America's Energy Future Technology and Transformation (2009) / Chapter Skim
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4 Energy Efficiency
4 Energy Efficiency
Pages 135-210
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From page 135... ...
. But given the energy-security concerns over oil imports, recent volatility in energy prices, and the greenhouse gas emissions associated with energy consumption, using energy more efficiently has become an important priority.
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In reality, fuel economy may not come into the picture at all. Although energy and cost savings might be achievable with only a low first cost (investment)
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28 percent in transportation activities, and about 41 percent in the myriad activi ties and services associated with residential and commercial buildings. Figure 4.2 provides more detail, breaking out energy consumption by source and sector and also defining "primary" energy.
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Commercial Buildings 19% (18.5 Quads) Industry 31% (31.3 Quads)
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Other Industry Transportation 48% 4% Petroleum 28% Natural Gas 26% Electricity Buildings 34% 48% Energy Consumption by Source: Transportation Petroleum Consumption by Sector (Total: 28 Quads) (Total: 39.7 Quads)
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From page 140... ...
In the transportation sector, the committee focused on alterna tive technologies that could power the nation's cars and light trucks. By estimating the costs and energy savings associated with each technology as R&D improved 2Although greenhouse gas emissions are the primary environmental impact considered here, it should be noted that the evaluation of a specific application of a technology or measure should consider any other effects, including local effects, on the environment and natural resources.
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The committee examined other technologies, although in less detail. For each sector, comparisons were made to a baseline, or business-as-usual, case in order to derive the potential for energy savings.
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However, a large fraction of commercial buildings still have not embraced common energy efficiency measures such as energy management and control systems. The adoption of ENERGY STAR®-labeled products has also grown substan tially in recent years.
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approach to improving energy efficiency considers the energy consumption, and the set of improvements that could save energy, for entire buildings. It accounts for the ability to reduce energy use through design considerations such as incorporation of
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From page 144... ...
There are examples in Europe of new residences that have achieved even lower levels of energy consumption.4 For commercial buildings, several studies have reviewed the small but growing number of structures that have achieved 50 percent reductions in the energy needed for heating, cooling, and water heating. Most of these buildings have relied on High-efficiency electrical lighting systems, which use state-of-the-art lamps, ballasts, and luminaires (complete lighting fixtures)
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.7 Each measure is evaluated not in isolation but in the context of the measures that have already been taken. Most of the studies reviewed for this report relied on the technology-by-technology approach to develop supply curves for both residential and commercial buildings.
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Figures 4.3 through 4.6 are the supply curves developed for this study. They illustrate the potential for energy efficiency improvements over the period 2010– 2030 in the residential and commercial sectors for electricity and natural gas.
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FIGURE 4.4 Residential natural gas savings potential, 2030. Source: Brown et al., 2008.
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That the results show an average CCE well below the retail energy prices in all areas means that adopting efficiency measures is very cost-effective for house holds and businesses: the average CCE for electricity-savings measures is only about one-quarter of the average retail electricity price. Of course, factors such as local energy prices and weather will influence cost-effectiveness in any particular location.
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From page 149... ...
They include discrete technologies such as solid-state lighting, advanced windows, and high-efficiency air-conditioning equipment as well as the full integration of technologies into new and highly efficient buildings, both residential and commercial. These technologies demonstrate that energy efficiency is a dynamic resource new and improved alternatives now under development will reach the marketplace in the future, thereby increasing the potential for energy efficiency and energy savings.
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Technologies to Reduce Energy Consumption in Home Electronics Consumer products dealing with information processing are responsible for about 13 percent of residential electricity use (Roth and McKenney, 2007; EIA, 2008)
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The second advance is a new generation of dynamic products that reduce cooling loads and electric illumination when daylighting is available in commercial buildings. The full penetration of these advanced technologies into the building stock, which could take decades, might shift the role of windows in buildings to being approximately "energy neutral." Low-Energy and Zero-Net-Energy New Homes It is possible to construct homes that combine high levels of energy efficiency -- in the building envelope, heating and cooling systems, and appliances -- with passive and active solar features in order to approach zero-net-energy consumption.9 The whole-building approach described earlier is being used by the DOE to reach a zero-net-energy consumption goal.
