Power plants in the U.S. burned more than one billion tons of coal in 2006, according to the U.S. Department of Energy's Energy Information Administration. Nearly 400 million of those tons came from the region known as Appalachia, a swath of territory stretching along the spine of the Appalachian mountains from southern New York State to northern Mississippi. These ancient mountains hold high-quality bituminous coal, which fuels the aging coal-fired power plants that supply roughly 50 percent of the nation's electricity and more than 40 percent of the nation's emissions of carbon dioxide—the leading greenhouse gas. As a result, mountains are being leveled to get at the coal that lies below them, clearing forests, polluting streams and destroying the health of local residents. And, according to the most recent report of the Intergovernmental Panel on Climate Change (IPCC), this state of affairs is likely to continue as the U.S. and the world continue to burn coal for electricity.

"Certainly for the next several decades, the majority of electricity will be generated by fossil fuels in a fairly conventional way," says Bill Moomaw, an international energy policy expert at Tufts University's Fletcher School of Law and Diplomacy, primarily because it is cheap and readily available. "If we're going to continue to use coal we're going to have to have some way of reducing the carbon dioxide." As a result, the IPCC summary notes that carbon capture and storage—trapping the carbon dioxide before it escapes from the smokestack and pumping it underground—is a likely technology solution for mitigating climate change, along with a variety of other options. "There is no silver bullet," says Harlan Watson, senior climate negotiator for the U.S.

But carbon capture and storage will play a key role as coal continues to supply a significant portion of world energy supply and, unfortunately, it has yet to be demonstrated on any power plant anywhere. The U.S. Department of Energy (DOE) has at least 20 pilot projects to investigate it, according to Stephen Eule, DOE's director of the climate change technology program, but none have applied it on a commercial scale. A variety of techniques, including passing the remnants of coal combustion through an ammonium carbonate solution or separating purified CO₂ from gasified coal, are possible—at a cost. "There is no plant that integrates gasification with capture and sequestration," says physicist Ernest Moniz of the Massachusetts Institute of Technology, who co-chaired a report on the future of coal. But "gasification looks today to be the lowest cost option with carbon capture."

That primary cost is in energy that gets used to capture the carbon—roughly 40 percent of the power a plant can produce—as well as to pressurize it and pump it underground. "In general terms, you are talking about a 50 percent increase in the cost of coal and maybe a 25 percent increase in the retail residential price of coal-fired electricity," Moniz says. "For a 600-megawatt power plant, in order to capture most of the CO₂ and sequester it for the 50-year life of the plant, you're talking about one billion barrels of supercritical CO₂. That's a pretty big reservoir."

And, although a few projects such as the Sleipner gas field in the North Sea or oil fields owned by the EnCana Corporation in Calgary, Alberta have proved that CO₂ can be pumped underground and remain trapped below cap rock, they are aimed at enhancing recovery of the fossil fuels in those fields rather than permanently storing the greenhouse gas. "There's a high likelihood that if you choose your site well it will hold CO₂ for hundreds of thousands of years," says S. Julio Friedmann, head of the carbon management program at Lawrence Livermore National Laboratory in California.

There are other technologies available, such as using algae to capture the waste greenhouse gases from power plants and turning it into diesel or other fuels. "The amount of CO₂ that you capture [with algae] is very high and the amount of biofuel created per acre is incredibly greater than you can do with corn or even sugarcane," Tufts's Moomaw says. "The problem is it only works in the daytime." Alternative forms of power production, such as wind or solar, remain a small—albeit fast-growing—portion of world electricity supply. Even nuclear power is unlikely to play a major role in fighting climate change. "By 2030, we might be seeing something around 18 percent of power being generated by nuclear rather than the 16 percent we see today," Moomaw adds. "There are so many issues around nuclear power, we don't see it as being the answer to global warming and the electricity sector."

