This chapter also is available as a PDF file.

Hardcopy versions of the full report can be ordered from the Global Change Research Information Office online catalog.

See also:

Press release (dated 20 September 2006)

Chapter 4: Reducing Emissions from Energy End Use and Infrastructure

Historically, global energy productivity-loosely measured in terms of economic output per unit of energy input-has shown steady increases, averaging gains of about 0.9 percent per year over the period 1971 to 2002 (IEA 2004). Use of more energy-efficient processes and replacement of older, less-efficient capital stock are important contributors to these gains. Another factor in increasing individual country measures of energy productivity, especially in industrialized countries, has been a shift over the past several decades in the composition of economic output toward less energy-intensive goods and services.

Energy End-Use
Potential Contributions to Emissions Reduction Potential contributions of Energy End-Use reduction to cumulative GHG emissions reductions to 2100, across a range of uncertainties, for three advanced technology scenarios. See Chapter 3 for details.

In published scenarios of CO₂ emissions over the 21st century, increasing demand for energy services, driven by population and economic growth, results in growth of CO₂ emissions. By contrast, almost all scenarios that explore various future paths toward significant emissions reductions show that energy end-use reduction [2] plays a key role in achieving those reductions. In one set of scenarios, as shown in Figure 3-19 and highlighted above, energy end-use reductions led to a cumulative decrease (over 100 years) of between 7 and 22 thousand exajoules (EJ) in global energy use, and between 110 and 270 gigatons of reduced or avoided global emissions of carbon (GtC), compared to a reference case used in the study (see Chapter 3). Although bracketed by uncertainties, this figure suggests both the potential role for advanced technology and a long-term goal for contributions from this sector of the global economy.

In the United States, the largest end-use sources of CO₂ emissions (Table 4-1) are the following:

• Electricity and fuel use in buildings;
• Transportation fuels;
• Electricity and fuel use in industry; and
• A few industrial processes not related to combustion.

This chapter explores energy end-use and carbon emission-reduction strategies and opportunities within each of these end-use categories. Sections 4.1 through 4.3 address transportation, buildings, and industry, respectively. Section 4.4 deals with technology strategies for the electric grid and infrastructure that can enable and facilitate CO₂ emissions reductions in all sectors. Each section provides information on its respective sector, explores the potential role for advanced technology in reducing emissions, outlines a strategy for technology development, describes the current portfolio, and identifies potential directions for future research. This chapter focuses primarily on reducing and avoiding CO₂ emissions. Many industrial processes and energy end uses produce significant quantities of other non-CO₂ GHGs. These other GHGs are addressed in Chapter 7, "Reducing Emissions of Other Greenhouse Gases." The descriptions of the technologies and deployment programs in this section include active Internet links to an updated version of the CCTP report Technology Options in the Near and Long Term (CCTP 2005). [3]

CO₂ Emissions in the United States by End-Use Sector, 2003 (GtC)

Table 4-1 CO₂ Emissions in the United States by End-Use Sector, 2003 (GtC)

4.1 Transportation

Transportation Sector Energy Use by Mode and Type

Figure 4-1 Projected Energy Consumption in U.S. Highway Vehicles. Source: EIA 2004

Potential Role of Technology

CO₂ Emissions in the United States from Transportation, by Mode, in 2003 (GtC)

Table 4-2 CO₂ Emissions in the United States from Transportation, by Mode, in 2003 (GtC)

The focus of CCTP is on technology developments that may reduce or capture GHG emissions, but it should be noted that, in the transportation sector particularly, there are non-technological options for policymakers to consider as well. They will not be discussed in the rest of this chapter, but they are worth mentioning here. For instance, local investments in bicycle lanes and paths and in pedestrian-friendly development planning can help reduce total vehicle-miles traveled. Urban and suburban planning that is well integrated with public transportation can similarly reduce fuel use per person-mile of travel. In addition, new communications technologies may alter the concepts about individual mobility. Work locations may be centered near or in residential locations, and work processes and products may be more commonly communicated or delivered via digital media. With global trends toward increasing urbanization in both population concentrations and opportunities for employment, people may rely in the future on improved modes of local, light-rail or intra-city passenger transport, coupled with other advances in electrified intercity transport that would curb the growth of fuel use and emissions from transportation.

Technology Strategy

Realizing these opportunities requires a research portfolio that embraces a combination of advanced vehicle, fuel, and transportation system technologies. Within constraints of available resources, a balanced portfolio needs to address major sources of CO₂ emissions in this sector, including passenger cars, light trucks, and other trucks; key modes of transport, including highway, aviation, and urban transit; system-wide planning and enhancements; and both near- and long-term opportunities.

In the near term, CO₂ emissions and transportation energy use can be reduced through improved vehicle efficiency, clean diesel engines, hybrid propulsion, and the use of hydrogenated low-sulfur gasoline. Other fuels, such as ethanol, natural gas, electricity with storage, and biodiesel, can also provide attractive means for reducing emissions of CO₂. These efficiency gains and fuel alternatives also provide other benefits, such as improving urban and regional air quality and enhancing energy security.

In aviation, emissions could be lowered through new technologies to improve air traffic management. An example is Reduced Vertical Separation Minimums (RVSM). RVSM has been used for transatlantic flights since 1997, and it became standard in U.S. airspace in January 2005. Full implementation of RVSM may reduce fuel use by approximately 500 million gallons each year.

In the long term, hydrogen may prove to be a low- or no-net-carbon energy carrier, if it can be cost-effectively produced with few or no GHG emissions, such as with renewable or nuclear energy, or with fossil fuels in conjunction with carbon capture and storage. Hydrogen and biofuels as substitutes for petroleum-based fuels in the transportation and other sectors also offer significant national security benefits. Hydrogen and alternative fuels are discussed in more depth in Chapter 5, "Reducing Emissions from Energy Supply." Hydrogen can be used in internal combustion engines, but its use in highly efficient fuel-cell-powered vehicles is considered a very important future option (Figure 4-2). In aviation, new engines and aircraft will feature enhanced engine cycles, more efficient aircraft aerodynamics, and reduced weight- thereby improving fuel efficiency. Research sponsored by the Federal Government through NASA, in collaboration with the Next Generation Air Transportation System (NGATS) plan, could enable these enhancements. NGATS is a multi-agency-integrated effort to ensure that the future air transportation system meets air transportation security, mobility, and capacity needs, while reducing environmental impacts.

Current Portfolio

• Research on light vehicles, organized primarily in support of the FreedomCAR and Fuel Partnership, focuses on materials; power electronics; hybrid vehicles operating on gasoline, diesel, or alternative fuels; high-efficiency, low-emission advanced combustion engines, enabled by improved fuels; and high-volume, cost-effective production of lightweight materials. Beginning in Fiscal Year 2007, the Department of Energy is increasing the funding for advanced batteries, power electronics, and systems analyses specifically needed to accelerate the introduction of "plug-in" hybrid vehicles, which provide their owners with the option of operating as a normal hybrid vehicle or in all-electric mode, consuming no petroleum at all. With appropriate power-aggregation infrastructure, these vehicles can potentially also act as grid-attached storage when they are parked, contributing to electric grid stability.