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In particular, policies that allow public utilities to increase their profits by selling more electricity or natural gas are disincentives to effective utility energy efficiency programs (Carter, 2001)
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. Some highly efficient appliances or other energy efficiency measures are relatively new and still not widely available in the marketplace or not well supported by product providers (Hall et al., 2005)
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Likewise, many energy efficiency measures provide nonenergy benefits that encourage their adoption. In addition, public policies -- including building energy codes, appliance efficiency standards, and state and utility efficiency programs -- are stimulating greater adoption of effi ciency measures.
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There are substantial barriers to widespread energy efficiency improvements in buildings, but a number of factors are counteracting these barriers. Drivers of increased energy efficiency include rising energy prices; growing concern about global climate change and the resulting willingness of consumers and businesses to take action to reduce emissions; more consumers moving toward "green buildings"; and growing recognition of the significant nonenergy benefits offered by energy efficiency measures.
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Transportation energy consumption is also influenced by the physical net works of infrastructure through which vehicles move; by the logistic, institutional, 14Bureau of Transportation Statistics, National Transportation Statistics. Available at www.
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Potential for Energy Efficiency Improvements in Passenger Transportation Automobiles account for the vast majority of local and medium-distance passenger-trips17 (those under 800 miles) ; airlines dominate for longer trips.
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20As used here, "fuel consumption" is the inverse of fuel economy -- that is, the amount of fuel consumed in traveling 1 mile (or some other distance)
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. There are opportunities for further efficiency improvements that could reduce the fuel consumption of new diesel-engine vehicles relative to current diesel vehicles by about 10 percent by 2020 and an additional 10–15 percent by 2030.
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Several scientific, engineering, and business challenges must be met before hydrogen FCVs can be successfully com mercialized.21 The principal challenges are to increase the durability and lower the costs of fuel cells, achieve cost-effective storage of hydrogen in fueling stations and on board vehicles, and deploy a hydrogen sup ply and fueling infrastructure with low greenhouse gas emissions. These vehicles offer tremendous potential for reductions in oil imports and CO2 emissions in the long term (beyond 2035)
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Given that these vehicles will be sold in large quantities in the near term, it is critical that efficiency improvements in these vehicles not be offset by increased power and weight. While the current hybrids appear less competitive than a comparable diesel vehicle, they are likely to become more competitive over time, in part because hybrids can deliver greater absolute emission reduction than diesel vehicles can.
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Plug-in HEVs (PHEVs) and BEVs require significant energy storage (along with sufficient power)
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has established a set of long-term performance goals for electrochemical energy storage devices: • The target for PHEV batteries is an energy storage capacity of 11.6 kWh with an energy density of 100 Wh/kg and a unit cost of stored energy of $35/kWh. • The target for BEV batteries is an energy storage capacity of 40 kWh with an energy density of 200 Wh/kg and a unit cost of stored energy of $100/kWh.
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Greenhouse gas emissions from hydrogen production are estimated for hydrogen made from natural gas. bThe metric "vehicle petroleum consumption" is not applicable to vehicles powered by batteries and hydrogen fuel cells.
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market shares of advanced technologies can grow, such as the need for breakthroughs in battery performance and for a hydrogen-distribution infrastructure. Table 4.5 shows the AEF Committee's judgment, based on the constraints just outlined, of the extent to which these advanced vehicle technologies could plausibly penetrate the new LDV market in the United States.
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requires CAFE standards to be set for LDVs through 2020 in order to ensure that the industry-wide average fuel economy by that time is at least 35 mpg. This would be a 40 percent increase over today's average of 25 mpg.22 The AEF Committee examined two scenarios to explore how the deployment of the advanced technologies listed in Table 4.3, together with vehicle-efficiency improvements (such as reductions in vehicle weight, aerodynamic drag, and tire rolling resistance)
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Based on the estimated fuel consumption characteristics of individual vehicle types, shown in Table 4.3, and the fleet efficiency improvements represented in the scenarios, Table 4.6 shows examples of the sales mixes and weight reduction that would be required to meet the CAFE targets and to meet the scenario assumptions beyond 2020. Figure 4.7 shows, for the two scenarios, the corresponding annual gasoline consumption of the U.S.
