants, in the fuel transformation and gas processing sectors, and in emissions-intensive sectors such as cement, iron, steel, chemicals, and pulp and paper manufacturing (International Energy Agency, 2010a). Clean coal and CCS facilities are also prone to cost overruns and significant delays. The U.S. Department of Energy’s (DOE) FutureGen program is a case in point. Industry estimated that the program would have a net cost of $1.5 billion ($1.1 billion from the taxpayers); design would take 5 years, and initial operation would take another 5 years. The DOE withdrew funding in 2008 after the industry had spent twice as much as first estimated. Even then, the FutureGen plant was to incorporate IGCC with pre-combustion capture, unlike the vast majority of coal-fired power stations that require post-combustion capture. The newly restructured FutureGen, launched in 2009, has its first demonstration project targeted for 2015, allowing plenty of time for additional cost overruns and technical hurdles to arise (Page et al., 2009). Davison and Thambimuthu (2009) surveyed all of the other state-of-the-art carbon capture and storage facilities in 2009 and noted that, based on current technology, advanced clean coal plants required 15–45% more fuel compared to ordinary plants. These energy penalties result in an increased gross cost of electricity generation of 30–80%. A separate nonpartisan study commissioned by the DOE admitted that IGCC and CCS systems, due to their higher capital costs compared to conventional plants, would result in incremental increases in electricity generation costs of 36–81% (Committee on Climate Change Science and Technology Integration, 2009). Similarly, an interdisciplinary European research team looking at the performance of new CCS plants in Australia, China, France, Germany, India, Japan, Korea, United States, United Kingdom, and the Nordic countries estimated extra costs of US$20 to 95 per ton of carbon dioxide captured and sequestered, and cautioned that the average conversion efficiency of coal-fired power plants would continue to be low. Using the best state-of-the art technology, the researchers estimated that the best efficiencies these plants could achieve would be no better than 29–41% (InterAcademy Council, 2007: pp. 62–73). A separate European Commission study confirmed that European CCS facilities would likely see increases in the cost of power generation of 40–80% compared with conventional plants, with an energy penalty of 11–40% (European Renewable
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Energy Council, 2007). Moreover, the nonpartisan U.S. Congressional Budget Office (2007) surveyed the potential for CCS in the United States and found that CCS ‘‘had not yet been demonstrated’’ on the scale necessary to seriously mitigate emissions. They estimated that the price of a single ton of CO2 would have to be $15–90 before CCS power plants would become cost competitive with other energy generation. Even more disturbing, the report found that even if all known oil fields, geologic sites, aquifers, and depleted reservoirs were converted for CCS, it would be insufficient to meet U.S. carbon storage needs (though some other reports have shown differently). Incredibly, these problems are likely to get worse, not better, over time. Hansson and Bryngelsson (2009) looked at future projections of CCS costs, and found common assumptions that expenses would decrease over time due to learning and experience were wrong. Instead, after surveying a large number of experts in the field, they found that costs likely would go up due to ‘‘negative learning’’ and the risk of leakage. By their calculations, even an annual global leakage rate of 0.5%, excellent in terms of operational efficiency, would be completely unacceptable for climate change mitigation. To successfully address climate change, systems would need to achieve perfection, which even American football coach Vince Lombardi admitted was unattainable. Other studies have spotlighted the need for further research to improve carbon transport and storage phases, system integration, and the retrofitting of old plants before CCS is ready for any type of commercialization. Significant research entails significant added cost (Markusson and Haszeldine, 2008). The International Energy Agency (2010b) reports that a minimum of $36.1 billion in research funds will need to be spent on demonstration projects before engineers can determine whether such plants can even function in the real world. Perhaps this explains why an assessment in Nature also concluded that ‘‘the probability of carbon capture and storage being widespread in 10 or even 20 years is very low’’ (Schiermeier et al., 2008: 822).
