6
Hydrogen and Alternative Technologies for Reduction of U.S. Oil Use and CO2Emissions

Estimating future transportation fuel use is difficult because of the complexities and uncertainties inherent in the analysis. Petroleum may continue to be the dominant fuel, or production may become constrained and prices rise much further. Hydrogen may replace petroleum as the main fuel, or it may not become significant at all. As discussed in Chapter 3, fuel cell vehicles and hydrogen have the potential to become competitive with conventional vehicles and fuels, but it is far from certain when that might be. Competitiveness depends in part on the cost of petroleum, which itself is highly uncertain, as witnessed by recent dramatic escalations in world oil prices. Nevertheless, as discussed in Chapter 2, there appear to be compelling reasons why the nation may have to reduce its use of petroleum, and hydrogen is among the leading candidates proposed to achieve dramatic reductions. Moving to a hydrogen-based transportation sector would be a revolutionary change that is unlikely to happen by itself. Mapping a route is essential to understanding how such a change might happen. Toward that end, this chapter formulates and analyzes several scenarios to map plausible futures for the use and impacts of hydrogen fuel cell vehicles (HFCVs) and other alternative vehicles and fuels. The scenarios and analyses necessarily depend on a host of assumptions. None of the scenarios should be viewed as projections of what the committee thinks is likely to happen. Rather, they are intended to describe different paths along which events may unfold and the consequences, especially for oil consumption and carbon dioxide emissions.

SCENARIOS AND ANALYSIS

Scenarios

The main object of the scenario analysis is to estimate the maximum practicable penetration rate of fuel cell vehicles, and then to estimate the resulting reductions of petroleum use and emissions of carbon dioxide (CO2) in 2020 and beyond; period to bring hydrogen fuel cell vehicle technologies to cost competitiveness with gasoline vehicle technology; and the costs for a future hydrogen infrastructure. The committee developed three scenarios in order to investigate the range of possible outcomes. The hydrogen scenario analyses are based on the results presented in Chapter 3. In addition, as discussed in Chapter 4, hydrogen is not the only way to reduce petroleum use. Two scenarios focused on alternatives are analyzed, and a final scenario looks at combining all the approaches.

  • Case 1 (Hydrogen Success) assumes that development programs are successful, as shown in Table 6.1, and that policies are implemented to ensure commercial deployment. Hydrogen fuel cell vehicles are introduced starting with a few thousand vehicles in 2012, growing to a fleet of almost 2 million by 2020, 60 million in 2035, and 220 million in 2050 (Figure 6.1). This rapid-growth case corresponds to a scenario recently developed by the U.S. Department of Energy (DOE) to 2025 (Gronich, 2007) and extended by the committee to 2050. By 2050, 80 percent of new vehicles sold are assumed to be HFCVs (Figure 6.2). This is consistent with other recent modeling studies (Greene et al., 2007).

    • Case 1a (Hydrogen Accelerated) assumes that hydrogen and fuel cell vehicles are introduced at twice the rate of Case 1, although technical and cost goals are met at the same rate as Case 1. By 2020, 4 million hydrogen fuel cell vehicles are in the fleet. By 2050, 95 percent of new vehicles sold are assumed to be HFCVs This case is intended to investigate whether hydrogen could replace even more oil than in Case 1 if the nation faces a crisis situation, perhaps from declining worldwide petroleum production or rapidly worsening global climate change.

    • Case 1b (Hydrogen Partial Success) assumes that developing programs fall short of the costs and performance of Case 1 (Hydrogen Success). Thus, the market introduction rate is slower than for Case 1, similar to DOE’s “Scenario the investments that would be needed during a transition 1” (Gronich, 2007). By 2020, fewer than 1 million HFCVs