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Neither of these scenarios includes BEVs or FCVs. a he amount of the efficiency improvement that is dedicated to reducing fuel consumption (i.e., that is not offset by increases in vehicle power, size, and weight)
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gallons/year) Optimistic scenario 21 86 Conservative scenario 16 66 Note: The no-change baseline assumes no change in average new-vehicle fuel consumption, a constant ratio of light trucks versus cars, and a 0.8 percent compounded annual growth in new-vehicle sales.
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Potential Energy Efficiency Improvements in Freight Transportation The movement of freight represents about 6–7 percent of the U.S.
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Rail is much more energy-efficient than trucking is; thus, enhancing the quality of rail services and facilitating intermodal transfers should lead to significant gains in freight-transport energy efficiency. In passenger transport, the opportunities for systemic approaches to improve energy efficiency may be even greater.
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Barriers to Improving Energy Efficiency in Transportation Numerous factors hinder the improvement of energy efficiency and the reduction of fuel consumption in passenger and freight transportation. Some of the most important are noted in the following list: In the United States, many factors -- including a century of falling energy prices and rising incomes, together with personal preferences and some government policies -- have contributed to decentralized land-use pat terns and a transportation-intensive economy.
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A continued decrease in fuel consumption (and associated greenhouse gas emissions) beyond 2020, when the EISA standards must be met, will require that the historic emphasis on ever-increasing vehicle power and size virtually be abandoned.
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Reduc tions of 10–20 percent in the fuel economy of heavy- and medium-duty vehicles appear feasible over a decade or so. Meanwhile, a broad examination is needed of the potential for further reductions in energy consumption stemming from improved freight-system effectiveness.
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U.S. industrial energy use is substantial: 31.3 quads of primary energy in 2008 (almost a third of the national total)
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industrial sector increased by nearly 45 percent, while total energy use was virtually unchanged; this led to a decrease in energy intensity by nearly a third. However, this apparent improvement in energy intensity was due primarily to a change in the mix of products manufac tured in the United States rather than to improvements in energy efficiency.
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State-level and international assessments of industrial energy efficiency potential are drawn on as well in the following paragraphs. Two major studies have estimated the potential for energy savings in U.S.
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b6.3 percent of the 2.311 quads of energy consumption forecast for the paper industry in 2020 by EIA (2008)
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Looking beyond 2020, a wide array of advanced industrial technologies could make significant contributions to reducing industrial energy consumption and CO2 emissions. Possible revolutionary changes include novel heat and power sources, as well as innovative processes for new products that take advantage of developments in nanotechnology and micro-manufacturing.
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; analyses of individual refining processes estimate energy savings ranging from 23 to 54 percent (DOE, 2006a)
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. More generally, membrane and advanced filtration methods could effect significant reductions in the total energy consumption of the pulp and paper industry (ORNL and BCA, Inc., 2005)
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Energy consumption per ton of steel has decreased 27 percent since 1990, while CO2 emissions fell by 16 percent. For 2002–2005, energy intensity per ton of steel decreased by 12 percent.
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The most attractive available energy efficiency technologies, with potential energy savings of 10–20 percent, derive from changing the chemistry of cement to reduce the need for calcination. Blended cements include higher proportions of other cementitious materials, such as fly ash.
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Specifically, imple mentation of all established motor-system energy efficiency technolo gies and practices that meet reasonable investment criteria could yield annual energy savings of 75–122 billion kWh. A next generation of motor and drive improvements is on the horizon, including motors with high-temperature superconducting materials that could extend savings much further.
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. Summary of Potential Energy Savings in Industry Table 4.10 summarizes the potential energy savings stemming from energy efficiency improvements in industry.
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Relatively high costs. Because new technologies often have longer pay back periods than does energy-efficient traditional equipment, they represent a more serious financial risk, given uncertainty about future energy prices.
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In some cases, industrial managers are simply unaware of energy efficiency opportunities and low-cost ways to implement them. This barrier is made more onerous by the limited governmental collection and analysis of data on energy use in the industrial sector.
