Figure 1. Reductions in carbon emissions from each scenario in the U.S.

As the world steps up its efforts to reduce emissions of greenhouse gases, policymakers and international negotiators are looking to the scientific community to provide answers to some important technical questions. What technologies exist or need to be developed to reduce carbon emissions? How much can these technologies reduce emissions? What will they cost?

To contribute some of the answers, the U.S. Department of Energy recently released a study called "Scenarios of U.S. Carbon Reductions: Potential Impacts of Energy Technologies by 2010 and Beyond."¹ Five national laboratories and dozens of researchers contributed to the study, which was led by Berkeley Lab's Mark Levine, Director of the Environmental Energy Technologies Division and Oak Ridge National Lab's Marilyn Brown.

Several Center for Building Science researchers participated in the work. Jonathan Koomey was lead author for the 2010 analysis of the Buildings chapter. Nathan Martin carried out detailed calculations underlying the 2010 scenarios. Many scientists from the Center reviewed and made comments on the longer-term buildings R&D section that was prepared by staff at Oak Ridge National Laboratory.

The first two chapters in the report describe the analysis results and relevant background for the study; other chapters discuss results for the buildings, industrial and transportation sectors, and the technologies that apply in these sectors. Two chapters examine the effect of upcoming changes in the structure of the electricity industry, and advanced electricity supply technologies, on carbon emission reduction.

The 200-page report reaches three major conclusions. The first is that "a vigorous national commitment to develop and deploy energy-efficient and low-carbon technologies has the potential to restrain the growth in U.S. energy consumption and carbon emissions such that levels in 2010 are close to those in 1997 for energy, and 1990 for carbon." That such a reduction is possible is suggested by three simulations of growth in energy consumption (see Figure 1). In the first, the efficiency case, the U.S. adopts policies and enhanced private-sector efforts to encourage energy-efficient technologies, with the result that it reduces carbon emissions by 120 million metric tonnes of carbon (MtC) by 2010.

The second case includes energy-efficient policies and a $25/tonne carbon permit price (tonne=metric ton), reducing emissions by 230 MtC/yr in 2010; and the third includes the policies and a $50/tonne carbon permit price. This last case reduces emissions by 390 MtC/yr by 2010--to the 1990 level of carbon emissions. The last two cases assume a major effort to reduce carbon emissions through federal and state programs and policies, active private sector involvement, and a focused national R&D effort. The study cautions that the third case--emissions reductions of 390 MtC/yr, sufficient to approximately meet 1990 levels in 2010--would take dramatic changes in U.S. commitments to energy efficiency and low-carbon technology. Its feasibility is not demonstrated.

The study's second conclusion is that, if feasible ways are found to implement the carbon reductions described here, all the cases (with reductions varying between 120 and 390 MtC) can produce energy savings that are roughly equal to or exceed costs. For the most part, the technologies exist in the marketplace and perform well technically and economically, and there are substantial increases in the economic viability of carbon reductions in electricity generation at the $50/tonne carbon charge. The challenge will be to find satisfactory ways to have the technologies accepted in the market. This is particularly the case for end-use energy efficiency technologies.

Finally, the report asserts that a new generation of energy-efficient and low-carbon technologies can continue the aggressive pace of carbon reductions after the U.S. has realized the potential of existing technologies. "Maintaining low carbon emissions beyond 2010 will require the development of new technologies," says Levine. "We describe many examples of needed R&D to illustrate the technological opportunities. And the R&D has to start soon, because the time from lab to market is often long." A variety of advanced technologies in the report could become cost-competitive in the 2010 to 2020 time frame, if an enhanced and expanded R&D program--along the lines recommended by the recent report on energy R&D by the President's Council of Advisors on Science and Technology (PCAST)--is begun soon.

The technologies that provide these carbon reductions through 2010 include efficient end-use technologies for residential and commercial buildings; industrial processes and transportation; and less-emitting supply-side technologies such as fuel cells; biomass, wind and other forms of renewable energy. Substantial near-term carbon reductions come from the retirement of coal-powered plants or their conversion to natural gas, and from efficient grid dispatch of electricity. In addition to assessing the carbon reduction effects of efficient technologies that are available now, the report discusses the potential of more advanced technologies in the post-2020 era.

Levine argues that the R&D for these new technologies requires "a strong, steady build up of capabilities--with serious efforts to maintain growth over a long period of time. While there are important differences in the opportunities for R&D success in end-use sectors and low-carbon supply technologies, I believe that overall growth in R&D efforts of 15 to 20 percent per year for the next five years, leading to a doubling in the R&D budget, makes a lot of sense. The PCAST report says much the same thing. Some programs need higher growth. Examples are: longer term R&D for energy efficiency, and for alternative fuels for vehicles (beyond the timeframe of the Partnership for a New Generation of Vehicles); low-emission diesels; lighting; information technologies applied to buildings to monitor and control buildings' operations; biomass as an energy source; and advanced control systems for a variety of industrial processes."

"We can play many roles in this work," he adds. "There are major projects here in the buildings field that need more extensive R&D--new lamp technologies [Fall 1996, p.6; Spring 1997, p.4], including a critical need to find a relatively low-cost replacement for incandescents; electrochromic glazings for windows; techniques to reduce heat islands in urban areas [Spring 1994, p.6]; and hardware and software to monitor and control commercial buildings [Summer 1994, p.6; Summer 1995, p.1]. Also, there are areas that need demonstration support in addition to research in order to move into the market sooner--for example, the duct sealant technology [Winter 1995, p.8]. And it is extremely important that we obtain information about and begin to find ways to reduce the explosive growth of a wide variety of miscellaneous energy uses in buildings, including "leaking electricity" (demand by devices that are not in active operation) that Alan Meier has made widely known." [See page 4.]

Previewing work at EETD that is in early stages of development, Levine says: "we are aggressively exploring technology development for industry and transportation, as well as new efforts for buildings. For example, we are looking into taking advantage of extensive work in electrochemistry to apply to batteries and fuel cells. And we are just beginning new efforts assessing industrial energy efficiency technology."

With the five-laboratory carbon-reduction study and the greenhouse gas treaty negotiations in the public eye, the coming year should see further evolution in plans for R&D on carbon emissions reduction technology.

--Allan Chen

Mark Levine
Environmental Energy Technologies Division
(510) 486-5001; (510) 486-5454 fax

The report "Scenarios of U.S. Carbon Reductions: Potential Impacts of Energy Technologies by 2010 and Beyond" is available on the Web.

This work was supported by the Department of Energy's Office of Energy Efficiency and Renewable Energy.

¹ Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory, National Renewable Energy Laboratory, Argonne National Laboratory, Pacific Northwest National Laboratory.