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6 hydrogen and alternative Technologies for reduction of U.s. oil Use and co2 emissions Estimating future transportation fuel use is difficult period to bring hydrogen fuel cell vehicle technologies to because of the complexities and uncertainties inherent in cost competitiveness with gasoline vehicle technology; and the analysis. Petroleum may continue to be the dominant the costs for a future hydrogen infrastructure. The committee fuel, or production may become constrained and prices rise developed three scenarios in order to investigate the range much further. Hydrogen may replace petroleum as the main of possible outcomes. The hydrogen scenario analyses are fuel, or it may not become significant at all. As discussed in based on the results presented in Chapter 3. In addition, Chapter 3, fuel cell vehicles and hydrogen have the potential as discussed in Chapter 4, hydrogen is not the only way to to become competitive with conventional vehicles and fuels, reduce petroleum use. Two scenarios focused on alternatives but it is far from certain when that might be. Competitive- are analyzed, and a final scenario looks at combining all the ness depends in part on the cost of petroleum, which itself is approaches. highly uncertain, as witnessed by recent dramatic escalations • Case 1 (Hydrogen Success) assumes that development in world oil prices. Nevertheless, as discussed in Chapter 2, there appear to be compelling reasons why the nation may programs are successful, as shown in Table 6.1, and that have to reduce its use of petroleum, and hydrogen is among policies are implemented to ensure commercial deployment. the leading candidates proposed to achieve dramatic reduc- Hydrogen fuel cell vehicles are introduced starting with a tions. Moving to a hydrogen-based transportation sector few thousand vehicles in 2012, growing to a fleet of almost would be a revolutionary change that is unlikely to happen 2 million by 2020, 60 million in 2035, and 220 million in by itself. Mapping a route is essential to understanding how 2050 (Figure 6.1). This rapid-growth case corresponds to such a change might happen. Toward that end, this chapter a scenario recently developed by the U.S. Department of formulates and analyzes several scenarios to map plausible Energy (DOE) to 2025 (Gronich, 2007) and extended by the futures for the use and impacts of hydrogen fuel cell vehicles committee to 2050. By 2050, 80 percent of new vehicles sold (HFCVs) and other alternative vehicles and fuels. The sce- are assumed to be HFCVs (Figure 6.2). This is consistent narios and analyses necessarily depend on a host of assump- with other recent modeling studies (Greene et al., 2007). tions. None of the scenarios should be viewed as projections —Case 1a (Hydrogen Accelerated) assumes that hydro- of what the committee thinks is likely to happen. Rather, gen and fuel cell vehicles are introduced at twice the rate of they are intended to describe different paths along which Case 1, although technical and cost goals are met at the same events may unfold and the consequences, especially for oil rate as Case 1. By 2020, 4 million hydrogen fuel cell vehicles consumption and carbon dioxide emissions. are in the fleet. By 2050, 95 percent of new vehicles sold are assumed to be HFCVs This case is intended to investigate whether hydrogen could replace even more oil than in Case sceNarios aNd aNalYsis 1 if the nation faces a crisis situation, perhaps from declin- ing worldwide petroleum production or rapidly worsening scenarios global climate change. The main object of the scenario analysis is to estimate the —Case 1b (Hydrogen Partial Success) assumes that maximum practicable penetration rate of fuel cell vehicles, developing programs fall short of the costs and performance and then to estimate the resulting reductions of petroleum use of Case 1 (Hydrogen Success). Thus, the market introduction and emissions of carbon dioxide (CO2) in 2020 and beyond; rate is slower than for Case 1, similar to DOE’s “Scenario the investments that would be needed during a transition 1” (Gronich, 2007). By 2020, fewer than 1 million HFCVs 