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Investments in industrial energy efficiency technologies are hindered by market risks caused by uncertainty about future electricity prices, natu ral gas prices, and unpredictable long-term product demand. Addition ally, industrial end-use energy efficiency faces unfavorable fiscal policies.
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However, investment in an upgrade could trigger an NSR, and the threat of such a review has prevented many upgrades from occurring. Drivers for Improving Energy Efficiency in Industry Helping to overcome the barriers to improving energy efficiency in industry is a set of motivators that include the following: Rising energy prices and fuel/electricity availability.
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industry (EIA, 2008) , 14–22 percent could be saved through cost-effective energy efficiency improvements (those with an inter nal rate of return of at least 10 percent or that exceed a company's cost of capital by a risk premium)
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Summarized in the following list, the barriers include: Limited supply and availability of some energy efficiency measures, such as newer products manufactured on a limited scale or not yet widely marketed; Lack of information, or incomplete information, on energy efficiency options for businesses, households, and other venues; Lack of funds to invest in energy efficiency measures, often resulting from constraints imposed within the financial system rather than from the financial inability of the would-be user to raise capital; Fiscal or regulatory policies that discourage energy efficiency invest ments, often inadvertently;
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Vehicle Efficiency Standards The United States adopted energy efficiency standards for cars and light trucks, known as CAFE standards, in 1975. These standards played a leading role in the near-doubling of the average new-car fuel economy and the 55 percent increase in the fuel economy of light trucks from 1975 to 1988 (Greene, 1998)
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. In 1992, minimum efficiency standards were extended to motors, heating and cooling equipment used in commercial buildings, and some types of lighting products.
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. Building Energy Codes Most state and local authorities have adopted mandatory energy codes for new houses and commercial buildings, often following models such as the International Energy Conservation Code, although some state or local codes are more stringent.
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. Based in part on this experience, new tax credits were enacted in 2005 for innovative energy efficiency measures that included hybrid, fuel-cell and advanced diesel vehicles, highly efficient new homes and commercial buildings, and very efficient appliances.
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. It is estimated that the use of CHP systems resulted in total energy savings of about 2.8 quads in 2006, with perhaps 60 per cent attributable to the Public Utilities Regulatory Policies Act (PURPA)
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Increasing energy prices, ongoing technological change, and structural change have also contributed to the steep decline in energy intensity in the past 35 years. Comparing energy savings across the various policies and programs listed in Table 4.11, regulatory initiatives such as the CAFE standards, appliance efficiency standards, and PURPA provided the greatest amount of energy savings.
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, and assuming that 75 percent of the energy savings from vehicle efficiency improvements are due to the CAFE standards. bExtrapolates between savings estimates by ACEEE for 2000 and 2010.
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Source: Energy Information Administration, State Energy Consumption, Price, and Expenditure Estimates, available at www.eia.doe.gov/emeu/states/_seds.html. California As shown in Figure 4.8, California maintained nearly flat per capita electricity consumption from 1975 to the present.
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Califor nia's investor-owned utilities spent in excess of $600 million per year to promote more efficient electricity use by their customers as of 2007.26 They can now earn a profit on these expenditures through the performance-based incentive program. The combination of appliance standards, building energy codes, and utility efficiency incentives has resulted in considerable electricity savings in California.
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Minimum efficiency standards can be a very effective strategy for stimulating energy efficiency improvements on a large scale, especially if the standards are periodically updated. Such standards should not only be technically and economically feasible but also provide manufacturers with enough lead time to phase out production of nonqualifying products in an orderly manner.
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These energy efficiency improvements would save money as well as energy. There are formidable barriers to improving energy efficiency.
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2006. Window-Related Energy Consumption in the US Residential and Commercial Building Stock.
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2001. Scenarios for a clean energy future.
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2009. 2006 Manufacturing Energy Consumption Survey.
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2007. Energy efficiency improvements that use the best available technologies and practices and integrated whole-building design approaches can, on average, reduce energy consumption by 43%.
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2000. Scenarios for a Clean Energy Future.
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2002. Effectiveness and Impact of Corporate Average Fuel Economy (CAFE)
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2007. Energy Consumption by Consumer Electronics in U.S.
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Stock turnover, retrofit, and industrial energy efficiency. Energy Policy 33:949-962.
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