4-25

Table 4.3: Potential CO2 Emissions Reductions from Advanced Coal and Gas PoweSystems* (in millions of metric tons per year MMtpy) of carbon)

Gas

Increased incremental generation (billions of kWh/y) for each 5 year period (Table 8A of AEO 97)

Cumulative power generation from advanced gas systems:

Assuming all additions from 1996 to 2005 are 55 percent efficient systems Assuming all additions from 2006 to 2010 and 3/4 of the additions from 2011 to 2015 are 60 percent efficient systems

Assuming 1/4 of the additions from 2011 to 2015 are 70 percent efficient systems

Cumulative carbon dioxide emission reductions [millions of metric tons of C per year]:
Resulting from 55 percent efficiency plants
Resulting from 60 percent efficiency plants

Resulting from 70 percent efficiency plants

Total carbon emission reduction assuming advanced (55 to 70% efficiency) gas systems

Total carbon emission reduction assuming 55% efficiency natural gas combined-cycles used throughout the period

Carbon emission reductions resulting from 60 and 70% efficiency technologies compared to 55% efficiency technologies

Coal

Increased incremental generation (billions of kWh/y) for each 5 year period (Table 8A of AEO 97)

Cumulative power generation from advanced coal systems:

Assuming all additions from 1996 to 2005 are 42 percent efficient systems
Assuming all additions from 2006 to 2010 are 50 percent efficient systems
Assuming1⁄2 of all additions from 2011 to 2015 are 50 percent efficient systems

Cumulative carbon dioxide emission reductions [millions of metric tons of C per year):

Resulting from 42 percent efficiency plants

Resulting from 50 percent efficiency plants

Resulting from 60 percent efficiency plants

Total carbon emission reduction due to advanced coal systems

⚫ Emission reduction estimates are relative to the average carbon emissions (0.246 kgC/kWh) from fossil generation in 1995, as reported in AEO 97.

For example, 156 billion kWh/y is the difference in power generation rate due to new gas capacity between 1996 and 2000. Alternatively, if the comparison is to a gas turbine with the average efficiency of the current fleet (-36%), the reduction due to advanced combined cycles of 55 to 70% efficiency is about 50MMtpy in 2015.

It should be noted that if advanced combined cycle gas power at 60% and 70% efficiency is compared to the best current gas combined cycle of 55% efficiency, the reduction in emissions from the efficiency improvement in gas power is only about 4 MMtpy by 2015. This indicates the diminishing returns due to more efficient gas systems.

REFERENCES

Collett 1993: T. S. Collett, Natural Gas Production from Arctic Gas Hydrates, USGS Professional Paper 1570, p. 294.

EIA 1996: Energy Information Administration, U.S. Department of Energy, International Energy Outlook 1996, (Washington, DC: U.S. Government Printing Office, DOE/EIA-0484(96), May 1996).

EIA 1997: Energy Information Administration, U.S. Department of Energy, Energy Information Administration Annual Energy Outlook for 1997 (Washington, DC: U.S. Government Printing Office DOE/EIA-0383(97), December 1996.)

FE 1995: Office of Fossil Energy, U. S. Department of Energy, Natural Gas Strategic Plan, DOE/FE-0338, June 1995.

FE 1997a: Office of Fossil Energy, U.S. Department of Energy, Clean Coal Technology Demonstration Program: Program Update 1996 June 1997.

FE 1997b: Office of Fossil Energy, U.S. Department of Energy, Coal and Power Systems R&D Programs, July 1997.

FE 1997c: Office of Fossil Energy, U.S. Department of Energy Oil and Gas R&D Programs,March 1997.

Gibbons 1996: John H. Gibbons, Assistant to the President for Science and Technology, Science and Government Report 26(17), November 1, 1996

Gray and Tomlinson 1997: David L. Gray and Glen Tomlinson, Fischer-Tropsch Fuels from Coal and Natural Gas: Carbon Emissions Implications, (McLean, VA:Mitretek Systems, August 1997.