  The vehicle technologies research programs have a number of specific goals: (a) electric propulsion systems with a 15-year life capable of delivering at least 55 kW for 18 seconds and 30 kW continuous at a system cost of $12/kW peak; (b) internal combustion engine powertrain systems costing $30/kW, having peak brake engine efficiency of 45 percent, and that meet or exceed emissions standards; (c) electric drivetrain energy storage with a 15-year life at 300 Wh with discharge power of 25kW for 18 seconds and $20/kW; (d) material and manufacturing technologies for high-volume production vehicles, which enable/support the simultaneous attainment of 50 percent reduction in the weight of vehicle structure and subsystems, affordability, and increased used of recyclable/renewable materials; and (e) internal combustion engine powertrain systems, operating on hydrogen with a cost target of $45/kW by 2010 and $30/kW in 2015, having a peak brake engine efficiency of 45 percent, and that meet or exceed emissions standards. [4]

• Research areas for heavy vehicles, organized primarily under the 21st Century Truck Partnership, include lightweight materials, aerodynamic drag, tire rolling resistance, electrification of ancillary equipment, advanced high-efficiency combustion propulsion systems (including energy-efficient emissions reduction), fuel options (both petroleum- and non-petroleum-based), hybrid technologies for urban driving applications, and onboard power units for auxiliary power needs. The research objectives are to: (1) reduce energy consumption in long-haul operations, (2) increase efficiency and reduce emissions during stop-and-go operations, and (3) develop more efficient and less-polluting energy sources to meet truck stationary power requirements (i.e., anti-idling). By 2010, the goals include a laboratory demonstration of an emissions-compliant engine system that is commercially viable for Class 7-8 highway trucks, and an engine that improves the system efficiency to 53 percent by 2010 and to 55 percent by 2013, from the 2002 baseline of 40 percent. By 2012, the goals include advanced technology concepts that reduce the aerodynamic drag of a Class 8 tractor-trailer combination by 20 percent. [5]

• Fuels research encompasses the development of new fuel blend formulations that will enable more efficient and cleaner combustion and the development of renewable and non-petroleum-based fuels that could displace 5 percent of petroleum used by commercial vehicles. [6]

• Research on intelligent transportation systems infrastructure includes sensors, information technology, and communications to improve efficiency and ease congestion. Intelligent transportation systems (ITS) goals include improved analysis capabilities that properly assess the impact of ITS strategies and strategies that will improve travel efficiency resulting in lower delays, thereby reducing emissions. [7]

• Research on aviation fuel efficiency includes engine and airframe design improvements. Aviation fuel efficiency goals include improved aviation fuel efficiency per revenue plane-mile by 1 percent per year through 2008, and new technologies with the potential to reduce CO₂ emissions from future aircraft by 25 percent within 10 years and by 50 percent within 25 years. [8]

• Best Workplaces for Commuters program is a voluntary employer-adopted program that increases commuter flexibility by expanding transportation mode options, using flexible scheduling, and increasing work location choices.

Figure 4-2 In the longer term, hydrogen fuel cell vehicles may provide for a transportation future that has much lower CO₂ emissions. Courtesy: DOE/NREL, Credit: SunLine Transit Agency

• The Clean Cities program supports efforts to deploy alternative fuel vehicles (AFVs) and develop the necessary supporting infrastructure. Clean Cities works through a network of more than 80 volunteer, community-based coalitions, which develop public/private partnerships to promote the use of alternative fuels and vehicles, expand the use of fuel blends, encourage the use of fuel economy practices, increase the acquisition of hybrid vehicles by fleets and consumers, and advance the use of idle reduction technologies in heavy-duty vehicles.

• Congestion Mitigation and Air Quality Improvement Program, administered by the U.S. Department of Transportation, in consultation with the EPA, provides states with funds to reduce congestion and to improve air quality through transportation control measures and other strategies.

• Mobile Air Conditioning Climate Protection Partnership strives to reduce GHG emissions from vehicle air conditioning systems through voluntary approaches. The program promotes cost-effective designs and improved service procedures that minimize emissions from mobile air conditioning systems.

• SmartWay Transport Partnership program is designed to reduce emissions from the freight sector through the implementation of innovative technology and advanced management practices. To date, 133 companies have joined the Partnership and have committed to reduce the CO₂ emissions associated with their respective freight operations. Additionally, there are now over 50 diesel truck and locomotive engine idling reduction projects around the country.

Future Research Directions

The current portfolio supports the main components of the technology development strategy and addresses the highest priority current investment opportunities in this technology area. For the future, CCTP seeks to consider a full array of promising technology options. From diverse sources, suggestions for future research have come to CCTP's attention. Some of these, and others, are currently being explored and under consideration for the future R&D portfolio. These include:

• Freight Transport. Strategies and technologies to address congestion in urban areas and freight gateways by increasing freight transfer and movement efficiency among ships, trucks and rail in anticipation of large growth in freight volumes.
  
  
• Advanced Urban Concepts. Studies of advanced urban-engineering concepts for cities to evaluate alternatives to urban sprawl. Such engineering analysis would consider the co-location of activities with complementary needs for energy, water, and other resources; and would enable evaluation of alternative configurations that could significantly reduce vehicle-miles traveled and GHG emissions.
  
  
• Integrated Urban Planning. Concept and engineering studies for large-scale institutional and infrastructure changes required to manage CO₂, electricity, and hydrogen systems reliably and securely. Analysis of the infrastructure requirements for plug-in hybrid electric vehicles is needed. By being plugged into the power grid at night, when electricity is cheapest and most available, and by operating solely on battery power for the first 10-60 miles, this technology could significantly reduce oil consumption.
  
  
• Large-Scale Hydrogen Storage. Technologies for large-scale hydrogen storage and transportation and low-cost, lightweight electricity storage including advanced batteries and ultracapacitors.

In addition, supporting or crosscutting areas for future research include the following:

• Advanced Thermoelectric Concepts. Advanced thermoelectric concepts to convert temperature differentials into electricity, made more affordable through nanoscale manufacturing.
  
  
• Battery and Fuel Cell Systems. Basic electrochemistry to produce safe, reliable battery and fuel cell systems with acceptable energy and power density, cycle life, and performance under temperature extremes.
  
  
• New Combustion Regimes. Advanced combustion research on new combustion regimes in conventional vehicle propulsion technologies, using conventional fuels as well as alternatives such as cellulosic ethanol and biodiesel where near-zero regulated emissions and lowered carbon emissions can be achieved.

Residential and Commercial CO₂ Emissions in the United States, by Source, in 2003 (GtC)

Table 4-3 Residential and Commercial CO₂ Emissions in the United States, by Source, in 2003 (GtC)

Buildings

The built environment-consisting of residential, commercial, and institutional buildings-accounts for about one-third of primary global energy demand (IPCC 2000) and represents a major source of energy-related GHG emissions, mainly CO₂. Growth in global energy demand in buildings has averaged 3.5 percent per year since 1970 (IPCC 2001).

Over the long term, buildings are expected to continue to be a significant component of increasing global energy demand and a large source of CO₂ emissions. Energy demand in this sector will be driven by growth in population, by the economic expansion that is expected to increase the demand for building services (especially electric appliances, electronic equipment, and the amount of conditioned space per person), and by the continuing trends toward world urbanization. As urbanization occurs, energy consumption increases, because urban buildings usually have electricity access and have a higher level of energy consumption per unit area than buildings in more primitive rural areas. According to a recent projection by the United Nations, the percentage of the world's population living in urban areas will increase from 49 percent in 2005 to 61 percent by 2030 (UN 2005).