4 Comments

1. 1. David M. Clemen 02:11 AM 2/22/08

   I have worked in the Hydroelectric industry as a senior electrical engineer for more than 22 years (now retired). I am always amazed that an industry that produces as much electrical energy as nuclear on a worldwide basis , and is truly renewable, receives such little coverage when energy sources are discussed. Hydro and Nuclear each produce 17% of the world's electrical power - Reference Scientific American Special Issue, Sept 2006, P.87 & HRW magazine, July 2006, Editorial
   
   A number of points made in the various articles published in the Tribune are concerned with better energy efficiency for the devices utilizing electrical energy. A point that was not made, and which should be addressed, is the energy efficiency of the power plants in the overall energy scheme. Fossil fueled plants are in the order of 50% efficiency when converting chemical energy to heat energy (Reference Mark's Standard Handbook for Mechanical Engineers, 8th edition, 1979, Chapter 9, Sources of Energy, P. 9-152). If the turbine generator conversion efficiencies are included, the total energy conversion process is less than 50%. The maximum energy conversion efficiency from wind to electrical energy is in the range of 40 - 45%. The maximum energy conversion efficiency from water to electrical energy is in the range of 80 to 85%. Therefore, Hydroelectric power plants utilize the most efficient energy conversion process; and hydroelectric power is also a "renewable" energy source (zero emissions).

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2. 2. Wylde Brumby 07:14 AM 3/20/08

   Solutions to energy generation have, up to now, only considered separating out functions.
   
   I envision the sewerage works of the future burning methane for energy with stirling engines to capture waste heat and algae that produce biodiesel grown in the hot water and enriched carbon dioxide atmosphere. After the algae has been pressed to squeeze the oil, it could be used as a feed supplement for cows, goats, etc - diversifying profits for utilities.
   
   Cars being built as hybrid vehicles could utilise Brazil's flex-fuel tech and have solar panels and a battery to use each type of dominant energy when available.
   
   I would construct "aeolian hydro" on a neighbourhood level to assist with a "base load". How this works is a vertical turbine turns an Archimedes' Screw to lift water from a pond into a elevated storage tank. When excess power is needed this small scale hydro facility could feed power into the grid - it converts intermittent wind power into a more dependable resource that doesn't consume power to store energy for later release.

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3. 3. scolio147 01:26 PM 1/7/11

   Thank you for this educational insight. I believe coal is a great fuel and heat source but the smoke it gives off is not so great. As well as it is a limited source I think it should be preserved. At least with electrical power it is renewable. http://www.seltrekelectricalsolutions.ca
   

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4. 4. geartrust 03:04 PM 2/27/13

   How do you will stop climate changing? We have only one way with customer’s investment to avoid production and selling new green machines for renewal energy, transportation, machine tools etc those require to wait reduced emissions too long time. There is directly or indirectly to reduce machines energy consumption and emissions soon as possible because it is advantage for both manufacture, customers and opens additional high-paid jobs for economy growth. There are transformation of existing propulsion: (1) existing transmission is replaced by state-of-the-art gearbox apparatus that eliminates to use the gas or magnetic field acceleration and uses only highest torque or idle speed of motor shaft, (2) gearbox apparatus is installed in propulsion that have ignored using gear-transmission and is huge motor, (3) replace existing motor by motor with reduced power and cost in many times. What are arguments?
   In the past, lower technical progress, global communication, education levels and few numbers of vehicles and other machines comprising the propulsion that such directly eliminate transmissions or indirectly their function of saving energy according to four too old traditions:
   I. It has unnecessarily increased motor power in up to hundred times today since chosen steam, gas or magnet field as lever for acceleration of many thousand pounds of vehicle and other machine/part
   II. It uses the transmission as second brake to acceleration system to result of wasting up to 80% mechanical energy in form of motor heat.
   III. Propulsion of lightweight vehicle uses “automatic transmission of torque converter” or “continuously variable transmission” that works as clutch that requires to increase power of motor exceed motor power of 80,000 lbs heavy-duty truck in comparison their weights (3,000 lbs) with highest loads.
   IV. Machine propulsion is only motor jointed to wheels or propeller, or spindle etc. This design directly ignores the Creator’s Physics Laws of Lever and Inertia for saving energy.
   May be engine with increased diameter or number of cylinders more save energy? This is not true. The potato cannon use the basic principle. Therefore, increasing physical cylinder volume or its number of engine or wire length of electric motor is increasing its gas of electric consumption plus the excessive unknown consumption by gas or magnet field acceleration system.
   