Greene and Leiby (1993): D. L. Greene and P. N. Leiby, The Social Costs to the U. S. of Monopolization of the World Oil Market, 1972-1991, (Oak Ridge, TN: Oak Ridge National Laboratory, ORNL-6744, 1993). Greene, Jones and Leiby (1995): D. L. Greene, D. W. Jones, and P. N. Leiby, The Outlook for U. S. Oil Dependence, (Oak Ridge, TN: Oak Ridge National Laboratory, ORNL-6873, 1995.

Herzog et al. 1997: H. Herzog, E. Drake, and E. Adams, CO2 Capture, Reuse, and Storage Technologies for Mitigating Global Climate Change, Department of Energy Report DE-AF22-96PC01257, January 1997. Hileman 1997: Bette Hileman, "Fossil Fuels in a Greenhouse World," C&EN 75, pp.34-37, August 18, 1997.

Kvenvolden 1993: K. A. Kvenvolden, "Gas Hydrates as a Potential Energy Resource-A Review of Their Methane Content," in The Future of Energy Gases, D. G. Howell et al., eds., USGS Professional Paper 1570, pp. 555-561.

Senate 1997: Senate Committee on Appropriations Report on H. R. 2107, Department of the Interior and Related Agencies Appropriations Bill, 1998 July 1997.

Serchuk and Means 1997: Adam Serchuk and Robert Means, Natural Gas: Bridge to a Renewable Energy

Future, Issue Brief #8, Renewable Energy Policy Project, May 1997.

Socolow 1997: Robert Socolow, ed., Fuels Decarbonization and Carbon Sequestration: Report of a Workshop (Princeton, NJ: Princeton University Press, PU-CEES Report No. 302, September 1997).

Williams 1996: R. H. Williams, Fuel Decarbonization for Fuel Cell Applications and Sequestration of Separated CO2 (Princeton, NJ: Princeton University Press, PU-CEES Report 295, 1996).

CHAPTER 5

NUCLEAR ENERGY: FISSION AND FUSION

Many of the technologies that will help us to meet the new air quality standards in America can
also help to address climate change.

President Bill Clinton'

Two distinct processes involving the nuclei of atoms can be harnessed, in principle, for energy production: fission-the splitting of a nucleus-and fusion-the joining together of two nuclei. For any given mass or volume of fuel, nuclear processes generate more energy than can be produced through any other fuel-based approach. Another attractive feature of these energy-producing reactions is that they do not produce greenhouse gases (GHG) or other forms of air pollution directly. In the case of nuclear fission a mature though controversial energy technology-electricity is generated from the energy released when heavy nuclei break apart. In the case of nuclear fusion, much work remains in the quest to sustain the fusion reactions and then to design and build practical fusion power plants. Fusion's fuel is abundant, namely, light atoms such as the isotopes of hydrogen, and essentially limitless. The most optimistic timetable for fusion development is half a century, because of the extraordinary scientific and engineering challenges involved, but fusion's benefits are so globally attractive that fusion R&D is an important component of today's energy R&D portfolio internationally.

Fission power currently provides about 17 percent of the world's electric power. As of December 1996, 442 nuclear power reactors were operating in 30 countries, and 36 more plants were under construction. If fossil plants were used to produce the amount of electricity generated by these nuclear plants, more than an additional 300 million metric tons of carbon would be emitted each year.

Worldwide, 15 countries obtain at least 30 percent of their electricity from nuclear fission power. In 1996, among countries of the Organization for Economic Cooperation and Development (OECD), nuclear power provided 77 percent of the electricity in France, 33 percent in Japan, 26 percent in the United Kingdom, and 20 percent in the United States. The United States has the largest number of operating nuclear reactors (109) and the largest nuclear capacity (about 100,000 MW) of any nation. Nuclear fission power is a widely used technology with the potential for further growth, particularly in Asia.

2

President Bill Clinton, Address to the United Nations Environmental Conference, 26 June 1997.

Fission energy has a vocabulary that is well established in both technical and popular communication: It has adopted "nuclear" as its own. In this report, “nuclear power," "nuclear plants," and other uses of the word "nuclear," when applied to existing energy generation capability, refer to nuclear fission only. As nuclear fusion has not achieved that state of development, there should be no confusion.