In the United States, energy consumption in residential buildings has been increasing proportionately with increases in population, while energy consumption in commercial buildings has tended to follow the level of economic activity, or real Gross Domestic Product (GDP). [9] This trend masks significant increases in efficiency in some building components that are being offset by new or increased energy uses in others. In the United States in 2003, CO₂ emissions from this sector, including those from both fuel combustion and use of electricity derived from CO₂-emitting sources, accounted for nearly 37 percent of total CO₂ emissions (Table 4-1). These emissions have been increasing at 1.9 percent per year since 1990 (EIA 2005). Table 4-3 shows a breakdown of emissions from the buildings sector, by fuel type, in the United States.

Potential Role of Technology

Many opportunities exist for advanced technologies to make significant reductions to energy-related CO₂ emissions in the buildings sector. In the near term, widespread adoption of advanced commercially available technologies, such as ENERGY STAR® compliant equipment, can improve efficiency of energy-using equipment in the primary functional areas of energy use. In residential buildings, these functional areas include space heating, appliances, lighting, water heating, and air conditioning. In commercial buildings, functional areas are lighting, space heating, cooling and ventilation, water heating, office equipment, and refrigeration. Through concerted research, major technical advances have occurred during the past 20 years, with many application areas seeing efficiency gains of 15 percent to 75 percent. Figure 4-3 gives an example of technological improvements that have occurred in refrigerators as an illustration of the kind of gains that have been achieved. Over the longer term, more advances can be expected in these areas, and significant opportunities also lie ahead in the areas of new buildings design, retrofits of existing buildings, and the integration of whole building systems and multi-building complexes through use of sensors, software, and automated maintenance and controls.

By 2025-with advances in building envelopes, equipment, and systems integration-it may be possible to achieve up to a 70 percent reduction in a building's energy use, compared to the average energy use in an equivalent building today (DOE 2005). If augmented by on-site energy technologies (such as photovoltaics or distributed sources of combined heat and power), buildings could become net-zero GHG emitters and net energy producers.

Technology Strategy

While the built environment is a complex mix of heterogeneous building types (commercial, service, detached dwelling, apartment buildings) and functional uses, all have common features, each of which may benefit from technological research, both as individual components and as integrated systems. Within constraints of available resources, a balanced portfolio needs to address three important aspects of buildings that affect their CO₂ emissions: (1) integrated building design, construction, and operation, including the optimal integration of components; (2) advanced building envelope components, including windows and walls; and (3) advanced, building equipment, appliances, and lights. The portfolio should look at both near- and long-term opportunities.

In the near term, building energy use and CO₂ emissions could be lowered in several ways. Especially in new construction, design strategies that incorporate energy- and material-saving strategies from the very start of the building process can result in significant avoided carbon. Intelligent building systems (such as load balancing and automated sensors and controls) can also be included to help ensure the comfort, health, and safety of residents, as well as aid in the reduction of CO₂. In the building envelope, application of advanced materials such as high R-value insulation, foams, vacuum panels, and spectrally selective windows can reduce space conditioning loads significantly. Choosing highly recyclable materials such as aluminum can reduce the end-of-life impact of building design and contribute to sustainable building practices. Technologies to improve the efficiency of lighting, appliances, heating, cooling, and ventilation are other options.

Figure 4-3 Refrigerator Energy Efficiency (Source: Brown 2003)

In the long term, more advanced research on the building envelope-including dynamic switchable window glazings and dynamic walls, panelized housing construction, fa�ade and roof integration of photovoltaics, and new storage technologies-can drive CO₂ emissions even lower. Distributed power systems, advanced refrigeration and cooling technologies, integrated heat pumps that serve space conditioning and water heating, and solid-state lighting technology are among some of the more promising options for equipment. Among the alternatives, building integration should focus on including sensors and controls, community-scale integration tools, and urban engineering.

Current Portfolio

The current Federal portfolio focuses on four major thrusts. In combination, these activities aim to achieve net-zero-energy residential buildings by 2020 and commercial buildings by 2025.

• Research on the building envelope (the interface between the interior of a building and the outdoor environment) focuses on systems that determine or provide control over the flow of heat, air, moisture, and light in and out of a building; and on materials that can affect energy use, including insulation, foams, vacuum panels, optical control coatings for windows and roofs, thermal storage, and related controls (such as electrochromic glazings). Research program goals in the building envelope area include the following: (1) by 2008, demonstrate dynamic solar control windows (electrochromics) in commercial buildings, and by 2010 demonstrate market-viable windows with R6 insulation performance for homes; (2) by 2025, develop marketable and advanced energy systems capable of achieving "net-zero" energy use in new residential and commercial buildings; (3) for the long term, and consistent with achieving net zero energy performance, achieve a 30 percent decrease in the average envelope thermal load of existing residential buildings and a 66 percent decrease in the average thermal load of new buildings. [10]
  
  
• Research on building equipment focuses on means to significantly improve efficiency of heating, cooling, ventilating, thermal distribution, lighting (Figure 4-4), home appliances, and on-site energy and power devices. This area also includes a number of crosscutting elements, including advanced refrigerants and cycles, solid-state lighting, smart sensors and controls, small power supplies, microturbines, heat recovery, and other areas.
  
  Specific goals include: (1) for distributed electricity generation technologies (including microturbines), by 2008, enable a portfolio of equipment that shows an average 25 percent increase in efficiency; (2) for solid-state lighting in general illumination applications, by 2008, develop equipment with luminous efficacy of 79 lumens per watt (LPW); and, for laboratory devices by 2025, a luminous efficacy of 200 LPW. The long-term goals are: (1) by 2025, develop and demonstrate marketable and advanced energy systems that can achieve "net-zero" energy use in new residential and commercial buildings through a 70 percent reduction in building energy use; and (2) by 2030, enable the integration of all aspects of the building envelope, equipment, and appliances with on-site micro-cogeneration and zero-emission technologies. [11]

Figure 4-4 Many opportunities exist for advanced technologies, such as the sub-compact fluorescent coil light bulb, to make significant reductions of CO₂ emissions in the building sector. Courtesy: DOE/NREL

• Research on residential systems integration, focuses on progressively higher levels of energy performance over time, and follows a three-phase approach. Phase 1, systems evaluation, involves the design, construction and testing of subsystems for whole house designs (by climate zone) in research houses to evaluate how components perform. In Phase 2, prototype houses (Figure 4-5), the successful Phase 1 subsystems are designed and constructed by production builders to evaluate the ability to implement the systems on a production basis. Phase 3, community evaluations, provides technical support to builder partners to advance from the production prototypes to evaluation of production houses in a subdivision.
  
  
• Research on commercial buildings integration includes development of advanced design "packages" of system-integrated design strategies and operational methodologies for high-performance buildings, which can be used by architects and others to design, build, and operate commercial buildings in an integrated manner. This approach is targeted at new construction, because the opportunities for aggressive performance are much greater than in existing buildings. In addition, R&D includes load balancing and automated sensors and controls, sometimes referred to as intelligent building systems. Such systems continuously monitor building performance, detect anomalies or degradations, optimize operations across all building systems, guide maintenance, and document and report results. They can also be extended to coordinate on-site energy generation and internal loads, with external power (grid) demands and circumstances, allowing responsiveness to time-variant cost savings, system efficiencies, and grid contingencies. They also ensure occupant comfort, health, and safety, met at the lowest possible cost.
  
