Real Prospects for Energy Efficiency in the United States (2010) / Chapter Skim
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1 Energy Use in Context
1 Energy Use in Context
Pages 21-40
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It describes the technologies' state of development; the potential for their use to achieve energy savings in buildings, transportation, and industry; and their performance, costs, and environmental impacts, most notably emission of greenhouse gases.2 The panel was convened as part of the National Academies' America's Energy Future (AEF) project (described in Appendix A)
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In 2008 it used 99.4 quadrillion Btu (99 quads) of primary energy (Figure 1.1)
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20 Petroleum Natural Gas 15 Coal Renewables 10 5 0 Residential Commercial Industrial Transportation FIGURE 1.2 Total energy consumption in the United States in 2008, by sector and fuel. Shown are electricity consumption -- with the losses in generation, transmission and distribution allocated to the end-use sectors -- and the fuels used on-site in each sector.
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Source: Lawrence Livermore National Laboratory and the U.S. Department of Energy, based on data in the Annual Energy Review 2008 (EIA, 2009a)
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energy intensity -- the amount of energy used per dollar of gross domestic product (GDP) -- has fallen steadily over many decades, with the exception of 1890 to 1920 and a few years after 1945 (Figure 1.4)
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But if energy intensity continued to drop by 2.1 percent per year, by 2030 the energy intensity of the U.S. economy could be 30 percent lower than it is today, and total energy use in 2030 would increase by only 8.7 percent.
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The first period receives major attention because so many cost-effective technologies are ready for implementation today or will be ready within a few years. The panel examined the literature on energy
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Correcting for structural differences, the International Energy Agency has shown that between 1973 and 1998 the energy intensity of the United States and the eight major European economies fell 34 percent, and the energy intensity of Japan fell 30 percent (IEA, 2004)
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The second bar indicates what each country's overall energy intensity would be if it had the average economic structure of the nations shown but its existing set of energy intensities. The third bar represents what the overall energy intensity would be if a country kept its own economic structure but had the energy intensities of the average among the nations shown.
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of electricity per year relative to today's consumption, or nearly 6 percent of the total amount of electricity generated in the United States. Overall Coal Efficiency = 1.3% Power Plant Transmission Lines Light E1 = 0.35 E2 = 0.90 E3 = 0.04 Overall Efficiency for = E1 × E2 × E3 Conversion of Chemical Energy = 0.35 × 0.90 × 0.04 = 0.013 to Light Energy FIGURE 1.2.1 Example of how end-use efficiency influences overall fuel conversion efficiency.
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While both the CFL and LED save money and energy, compared with the incandescent lamp, whether the LED saves money compared with the CFL is sensitive to the number of hours each year the lamp is used, the purchase price, and the discount rate. 3The United States emitted 5.89 billion metric tons of CO in 2006 as a result of all energy 2 consumption.
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For exam ple, landlords of rental residential buildings are not motivated to pay for more develop illustrative scenarios of how total energy consumption in the light-duty vehicle (LDV) fleet could evolve.4 For industry, the panel focused on the four most 4Technologies to increase the fuel efficiency of LDVs (automobiles and light trucks)
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• Energy-savings investments by businesses and industries are not always seen as beneficial. If energy accounts for only a small part of total costs, or if the avail able capital is limited, other investments may be preferred -- e.g., in reducing other costs, improving products, or developing new ones.
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primary energy consumption are given in Box 1.5. Distinguishing between primary and delivered energy is most useful for electricity, where the difference between 5With an assessment of whether the results might have differed if the EIA's Annual Energy Outlook 008 had been used.
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, the panel S derived illustrative cutting technologies scenarios of overall savings in fleet fuel consumption Key cost- Levelized cost of energy Recovery of discounted Energy savings provide effectiveness savings is less than the costs of energy savings an internal rate of return over the life of an LDVc criteria national average electricity on investment of at least and natural gas prices 10 percent or exceed the company's cost of capital by a risk premium Technology Technology specific Average vehicle lifetime Technology specific lifetimes Before-tax 7 7 15 discount rate (%, annual) Other Assessment accounts for stock For LDVs, assessment Assessment of savings in considerations turnover in buildings and considers how the specific industries used equipment distribution of specific to confirm industry-wide vehicle types in the new- estimates vehicle fleet affects the on the-road fleet aManufacturing only.
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Energy intensity can also represent the amount of energy used per dollar of outputor, for the whole economy, per dollar of gross domestic product (GDP)
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using the heat rate for nuclear plants • Conventional hydroelectricity net generation, converted to Btu using the heat rate for fossil-fueled plants • Geothermal electricity net generation, converted to Btu using the heat rate for geothermal plants, and geothermal heat-pump energy and geothermal direct-use energy • Solar thermal and photovoltaic electricity net generation, converted to Btu using the heat rate for fossil-fueled plants, and solar thermal direct-use energy • Wind electricity net generation, converted to Btu using the heat rate for fossil-fueled plants • Wood and wood-derived fuels • Biomass waste (municipal solid waste from biogenic sources, landfill gas, sludge waste, agricultural byproducts, and other biomass) • Fuel ethanol and biodiesel; losses and co-products from the production of fuel ethanol and biodiesel • Electricity net imports, converted to Btu using the electricity heat content of 3412 Btu/kWh.
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used directly at a site to arrive at a total value for "delivered energy" use at a site. This approach can lead to misleading conclusions -- for example, that an all-electric building with resistance heating uses less energy than a comparable building with gas heated, because the delivered electricity, as measured in Btu, can be lower than the Btu value of the delivered natural gas.
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U.S. Lighting Market Characterization, Volume 1, National Lighting Inventory and Energy Consumption Estimates.
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2008. An Examination of Energy Intensity and Energy Efficiency.
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