4. Availability and dependence implications Brathwaite et al. (2010) note that the abundance of coal in the United States makes it likely that reserves will not be depleted until ‘‘well beyond’’ 2100, and that coal-fired electricity is a ‘‘mature industry’’ with more than a century of experience generating electricity. However, though coal is abundant in the United States, it is scarce globally. Indeed, 80% of the world’s coal can be found in just 8 countries. In Germany, Schreiber et al. (2010) note that because CCS and clean coal technologies are less efficient (and would require greater amounts of coal imports), their use can significantly increase the country’s dependence on coal imports. They projected that Germany would require 50 million tons of additional lignite if the country embarks upon a CCS path compared to relying on coal without CCS. So for countries beyond the United States, CCS could only increase import dependence and costs. Moreover, even if the fuel for coal were widely available, CCS technology is not. Florini and Sovacool (2011) have documented how the United States and other European countries have refused to distribute clean coal technology to countries such as China or India out of intellectual property concerns. The United States Agency for International Development (2007) surveyed prospects for clean coal development in China, India, Indonesia, Philippines, Thailand, and Vietnam, and found little incentive for these countries to rehabilitate, retrofit, upgrade, or improve coal-fired power stations. This was partly due to the difficulty of acquiring CCS technology, and partly due to the perception that such technologies were costly, unproven, and risky.
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5. Stewardship and sustainability Brathwaite et al. (2010) do acknowledge that coal has numerous social and environmental externalities, but dedicate only a few sentences to this claim. The Department of Trade and Industry in the United Kingdom (2010) recently noted that power plants with CCS will ‘‘increase [GHG] emissions and air pollutants per unit of net delivered power and will increase all ecological, land-use, air-pollution, and water-pollution impacts from coal mining, transport, and processing, because the CCS system requires 25% more energy, thus 25% more coal combustion, than does a system without CCS.’’ Indeed, even with capture and storage coal is likely the dirtiest of all energy systems. Thomas Sundqvist and Patrik Soderholm analyzed as many externality estimates they could find (132 in all) to determine the extent that fossil fuels, nuclear power, and renewable energy systems imposed unpriced damages on society (Sundqvist and Soherholm, 2002; Sundqvist, 2004). They found that net costs (negative externalities outweighed positive ones) ranged from a low of 0 b/kW h to a high of almost 73 b/kW h for various technologies, with a mean of 15 b/kW h for coal, making it the largest (e.g, the most damaging) of all sources depicted in Fig. 1. When updated to $2007, coal generation created $228 billion in additional costs and damages in the United States alone for that year (Sovacool, 2008). Harvard Medical School (2011) researchers recently determined that the lifecycle impacts of coal and its waste stream cost the U.S. public as much as $500 billion annually. These figures cannot capture many of the deleterious impacts from coal that defy easy measurement. For example, greater reliance on CCS and CTL would mean that mining accidents and black lung disease would kill more coal miners every year. Mountaintop removal mining would devastate Appalachian watersheds. Acid rain would destroy alpine lakes and boreal forests. Mercury would contaminate an increasing number of aquatic ecosystems and fisheries. More national parks would be shrouded in haze. More toxic chemicals would leach from combustion waste facilities and pollute groundwater and drinking water supplies. Fine particulates and other contaminants in soot and smog would increase rates of human mortality and morbidity. In short, coal would sustain its place as arguably the dirtiest, most dangerous, and most ecologically destructive source of energy on the planet. No matter what happens upstream at the coal plant or CCS facility, coal extraction and processing will still greatly affect the quality of water and land resources, and coal will still need to be
20 18 16 14 12 10 8 6 4 2 0
Fig. 1. Environmental externalities associated with electricity generation technologies (2007 U.S. Cents/kW h). Source: Sovacool (2008).