  
• Whole building integration goals include fully and seamlessly integrated building design tools, such as EnergyPlus, that support all aspects of design and provide rapid analysis of different pathways to improved energy performance. Also included are the development of automatic operation of buildings systems that require little operator attention; and highly efficient combined cooling, heating, and power systems that use waste heat from small-scale, on-site electricity generation to provide heating and cooling for the buildings, as well as export excess electricity to the grid. [12]
  
  
• The ENERGY STAR® is a joint program of EPA and DOE that enables businesses, organizations, and consumers to realize the cost savings and environmental benefits of energy efficiency investments. Introduced in 1992, the ENERGY STAR® program focuses on four areas of energy efficiency that include products, home improvement, new homes, and business improvement. By providing resources, working with local partners, and labeling ENERGY STAR® qualified-products, the program makes it easy for consumers and businesses to make smart energy-efficient choices that can save about a third on energy bills with similar savings of GHG emissions, without sacrificing features, style or comfort.

Figure 4-5 Design strategies that incorporate energy- and material-saving strategies can result in significant reduction of CO₂ emissions. Courtesy: DOE

• Federal Energy Management Program aims to reduce energy use in Federal buildings, facilities, and operations by advancing energy efficiency and water conservation, promoting the use of renewable energy, and managing utility choices of Federal agencies. The program accomplishes its mission by leveraging both Federal and private resources to provide Federal agencies the technical and financial assistance they need to achieve their goals.
  
• Rebuild America works with a network of hundreds of community-based partnerships across the nation that are saving energy, improving building performance, easing air pollution through reduced energy demand, and enhancing the quality of life through energy efficiency and renewable energy technologies.
  
  
• Residential Building Integration: Building America is intended to design, build, and evaluate energy-efficient homes that use from 30 to 40 percent less total energy than comparable traditional homes with little or no increase in construction costs; and to encourage industry to adopt these practices for new home construction. In addition, ongoing research focuses on integrating onsite power systems, including renewable energy technologies. Through the Building America program, DOE and its more than 470 industry partners are conducting research to develop advanced building energy systems to make homes and communities much more energy efficient.
  
  
• State Energy Program extends grants from DOE to states for a variety of energy-efficiency and renewable-energy activities. Most states have a state energy office designated to help reduce energy waste and increase the use of renewables in the state.
  
  
• Weatherization Assistance Program provides cost-effective energy-efficiency improvements to low-income households through the weatherization of homes. Priority is given to the elderly, persons with disabilities, families with children, and households that spend a disproportionate amount of their income on energy bills (utility bills make up 15 to 20 percent of household expenses for low income families, compared to five percent or less for all other Americans).

Future Research Directions

The current portfolio supports many of the components of the technology development strategy and addresses the highest priority current investment opportunities in this technology area. For the future, CCTP seeks to consider a full array of promising technology options. From diverse sources, suggestions for future research have come to CCTP's attention. Some of these, and others, are currently being explored and under consideration for the future R&D portfolio. These include:

• Building Envelope. Improved panelized housing construction; methods for integrating photovoltaic systems in bui lding components such as roofs, walls, skylights, and windows, and with building loads and utilities; and exploration of fundamental properties and behaviors of novel materials to maximize moisture resistance and the storage and release of energy. Through nanotechnology advances, research will develop smart roofs and walls that reflect infrared solar radiation in summer and absorb it in winter, with substantial energy savings.
  
  
• Building Equipment. Advances in on-site power production (including fuel cells, microturbines, and reciprocating engines); ultra-efficient Heating, Ventilating, and Air-Conditioning-Residential (HVACR) (including magnetic or solid state cooling systems, advanced desiccants and absorption chilling systems, integrated heat pump systems for space conditioning and water heating, and highly efficient geothermal heat pumps); improved hot water circulation systems; and solid state lighting technology and improved lighting distribution systems. Low-power ubiquitous sensors with wireless communications can optimize building operations through anticipatory and selective heating, cooling, and lighting that manage loads in response to occupant requirements and real-time energy prices.
  
  
• Whole Building Integration. Further development and widespread implementation of building design tools for application in new and retrofit construction; tools and technologies for systems integration in buildings, with a particular focus on sensors and controls for supply and end-use system integration; development of pre-engineered, optimized net-zero energy buildings; community-scale design and system integration tools; and urban engineering to reduce transport energy use and congestion.

4.3 Industry

In the United States in 2003, industry accounted for about one-third of total U.S. CO₂ emissions (Table 4-1). These are attributed to combustion of fuels (51 percent), use of electricity derived from CO₂-emitting sources (41 percent), and industrial processes, including non-combustion processes, that emit CO₂ (8 percent) (Table 4-4). [13]

Potential Role of Technology

In the long term, fundamental changes in energy infrastructure could effect significant CO₂ emissions reductions. Revolutionary changes may include novel heat and power sources and systems, including renewable energy resources, hydrogen, and fuel cells. Innovative concepts for new products and high-efficiency processes may be introduced that can take full advantage of recent and promising developments in nanotechnology, micro-manufacturing, sustainable biomass production, biofeedstocks, and bioprocessing. As global industry's existing, capital-intensive equipment stock nears the end of its useful service life and as industry expands in rapidly emerging economies in Asia and the Americas, this sector will have an opportunity to adopt novel technologies that could revolutionize basic manufacturing. Advanced technologies will likely involve a mix of pathways, such as on-site energy generation, conversion, and utilization; process efficiency improvements; innovative or enabling concepts, such as advanced sensors and controls, materials, and catalysts; and recovery and reuse of materials and byproducts (Figure 4-6). In the United States, the development and adoption of advanced industrial technologies can not only provide GHG benefits, but also help to maintain U.S. competitiveness.

CO₂ Emissions in the United States from Industrial Sources in 2003 (GtC) (Excludes Indirect Emissions from Industrial Use of Centrally-Generated Electric Power)

Table 4-4 CO₂ Emissions in the United States from Industrial Sources in 2003 (GtC) (Excludes Indirect Emissions from Industrial Use of Centrally-Generated Electric Power)

Technology Strategy

In the near term, industrial energy use and CO₂ emissions could be lowered through improvements in the industrial use of electricity and fuels to produce process heat and steam, including steam boilers, direct-fired process heaters, and motor-driven systems, such as pumping and compressed air systems. Opportunities for reducing emissions in these areas lie with the adoption of best energy-management practices; adoption of more modern and efficient power and steam generating systems; integrated approaches that combine cooling, heating, and power needs; and capture and use of waste heat. Other areas of opportunity include improvements in specific energy-intensive industrial processes, including hybrid distillation systems; process intensification by combining or removing steps, or designing new processes altogether while producing the same or a better product; the recovery and utilization of waste and feedstocks, which can reduce energy and material requirements; and crosscutting opportunities, such as improved operational capabilities and performance.

In the long term, highly efficient coal gasifiers coupled with CO₂ sequestration technology could provide an alternative to natural gas, and even enable the export of electricity and hydrogen to the utility grid and supply pipelines. Bioproducts could replace fossil feedstocks for manufacturing fuels, chemicals, and materials; while biorefineries could utilize fuels from nonconventional feedstocks to jointly produce materials and value-added chemicals. For non-combustion sources of CO₂, gas capture, separation and sequestration could be applied, or alternative processes or materials could be developed as substitutes. Further, integrated modeling of fundamental physical and chemical properties, along with advanced methods to simulate processes, will stem from advances in computational technology.