   How do we protect our health, life, stop climate changing, and prevent volcanoes awaking without vehicle production delaying? The Archimedes (circa 287-212) said: “Give me a point of support and I will turn around the Earth by a lever”. May be Archimedes is not relevant? This can be easily examined. A shift gearbox of nine shafts could increase the torque of motor shaft or its power up to 5x5x5x5x5x5x5x5=390,625 times and wastes only 2%x8=16% energy.
   Creator’s idea is non-accelerated vehicle and other machine propulsion comprising steel levers as is a state-of-the-art gearbox apparatus design is disclosed by two USA patents 8,011,274 at 09/06/2011 and 7,191,676 at 03/20/07. There are above 1,000 state-of-the-arts designs that provide advantage for both manufacture and customer (www.repowermachine.com):
   1. It comprising least numbers of gears and maybe shafts in the world today;
   2. It cuts energy consumption, emissions including the harmful gas - nitrate oxides (NOx) is by much lower interior temperature of engine condition, noise, power and cost of motor in many times and uses only maximum torque or idle speed for producing needed overdrive speeds and torques;
   3. It improves driver’s safety and comforts by switching manual regime to semi-automatic or/and automatic regimes by computer using;
   4. It could improve maneuverability: a) driver saves time by getting each speed without acceleration and uses many reverse speeds; b) it expands the range of speeds up to 272 forward/170 reverse overdrive speeds/torques by adding only 2 shafts to existing heavy-duty truck gearbox of 18 / 2 torques; c) driver uses front on uphill and rear on downhill, or all wheels temporarily for additional saving energy; d) aircraft or watercraft have much increased turning speed if uses it instead existing operation system.
   5. Its production uses the same machine tools and other items of existing manufacture.
   This innovation is finalist at Cleantech and Energy of 2012 Minnesota’s TEKNE AWARDS (see an article which appeared in 2012 Minnesota’s TEKNE AWARDS magazine).
   Next existing three transformed propulsion examples for understanding to reduce emissions and economy energy is no problem:
   1) Non-accelerated Volvo VGD heavy-duty truck has gearbox apparatus (3x2x2x2) of 24 forward/12 reverse torques/overdrive speeds by 18 gears/5 shafts or 40% gears number less to existing shift gearbox of 18 forward/2 reverse torques. It could reduce motor power in 4 times (500 hp to 123 hp). Driver of the long haul tracking saves above $25,000 per year if $3 fuel price.
   2) Chosen gearbox apparatus (3x4) with only 12 overdrive speeds/ 4 reverse by 16 gears/ 3 shafts replaces the existing transmission of the Jaguar XFR-S 2013 comprising 550 hp motor for acceleration it from 0 to 100 mph for 5 second by gas or magnet field because it is replaced by motor of 20 horse power that could reduce also up to power 0.75 horse power of the first steel vehicle motor of Carl Benz at January 29, 1886, Germany (patent #37435) if will choose gearbox apparatus that produces torques too. Driver of the Jaguar XFR-S 2013 types on computer maximum speed 300 mph and GAFEES moves it during 1(one) second from stop if its wheels and road have sufficient friction.
   3) An automatic programmed gearbox apparatus (2x2x2x2x2x2) of 64 torques/overdrive speeds by 32 gears/ 7 shafts that joined to Dayton motor 1/2 hp that reduce power in 10 times (5hp to 1/2hp) for reason to get non-accelerated CNC Knee Mill spindle. It has reduced CNC Knee Mill cost so that it is affordable by small businesses.
   

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