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transported. Because CCS systems exact an energy penalty, they will require more coal to produce each unit of electricity, exacerbating all of these downstream impacts (Boute, 2008). Failing coal slurry impoundments, saline pollution from coal-bed methane recovery, and occupational safety and health hazards (including mine-related deaths) are also among the other impacts of continued reliance on coal-fired electricity production (Sobin, 2007). The most visible environmental impact is coal mining. Of more than one billion tons of coal mined in the United States annually, roughly 70% comes from surface mines. Mountaintop removal (a newer technique for mining coal that uses heavy explosives to blast away the tops of mountains) has destroyed streams, blighted landscapes, and diminished the water quality of rural communities. Palmer et al. (2010) have argued that the impacts of mountaintop removal ‘‘are pervasive and long lasting and there is no evidence that any mitigation practices successfully reverse the damage it causes.’’ One estimate calculated that mountaintop removal has destroyed 1.5 million acres of hardwood deciduous forests and 500 mountains in the Eastern part of the United States alone (Biggers, 2009). Underground coal mining, responsible for the remaining 30% of mining in the U.S. and most mining worldwide, remains a highly dangerous industry. Underground coal miners must confront highly explosive methane gas, geological conditions that make mine roofs notoriously unstable, the ever present dangers posed by fire, and flooding from nearby abandoned mines. Twelve miners lost their lives in 2006 at the Sago mine in West Virginia after an explosion forced them to barricade themselves in the mine to await a two day rescue. The episode was a stark reminder that miners do not escape these risks even in the highly regulated U.S. coal mining sector. The U.S. Government Accountability Office (2008) has warned that, despite new legislation, many mines still operate in violation of safety standards. In some districts in West Virginia and Kentucky, two-thirds of mines have been issued citations for not complying with federal standards. Globally, coal mining activities have taken their toll on local environments and communities. Exploration activities involve drilling and vegetation clearing, trench blasting, and geophysical surveying that can result in habitat loss, sedimentation, and deforestation due to road development. Site preparation has been shown to fragment ecosystems, increase demand for water resources, change predation rates, and accelerate the chemical contamination of land. Mining operations require supporting infrastructure, such as roads, electricity, processing facilities, and ports. Once closed, abandoned mines pose dangers such as physical injury, persistent contaminants in surface and groundwater, and acid drainage affecting hundreds of thousands of streams (Miranda, 2004). Mining’s social impacts can be just as grave. One assessment of the global mining industry identified many coal mines located in communities plagued by corruption, civil unrest, and lack of participation in civil society. The study warned that nearly onequarter of active mines and exploration sites are located in countries exhibiting the weakest governance structures (Miranda, 2004). These regimes also have the least stringent environmental controls. They rarely regulate or prohibit dumping and disposing of mine wastes. More than one-quarter of the world’s active mines overlap with or are within a 10 km radius of strictly protected areas or intact ecosystems of high conservation value; about one-third of all active mines are located in stressed watersheds; and one-fifth of active mines and exploration sites are in areas of high or very high seismic hazard. Coal mining also supports unstable and uneven development, with boom-and-bust cycles affecting mining towns and wide fluctuations in economic activity over a short timeframe (Miller, 1979).
Examples from China are most prominent. The Chinese coal sector employs 7.8 million people and produces about 40% of the world’s coal. Yet it accounts for 80% of the total deaths in coal mine accidents worldwide. In 2005 alone, according to official figures, Chinese mines recorded 3306 accidents and 4746 mining deaths in 2006 (WWF, 2007). Coal miners that survive the workplace face the risk of black lung disease (pneumoconiosis). China is already home to more than 600,000 black lung patients, with 1167 new cases and 163 deaths per year from the state-owned coal sector. Accounting for the depletion of arable soil, diminishing water supplies, severe air pollution leading to grave respiratory illness, displaced and disenfranchised communities, and coal mining accidents and deaths, the true cost of Chinese coal is estimated to be at least 56% higher than its market price (WWF, 2007). The safety and reliability of CCS sites is another serious concern. Storage of CO2 must be safe, cost-effective, and permanent if it is to become a viable climate mitigation strategy, yet sites would be subject to seismic dangers. Given the enormous amount of CO2 that must be stored, even a tiny amount of leakage could prove disastrous for the climate. To be a successful burial site, a geologic formation must be more than 1 km underground. That depth provides enough pressure to turn CO2 from a gas into a supercritical fluid, a form in which the CO2 is more likely to stay put. Ironically, however, the formation also has to be porous enough, with cracks and cavities to hold massive volumes of CO2. Lastly, it needs to be covered with a layer of non-porous rock to provide a leak-proof cap. Identifying sites that have the needed permanence, cost, and safety requirements is an enormously complicated issue, and considerable underground testing must occur before injection begins. The environmental and liability issues associated with merely finding and testing sequestration sites are challenging and unresolved (Kerr, 2008). Escaping CO2 can also kill people. One large bubble of CO2 released from a volcanic lake in Cameroon suffocated more than 1700 people in 1986. Blackford et al. (2009) have argued that even slow and chronic rather than abrupt and sudden leaks can poison marine environments, acidify seawater, and harm mussels, starfish, and urchins with ‘‘potentially severe’’ ecological impacts. Groundwater contamination can occur if stored CO2 leaks or unexpectedly migrates. CO2 injection can result in pressure buildup and increase seismic activity. Operational leakage to the surface can create a public health risk since high concentrations of CO2 can induce fatal asphyxia. Slow, sudden, or chronic releases of CO2 can to the surface can accelerate climate change. Environmental degradation can occur as sequestered CO2 leaks to the surface and impacts vegetation, trees, and soil composition (de Figueiredo, 2007). A final environmental concern is water. Court et al. (in press) have shown that a coal-fired power plant retrofitted for CCS requires twice as much cooling water as one without CCS. CTL fares even worse. While the total amount of water required for liquefaction depends on factors like plant design, coal properties, location, and humidity, on average liquefaction using advanced Fischer–Tropsch Technology requires approximately 5.0–7.3 gallons of water for every gallon of liquid fuel produced (Elcock, 2008). The water-intensity of a coal-based economy does not bode well for coal’s ability to address climate change concerns, especially when population growth, electricity demand, and summer heat seem likely to increase simultaneously throughout the United States. Some of our own published studies have noted that 22 counties and 20 large metropolitan areas in the U.S. could experience severe water shortages by 2025 (Sovacool, 2009; Sovacool and Sovacool, 2009a, b). Greater reliance on coal and other thermoelectric power plants could therefore deplete the water available from Lake Lanier in Georgia and exacerbate interstate litigation between Tennessee, Alabama, and Florida.