Figure 4-6 Four Possible Pathways to Increased Industrial Efficiency (Source: DOE 1997)

Current Portfolio

• Research on energy conversion and utilization focuses on a diverse range of advanced and integrated systems. These include advanced combustion technologies, gasification technologies, high-efficiency burners and boilers, thermoelectric technologies (Figure 4-7) to produce electricity using industrial waste heat streams, co-firing with low-GHG fuels, advanced waste heat recovery heat exchangers, and heat-integrated furnace designs. Integrated approaches include combined-cycle power generation, and cogeneration of power and process heat or cooling.
  
  The overall research program goal in this area is to contribute to a 20 percent reduction in the energy intensity (energy per unit of industrial output, as compared to 2002) of energy-intensive industries by 2020. Several specific goals include: (1) by 2006, demonstrate a greater than 94 percent efficient packaged boiler, and, by 2010, have commercially available packaged boilers with thermal efficiencies of 10-12 percent higher than conventional technology; (2) by 2008, demonstrate high-efficiency pulping technology in the pulp and paper industry that redirects green liquor to pretreat pulp and reduce lime kiln load and digester energy intensity; and (3) by 2011, demonstrate isothermal melting technology, which could improve efficiency significantly in the aluminum, steel, glass, and metal-casting industries. [14]
  
  
• Research on specific, energy-intensive and high-CO₂-emitting industrial processes focuses on identifying (compared to theoretical minimum energy requirements) and removing process inefficiencies, lowering overall energy requirements for heat and power, and reducing CO₂ emissions. One process under development is a means to produce high-quality iron without the use of metallurgical coke, which-under current methods of steelmaking-is a significant source of CO₂ emissions. Other areas of research focus on processes that may also improve product yield, including oxidation catalysis, advanced processes, and alternative processes that take a completely different route to the same end product, such as use of noncarbon inert anodes in aluminium production.
  
  Industrial process efficiency goals are focused on industry partnerships. The overall research program goal in this area is to realize, before 2020, a 20 percent improvement in energy intensity by the energy-intensive industries through the development and implementation of new and improved processes, materials, and manufacturing practices. [15]
  
  
• Research on enabling technologies includes an array of advanced materials that resist corrosion, degradation, and deformation at high temperatures and pressures; inferential sensors, controls, and automation, with real-time nondestructive sensing and monitoring; and new computational techniques for modeling and simulating chemical pathways and advanced processes.

Figure 4-7 Industrial energy use and CO₂ emissions could be lowered through the use of high-efficiency combustion processes, such as oxy-fuel firing for glass manufacturing. Courtesy of DOE/EERE

Research program goals for this area target new enabling technologies that meet a range of cost goals depending on the technologies and on the applications where they are to be used. Specific goals include: (1) by 2010, demonstrate production and application of nano-structured diamond coatings and composites and other ultra-hard materials for use in wear-intensive industrial applications, and develop materials for use in a wide array of severe industrial environments (corrosive, high temperature, and pressure); (2) by 2012, demonstrate the generation of efficient power from high-temperature waste heat using systems with thermoelectric materials; and (3) by 2017, develop and demonstrate integration of sensing technologies with information processing to control plant production. [16]

• Research on resource recovery and utilization focuses on separating, capturing, and reprocessing materials for feedstocks. Recovery technologies include materials designed for recyclability, advanced separations, new and improved process chemistries, and sensors and controls. Reuse technologies include recycling, closed-loop process and plant designs, catalysts for conversion to suitable feedstocks, and post-consumer processing.
  
  Research program goals in this area target a range of improved recycling/recovery efficiencies. For example, in the chemicals industry the goal is to improve recyclability of materials by as much as 30 percent. Additional goals target new and improved processes to use wastes or byproducts; improve separations to capture and recycle materials, byproducts, solvents, and process water; and identify new markets for recovered materials, including ash and other residuals such as scrubber sludges. [17]
  
  
• Climate Leaders is an EPA partnership encouraging individual companies to develop long-term, comprehensive climate change strategies. Under this program, partners set corporate-wide GHG reduction goals and inventory their emissions to measure progress. The partnership now includes about 70 partners, 38 of whom have already set GHG emissions reduction goals. The US GHG emissions of these partners are equal to more than 7 percent of the U.S. total.
  
  
• Climate VISION assists industry efforts to accelerate the transition to practices, improved processes, and energy technologies that are cost-effective, cleaner, more efficient, and more capable of reducing, capturing, or sequestering GHGs. Already, business associations representing 14 industry sectors and the Business Roundtable have become program partners with the Federal Government and have issued letters of intent to meet specific targets for reducing GHG emissions intensity. These partners represent a broad range of industry sectors: oil and gas production, transportation, and refining; electricity generation; coal and mineral production and mining; manufacturing; railroads; and forestry products. Partnering sectors account for about 90 percent of industrial emissions and 40 to 45 percent of total U.S. emissions.
  
  
• Industries of the Future works in partnership with the nation's most energy-intensive industries, enhancing their long-term competitiveness and accelerating research, development, and deployment of technologies that increase energy and resource efficiency. This program has contributed to the development of hundreds of commercialized industrial technologies, resulting in a cumulative tracked energy savings of over 3,500 trillion Btu.
  
  
• Voluntary GHG Emissions Reporting under 1605(b) provides a means for organizations and individuals that have reduced their emissions to record their accomplishments and share their ideas for action. The enhanced registry will boost measurement accuracy, reliability, and verifiability, working with and taking into account emerging domestic and international approaches. Currently about 230 U.S. companies and other organizations file GHG reports.

Future Research Directions

• Industrial Alternatives to Natural Gas. Research could be conducted to develop coal gasification systems for large industrial plants (e.g., 100 megawatts). The coal gasifiers would be highly integrated into complex manufacturing plants (e.g., chemical or glass plants). The industrial plant's feedstock, process heat, and power requirements could be accommodated from the coal gasifier, which could also export electricity, hydrogen, or other fuels to the utility grid and gas supply pipelines.
  
  
• Industrial Waste Heat Reduction. Energy conversion and utilization in industry creates large amounts of waste heat. This waste heat could be minimized through beneficial electrification (including infrared drying and induction heating); novel materials that do not require drying or curing; micro-CHP (combined heat and power) systems to convert waste heat to drive other thermal processes; and new ways of boosting low-grade temperatures to more useful high-grade heat.
  
  
• Advanced Industrial Materials. Research on advanced materials can reduce energy requirements and emissions in most industries. Characterization of materials at the nanoscale can lead to engineered materials with improved functionality, including improved properties such as strength, corrosion resistance, and power conversion (e.g., thermoelectrics).
  
  
• Cement and Related Products. Research could focus on various means to reduce or eliminate CO₂ emissions from non-combustion, high-emitting industrial processes, including the cement, lime, limestone, and soda ash industries. Worldwide infrastructure building over the 21st century can be expected to create a high demand for these mineral products, the production of which releases CO₂ as a consequence of the calcining process. In the United States in 2003, CO₂ emissions from these sources accounted for 44 percent of the non-energy-related industrial emissions and about 1 percent of total U.S. emissions. Research could be focused on carbon capture and sequestration and on the exploration of substitutes for the end product. Carbon matrixes for construction, for example, might be lighter and stronger than concrete and would provide a means for carbon sequestration.
  
  
• Advanced Applications of Biotechnology. Bioproducts soon could replace fossil feedstocks, such as oil, in current industrial processes for manufacturing fuels, chemicals, and materials. Advances in biosciences and engineering include a better understanding of genomes, proteins, and their functions, including carbon dioxide capture, fixation, and storage; the effects of pre-treatment on biomass feedstock properties; enzymes for hydrolyzing pre-treated biomass into fermentable sugars; micro-organisms used in fermentation; and new tools of discovery such as bio-informatics, high-throughput screening of biodiversity, directed enzyme development and evolution, and gene shuffling. Biorefineries of the future could produce transportation fuels, value-added chemicals, materials, and/or power from non-conventional feedstocks such as agricultural and forest residues, energy crops, and other biomass materials.
  
  
• Water and Energy System Optimization. Energy used by water infrastructure and water used in power and fuel supply systems provide numerous opportunities for improvement with GHG reduction benefits. Opportunities include better matching of water temperatures and purity to end-use requirements; revolutionizing the design of municipal water systems to reduce use, minimize conveyance, and maximize re-use; and integrating water storage and treatment with the intermittency of renewable power supplies.
  
  
• Computational Technology. Process simulation enables more effective design and operation, leading to increased efficiency and improved productivity and product quality. Integrated modeling of fundamental physical and chemical properties can enhance understanding of industrial material properties and chemical processes. For example, modeling of counterflows through structured packings within distillation columns can improve hydrodynamic efficiencies and save a significant portion of the 3 quads of energy used annually in distillation processes, about half in petroleum refineries.

Figure 4-8 Advanced industrial materials, such as those used in high-temperature superconductive wires, can reduce energy losses and improve performance in electric motors. Courtesy: DOE/NREL, Credit: Reliance Electric Co.

4.4 Electric Grid and Infrastructure

In recent years, the demand for electricity in the United States has increased at a rate such that it could eventually exceed current transmission capacity. Demand is projected to increase by 19 percent from 2003-2012 (EIA 2005); only a 6 percent increase in transmission is planned for 2002-2012 (DOE 2002). There have been few major new investments in transmission during the past 15 years. Outages experienced in parts of the country-including the August 2003 blackout in the Midwest and Northeast-highlight the need to enhance grid reliability.

Enhancements for grid reliability will likely go hand in hand with improved efficiency of electricity transmission. Energy losses in the U.S. transmission and distribution (T&D) system were 5.5 percent in 2003, accounting for 201 billion kilowatt hours of electricity generation and 133 million metric tons of CO₂ emissions (EIA 2005, Table A8; EPA 2005 Table 2-14). About 10 percent of GHG emissions resulting from transmission and distribution are SF₆ emissions from certain high-voltage transmission equipment. The remainder of GHG emissions is from increased operations needed to compensate for energy losses.

Notwithstanding these improvements, the extent to which transmission and distribution losses could be reduced is uncertain, and energy losses on the transmission system could even increase as more long-distance transmission lines are brought into service to transmit power from remote generation sources.

The current portfolio supports the main components of the technology development strategy. Within constrained Federal resources, this portfolio addresses the highest priority current investment opportuni-ties. For the future, CCTP seeks to consider a full array of promising technology options. From diverse sources, suggestions for future research have come to CCTP's attention and others are currently being explored. These include:

• High-Temperature Superconducting Cables and Equipment. The manufacture of promising HTS materials in long lengths at low cost remains a key program challenge. New, continuously scanning analytical systems are necessary to ensure uniformly high superconductor characteristics over kilometer lengths of wire. Research and development could help develop highly reliable, high-efficiency cryogenic systems to economically cool the superconducting components, including materials for cryogenic insulation and standardized high-efficiency refrigerators and motors (Figure 4-8). Scale-up of national laboratory discoveries for "coated conductors" could be another promising area for the laboratories and their industry partners.
  
  
• Materials Science for Energy Conversion. The digital economy is demanding more low-voltage DC power, which underscores the need for more efficient AC-DC conversion. In addition, on-site sources of photovoltaic (PV) and wind energy would be more efficiently utilized by supplying electricity to DC appliances, which will necessitate a new generation of smart wiring in homes and offices to allow both AC and DC power and end uses.
  
  
• Energy Storage. Energy storage that responds over timescales from milliseconds to hours and outputs that range from watts to megawatts is a critical enabling technology for enhancing customer reliability and power quality, more effective use of renewable resources, integration of distributed resources, and more reliable transmission system operation.
  
  
• Real-Time Monitoring and Control. Introduction of low-cost sensors throughout the power system is needed for real-time monitoring of system conditions. New analytical tools and software must be developed to enhance system observability and power flow control over wide areas.

Potential Role of Technology

Figure 4-9 Superconductor wires have the ability to conduct more than 150 times the electrical current of copper wire of the same dimension. Courtesy: American Superconductor.

Advanced conductors integrate new materials with existing materials and other components and subsystems to achieve better technical, environmental, and financial performance-e.g., higher current carrying capacity, more lightweight, greater durability, lower line losses, and lower installation and operations and maintenance costs. Improved sensors and controls, as part of the next-generation electricity T&D system, could significantly increase the efficiency of electricity generation and delivery, thereby reducing the GHG emissions intensity associated with the electric grid. Outfitting the system with digital sensors, information technologies, and controls could further increase system efficiency, and allow greater use of more efficient and low-GHG end-use and other distributed technologies. High-temperature superconductors may be able to be utilized in key parts of the T&D system to reduce or eliminate line losses and increase efficiency. Energy storage allows intermittent renewable resources, such as photovoltaics and wind, to be dispatchable.

Advanced storage concepts and particularly high-temperature superconducting wires and equipment represent longer-term solutions with great promise. Digital sensors, information technologies, and controls may eventually enable real-time responses to system loads. HTS electrical wires might be able to carry 150 times the amount of electricity compared to the same-size conventional copper wires (Figure 4-9). Such possibilities may create totally new ways to operate and configure the grid. Power electronics will be able to provide significant advantages in processing power from distributed energy sources using fast response and autonomous control.

Technology Strategy

Early research is likely to focus on ensuring reliability, e.g., establishing "self-healing" capabilities for the grid, including intelligent, autonomous device interactions, and advanced communication capabilities. Additional technologies would be needed for wide-area sensing and control, including sensors, secure communication and data management; and for improved grid-state estimation and simulation. Simulation linked to intelligent controllers can lead to improved protection and discrete-event control. Digitally enabled load-management technologies, wireless communications architecture and algorithms for system automation, and advanced power storage technologies will allow intermittent and distributed energy resources to be efficiently integrated.

Longer-term research is likely to focus on the development of fully operational, pre-commercial prototypes of energy-intensive power equipment that, by incorporating HTS wires, will have greater capacity with lower energy losses and half the size of conventional units. Over the long term, the T&D system would also be enhanced by integrating storage and power electronics.

Current Portfolio

• Research on high-temperature superconductivity (HTS) is focused on improving the current carrying capability of long-distance cables; its manufacturability; and cost-effective ways to use the cable in equipment such as motors, transformers, and compensators. More reliable and robust HTS transmission cables that have three to five times the capacity of conventional copper cables and higher efficiency-which is especially useful in congested urban areas-are being developed and built as pre-commercial prototypes. Through years of Federal research in partnership with companies throughout the nation, technology has developed to bond these HTS materials to various metals, providing the flexibility to fashion these ceramics into wires for use in transmission cables; bearings for flywheels; and coils for power transformers, motors, generators, and the like.
  