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Biodiversity could perish along the Catawba-Wateree River Basin in North Carolina. Chicago could find itself embroiled in domestic and international legal disputes over the consumption and withdrawal of water from Lake Michigan. Households and businesses could run out of water from the South Platte River in Colorado. Rivers could stop recharging the groundwater needed for drinking and irrigation in Texas. Lake Mead and the Colorado River could continue to suffer drought, drastically affecting the state of Nevada, inducing an agricultural crisis in California and Mexico. Fisheries along the Hudson River in New York could collapse. The Delta Smelt could become extinct in the San Joaquin River Basin in California. These impending but avertable risks serve an important reminder that climate change is not the only serious environmental issue affected by a coal-based energy economy.
6. Conclusion We thank Brathwaite et al. for bringing into focus some of the energy security concerns associated with a transition to CTL in the United States. Building from their work, our own assessment questions whether CCS and CTL can ever contribute positively to energy security within the United States and beyond. Because the myriad processes required to render coal safer and cleaner exact large energy conversion penalties, a transition to a coal-based economy would require vastly more coal to generate the same amount of energy. That means, even on a per unit basis, a coal-based economy will exacerbate the risks inherent in coal mining, processing, combustion, and clean-up. But transitioning to a coal-based economy will also require more actual units of energy to replace units currently supplied by oil, natural gas, and a plethora of other fuels. Thus, the coal’s economic, social, and environmental risks expand exponentially as it begins to replace other fuels. Then there is the matter of opportunity cost. In a world of scarce resources and only a few decades within which humanity has to address climate change, scaling up coal systems seems a dangerous waste of resources. We cannot afford to build out two huge energy infrastructures at the same time, nor can we achieve efficiency goals while building plants that must operate for 50 year to recoup investments. Coal pathways themselves raise energy security risks. For all industrial purposes, CCS remains largely unproven. When it does prove viable, it will require massive new capital costs and entail enormous long-term liabilities. Spreng et al. (2007) have noted that clean coal is similar to nuclear power in this respect. Like high level nuclear waste, CCS systems would need to carefully manage carbon dioxide for incredibly long periods of time. They would have to operate perfectly to achieve climate change goals and protect human health and the environment. Imagine the difficulty the International Atomic Energy Agency and Nuclear Regulatory Commission have in managing relatively small volumes of nuclear waste, and consider that the volume of carbon dioxide emitted into the atmosphere each year is in the billions of tons. Every aspect of a coal-based economy exacts greater external costs from the increased mining, transportation, processing and combusting of coal. Some of these costs will be reflected in higher energy costs, squeezing a burdened underclass and crippling an economy in tentative recovery. But many costs will not be reflected in energy prices. These include the increased deaths from coal mining, the increased morbidity and mortality associated with inhalation of particulates, the devastation of the sight and soul of rural mining communities, and the heightened competition over dwindling sources of potable water. In theory we may achieve the technological capability to transition from oil
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dependency to an independent coal-based economy. But, pursuing more CCS and CTL research and development risks delaying more durable measures and diverts resources from more effective alternatives like energy efficiency and renewable resources. In the end, the social, economic, and environmental costs of transitioning to a coal-based economy would continue to keep us somewhere between a rock and a hard place.
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