  Research program goals in this area include HTS wires with 100 times the capacity of conventional copper/aluminum wires. More broadly, the program aims to develop and demonstrate a diverse portfolio of electric equipment based on HTS, such that the equipment can achieve a 50 percent reduction in energy losses, compared to conventional equipment, and a 50 percent size reduction, compared to conventional equipment with the same rating. Low-cost, high-performance, second-generation coated conductors are expected to become available in 2008 in kilometer-scale lengths. Cost goals include: (1) in 1,000 meter lengths, a wire-cost goal of $50 or less per ampere of current carried by superconducting wire used in power lines cooled to liquid nitrogen temperatures; (2) by 2015, the cost performance ratio for superconducting wires improved by at least a factor of 2. [18]
  
  
• Research on transmission and distribution technologies is focused on real-time information and control technologies; and systems that increase transmission capability, allow economic and efficient electricity markets, and improve grid reliability. Examples include high-strength composite overhead conductors, grid-status measurement systems that improve reliability by giving early warning of unstable conditions over major geographic regions, and technologies and regulations that enable the customer to participate more in electric markets through a demand response. [19]

Figure 4-10 A Distributed Energy Future (Source: ORNL, Oak Ridge, Tennessee)

Research program goals in this area include, by 2010, demonstrated reliability of energy-storage systems; reduced cost of advanced conductors systems by 30 percent; and operation of a prototype smart, switchable grid in a region within the U.S. transmission grid.

• Research on distributed generation (DG) includes renewable resources (e.g., photovoltaics), natural gas engines and turbines, energy-storage devices, and price-responsive loads. These technologies can meet a variety of consumer energy needs, including continuous power, backup power, remote power, and peak shaving. They can be installed directly on the consumer's premises or located nearby in district energy systems, power parks, and mini-grids (Figure 4-10).
  
  Current research focuses on technologies that are powered by natural gas combustion and are located near the building or facility where the electricity is being used. These systems include microturbines, reciprocating engines and larger industrial gas turbines that generate from 25 kW to 10 MW of electricity that is appropriate for hotels, apartment buildings, schools, office buildings, hospitals, etc. Combined cooling, heating, and power (CHP) systems recover and use waste heat from distributed generators to efficiently cool, heat, or dehumidify buildings or make more power.
  
  Research is needed to increase the efficiency and reduce the emissions from microturbines, reciprocating engines, and industrial gas turbines to allow them to be sited anywhere, even in nonattainment areas. These technologies can meet a variety of consumer energy needs, including continuous power, bac kup power, remote power, and peak shaving. They can be installed directly on the consumer's premises or located nearby in district energy systems, power parks, and mini-grids (Figure 4-10).
  
  Current research focuses on technologies that are powered by natural gas combustion and are located near the building or facility where the electricity is being used. These systems include microturbines, reciprocating engines and larger industrial gas turbines that generate from 25 kW to 10 MW of electricity that is appropriate for hotels, apartment buildings, schools, office buildings, hospitals, etc. Combined cooling, heating, and power (CHP) systems recover and use waste heat from distributed generators to efficiently cool, heat, or dehumidify buildings or make more power.
  
  Research is needed to increase the efficiency and reduce the emissions from microturbines, reciprocating engines, and industrial gas turbines to allow them to be sited anywhere, even in nonattainment areas. These technologies can meet a variety of consumer energy needs, including continuous power, backup power, remote power, and peak shaving. Microturbines and reciprocating engines can also be utilized to burn opportunity fuels such as landfill gases or biogases from wastewater-treatment facilities or other volatile species from industrial processes that would otherwise be an environmental hazard. [20]
  
  CHP technologies have the potential to take the DG technologies one step further in GHG reduction by utilizing the waste heat from the generation of electricity for making steam, heating water, or producing cooling energy. The average power plant in the United States converts approximately one-third of the input energy into output electricity and then discards the remaining two-thirds of the energy as waste heat. Integrated DG systems with CHP similarly produce electricity at 30 percent to 45 percent efficiency, but then capture much of the waste heat to make steam or heat, to cool water, or to meet other thermal needs and increase the overall efficiency of the system to greater than 70 percent. Research is needed to increase the efficiency of waste-heat-driven absorption chillers and desiccant systems to overall efficiencies well above 80 percent.
  
  The overall research goal of the Distributed Energy Program is to develop and make available, by 2015, a diverse array of high-efficiency, integrated distributed generation and thermal energy technologies, at market-competitive prices, so to enable and facilitate widespread adoption and use by homes, businesses, industry, communities, and electricity companies that may elect to use them. If successful, these technologies will enable the achievement of a 20 percent increase in a building's energy utilization, when compared to a building built to ASHRAE 90.1 standards, using load management, CHP, and energy-storage technologies that are replicable to other localities.
  

Research on energy storage is focused in two general areas. First, research is striving to develop storage technologies that reduce power-quality disturbances and peak electricity demand, and improve system flexibility to reduce adverse effects to industrial and other users. Second, research is seeking to improve electrical energy storage for stationary (utility, customer-side, and renewable) applications. This work is being done in collaboration with a number of universities and industrial partners. This work is set within an international context, where others are investing in high-temperature, sodium-sulfur batteries for utility load-leveling applications and pursuing large-scale vanadium reduction-oxidation battery chemistries.

The research program goals in this area focus on energy-storage technologies with high reliability and affordable costs. For capital cost, this is interpreted to mean less than or equal to those of some of lower-cost new power generation options ($400-$600/kW). Battery storage systems range from $300-$2,000/kW. For operating cost, this figure would range from compressed gas energy storage (which can cost as little as $1 to $5/kWh) to pumped hydro storage (which can range between $10 and $45/kWh). [21]

Research on sensors, controls, and communications focuses on developing distributed intelligent systems to diagnose local faults and coordinate with power electronics and other existing, conventional protection schemes that will provide autonomous control and protection at the local level. This hierarchy will enable isolation and mitigation of faults before they cascade through the system. The work will also help users and electric-power-system operators achieve optimized control of a large, complex network of systems; and will provide remote detection, protection, control, and contingency measures for the electric system.

The initial research program goals for sensors, controls, and communications are to develop, validate, and test computer simulation models of the distribution system to assess the alternative situations. Once the models have been validated on a sufficiently large scale, the functional requirements and architecture specifications can be completed. Then more specific technology solutions can be explored that would conform to the established architecture. [22]

Research on power electronics is focused on megawatt-level inverters, fast semiconductor switches, sensors, and devices for Flexible Automated Control Transmission Systems (FACTS). The Office of Naval Research and DOE have a joint program to develop power electronic building blocks. The military is developing more electricity-intensive aircraft, ships, and land vehicles, which are providing power electronic spinoff technology for infrastructure applications.

The research program goal in this area is to build a power electronic system on a base of modules. Each module or block would be a subsystem containing several components, and each one has common power terminals and communication connections. [23]

Future Research Directions

• High-Temperature Superconducting Cables and Equipment. The manufacture of promising HTS materials in long lengths at low cost remains a key program challenge. New, continuously-scanning analytical systems are necessary to ensure uniformly high superconductor characteristics over kilometer lengths of wire. Research and development could help develop highly reliable, high-efficiency cryogenic systems to economically cool the superconducting components including materials for cryogenic insulation and standardized high-efficiency refrigerators. Scale-up of national laboratory discoveries for "coated conductors" could be another promising area for the laboratories and their industry partners.
  
  
• Energy Storage. Energy storage that responds over timescales from milliseconds to hours-and outputs that range from watts to megawatts-is a critical enabling technology for enhancing customer reliability and power quality, more effective use of renewable resources, integration of distributed resources, and more reliable transmission system operation.
  
  
• Real-Time Monitoring and Control. Introduction of low-cost sensors throughout the power system is needed for real-time monitoring of system conditions. New analytical tools and software must be developed to enhance system observability and power flow control over wide areas.

4.5 Summary

As one illustration among the many hypothetical cases analyzed, [24] when a high-emissions constraint was placed on GHG emissions over the course of the 21st century, the lowest-cost arrays of advanced technology in end use and infrastructure, when compared to a reference case, resulted in 100-year cumulative reductions of emissions of roughly between 190 and 210 GtC. This amounted, roughly, to between 30 and 35 percent of all GHG emissions reduced, avoided, captured and stored, or otherwise withdrawn and sequestered, as needed to attain this level of constrained emission. Similarly, the costs for achieving such emissions reductions, when compared to the reference case, were reduced by roughly a factor of 3. See Chapter 3 for other cases and other scenarios.

As described in this chapter, CCTP's technology development strategy supports potential achievements in this range. The overall strategy is summarized schematically below in Figure 4-11. Advanced technologies are seen entering the marketplace in the near, mid, and long terms, where the long term is sustained indefinitely. Such a progression, if successfully realized worldwide, would be consistent with attaining the end use and infrastructure potential portrayed in Figure 3-19.

The timing and the pace of technology adoption are uncertain and must be guided by science. In the case of the illustration above, the first GtC per year (1GtC/year) of reduced or avoided emissions, as compared to a reference case, would need to be in place and operating, roughly, between 2030 and 2050. For this to happen, a number of new or advanced end-use and infrastructure technologies would need to penetrate the market at significant scale before these dates. Other cases would suggest faster or slower rates of deployment, depending on assumptions. See Chapter 3 for other cases and other scenarios.

Throughout Chapter 4, the discussions of the current activities in each area support the main components of this approach to technology development. The activities outlined in the current portfolio sections address the highest-priority investment opportunities for this point in time. Beyond these activities, the chapter identifies promising directions for future research, identified in part by the end-use and infrastructure technical working group and assessments and inputs from non-Federal experts. CCTP remains open to a full array of promising technology options as current work is completed and changes in the overall portfolio are considered.

Figure 4-11 Technologies for Goal #1: Reduce Emissions from End Use and Infrastructure (Note: Technologies shown are representations of larger suites. With some overlap, "near-term" envisions significant technology adoption by 10 to 20 years from present, "mid-term" in a following period of 20-40 years, and "long-term" in a following period of 40-60 years. See also List of Acronyms and Abbreviations.) (Download PDF)

References

Energy Information Administration (EIA). 2004. Annual energy outlook 2004: with projections to 2025, DOE/EIA-0383(2004). Washington, DC: U.S. Department of Energy.

Energy Information Administration (EIA). 2005. Annual energy outlook 2005: with projections to 2025, DOE/EIA-0383(2005). Washington, DC: U.S. Department of Energy.

Intergovernmental Panel on Climate Change (IPCC). 2000. Special report on emissions scenarios. Cambridge, UK: Cambridge University Press.

Intergovernmental Panel on Climate Change (IPCC). 2001. Climate change 2001: mitigation. Working Group III to the Third Assessment Report. Cambridge, UK: Cambridge University Press.

International Energy Agency (IEA). 2004. World energy outlook. Paris: International Energy Agency.

United Nations (UN) Population Division. 2005. World population prospects: the 2004 revision population database.

U.S. Climate Change Technology Program (CCTP). 2005. Technology options for the near and long term. Washington, DC: U.S. Department of Energy.

U.S. Department of Energy (DOE). 1997. Technology opportunities to reduce U.S. greenhouse gas emissions. Washington, DC: U.S. Department of Energy.

U.S. Department of Energy (DOE). 2002. National transmission grid study. Washington, DC: U.S. Department of Energy.

U.S. Department of Energy (DOE). 2005. Hydrogen fuel cells and infrastructure technologies multi- year research, development and demonstration plan: 2003-2010 (Draft). Washington, DC: U.S. Department of Energy.

U.S. Department of Energy (DOE), Energy Efficiency and Renewable Energy (EERE). 2005. FY 2006: budget-in-brief.

U.S. Department of Transportation (DOT). 2002a. Highway statistics 2001. Washington, DC: Federal Highway Administration.

U.S. Department of Transportation (DOT). 2002b. Freight analysis framework. Washington, DC: Federal Highway Administration.

U.S. Environmental Protection Agency (EPA). 2005. Inventory of U.S. greenhouse gas emissions and sinks: 1990-2003. EPA 430-R-05-003.

Footnotes

2 End use reduction includes improvements in energy efficiency in the end-use sectors, as well as improvements in efficiency of energy conversion, e.g., increased efficiency in electricity generation.

3 Visit US Climate Change Technology Program.

4 For more information, see Section 1.1.1 (CCTP 2005). See also: US Department of Energy, and US Environmental Protection Agency.

5 See Section 1.1.2 (CCTP 2005). See also: U.S. EPA Clean Automotive Technology.

6 See Section 1.1.3 (CCTP 2005).

7 See Section 1.1.4 (CCTP 2005).

8 See Section 1.1.5 (CCTP 2005).

9 According to the Annual Energy Review 2004, residential primary energy use increased 53 percent from 1970 to 2004, while the nation's population increased 44 percent over the same period. Commercial energy use increased 111 percent over this period, driven (in part) by the nearly 200 percent increase in real Gross Domestic Production (GDP).

10 See Section 1.2.2 (CCTP 2005).

11 See Section 1.2.1 (CCTP 2005).

12 See Section 1.2.3 (CCTP 2005).

13 Emissions of GHGs other than CO₂ from industry and agriculture are discussed in Chapter 7, "Reducing Emissions of Other Greenhouse Gases."

14 See Section 1.4.1 (CCTP 2005).

15 See Section 1.4.3 (CCTP 2005).

16 See Section 1.4.4 (CCTP 2005).

17 For more information, see Section 1.4.2 (CCTP 2005).

18 See Section 1.3.1 (CCTP 2005).

19 See Section 1.3.2 (CCTP 2005).

20 See Section 1.3.3 (CCTP 2005).

21 See Section 1.3.4 (CCTP 2005).

22 See Section 1.3.5 (CCTP 2005).

23 See Section 1.3.6 (CCTP 2005).

24 In Chapter 3, various advanced technology scenarios were analyzed for cases where global emissions of GHGs were hypothetically constrained. Over the course of the 21st century, growth in emissions was assumed to slow, then stop, and eventually reverse in order to ultimately stabilize GHG concentrations in the Earth's atmosphere at levels ranging from 450 to 750 ppm. In each case, technologies competed within the emissions-constrained market, and the results were compared in terms of energy (or other metric), emissions, and costs.