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 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN TABLE 6.1 Assumed Cost and Performance of Hydrogen Fuel Cell Vehicles and Gasoline Reference Vehicles a Case 1: Case 1b: Reference Hydrogen Hydrogen Gasoline ICEV Efficient Gasoline Success Partial Success (AEO 2008) ICEV (Case 2) FC drivetrain retail Costs fall with Costs fall with $54/kW $64/kW price (including learning and learning and fuel cell and manufacturing manufacturing hydrogen storage scale to $100/kW scale to $130/kW HFCV retail price >$100,000 >$100,000 — $1,000 (initially) → increment compared (initially)→ to gasoline $3,600 $6,100 reference vehicle (learned out) (learned out) FCV market 2012 (Case 1) 2015 — — Introduction 2010 (Case 1a) New car fuel 51 mpgge 45 mpgge 2005: 20.2 mpg 20.2 mpg (2015) → (2015) → economya 2015: 25.0 25.2 85 mpgge 73 mpgge 2050: 31.7 42.4 (2050) (2050) =  × efficient = . × efficient gasoline case gasoline case NOTE: Case 1a, Hydrogen Accelerated, is the same as Case 1, Hydrogen Success, for these values. Costs and fuel economy of HFCVs are based on a refer- ence midsize vehicle with an 80 kW fuel cell. While small relative to most current engines, this would give equivalent performance, in part because of weight reductions in the body. This vehicle is assumed to represent the range of vehicles from small to large. Given all the other uncertainties in this analysis and the limited resources available to the committee, this assumption was both reasonable and unavoidable. aOn-road fuel economy is assumed to be 80 percent of the EPA average. 400 1.2 Case 1 (H2 Success): Million light-duty vehicles 350 gasoline Case 1 (H2 1 Success): gasoline Case 1a (H2 Accel): 300 gasoline Case 1a (H2 Accel): 0.8 250 gasoline Case 1b (H2 Partial Fraction Success): gasoline 200 Case 1b (H2 Partial 0.6 Case 1 (H2 Success): Success): gasoline 150 HFCV 0.4 Case 1 (H2 100 Case 1a (H2 Accel): Success): HFCV HFCV 0.2 50 Case 1a (H2 Accel): Case 1b (H2 Partial HFCV 0 Success): HFCV 0 Case 1b (H2 Partial 2000 2010 2020 2030 2040 2050 TOTAL 2000 2010 2020 2030 2040 2050 Success): HFCV Year Year color Figure 6-1.eps FIGURE 6.1 Hydrogen cases: Number of gasoline and hydrogen FIGURE 6.2 Hydrogen cases: Fraction of new gasoline and hydro- color Figure 6-2.eps fuel cell vehicles in the fleet over time for three hydrogen cases. gen vehicles sold each year. • Case 3 (Biofuels) examines the large-scale use of bio- are on the road, about the same rate of market penetration as fuels production from crop and cellulosic feedstocks. This hybrid electric vehicles have experienced. • Case 2 (ICEV Efficiency) investigates the impact of level of production, equivalent to a maximum practical rate, is based on the results in Chapter 4. improving conventional internal combustion engine ICEV • Case 4 (Portfolio), “all of the above,” analyzes the fuel economy with currently feasible and expected technol- impact if HFCVs, more efficient conventional vehicles, and ogy. Fuel economy more than doubles by 2050, as shown in biofuels are all pursued simultaneously. Table 6.1, in the committee’s judgment the maximum practi- cal rate with evolutionary vehicle technology. This analysis is based on the results in Chapter 4.

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 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS TABLE 6.2 Hydrogen Supply Pathways Considered in This Analysis Hydrogen Production Hydrogen Delivery Method to Station Resource Technology (for Central Plants) Natural gas Steam methane reformation N/A (on-site)a Liquid hydrogen truck Steam methane reforming Compressed gas truck (central plant) Hydrogen gas pipeline Coal Coal gasification with carbon Liquid hydrogen truck capture and sequestration Compressed hydrogen gas truck (central plant) Hydrogen gas pipeline Biomass (agricultural, forest, Biomass gasification (central Liquid hydrogen truck and urban wastes) plant) Compressed hydrogen gas truck Hydrogen gas pipeline On-site reforming of ethanol N/A Electricity (from various electric Water electrolysis (on-site) N/A generation resources) NOTE: N/A = not applicable. aOn-site refers to hydrogen production at the refueling station. These scenarios are compared to a reference case, based (NRC) FreedomCar Fuel Partnership report (NRC, 2008). on the Energy Information Agency (EIA) 2008 Annual Available hydrogen supply pathways are listed in Table 6.2. Energy Outlook (EIA, 2008). The committee selected the Hydrogen production or storage technologies that would AEO high-oil-price scenario for its reference case as being require fundamental scientific breakthroughs (for example, more representative of conditions under which HFCVs hydrogen storage in carbon nanostructures or biological are promoted than the AEO reference case.1 This scenario production of hydrogen by algae) are not considered. includes improvements of gasoline ICEV technology to meet Cost and performance data for current and midterm CAFE (corporate average fuel economy) standards, although (2015-2030) hydrogen infrastructure technologies are dis- fuel economy continues to grow slowly after 2020, and some cussed in Chapter 3. Efficiency improvements in ICEVs and use of biofuels (blending up to 10 percent ethanol) but no biofuels are described in Chapter 4. introduction of hydrogen or advanced ICEV technology. Gasoline taxes continue as per AEO 2008. modeling Tools for scenario analysis The time frame for analysis is 2008 to 2050. The commit- tee agreed that HFCVs were not likely to make a large impact The committee developed two EXCEL-based models for on U.S. oil use and greenhouse gas emissions by 2020, infrastructure and scenario analysis: because they are unlikely to enter the market before 2012- 2018, and then it will take time to build up a large enough 1. Hydrogen infrastructure model: designs and costs number of vehicles to impact oil use and carbon emissions hydrogen infrastructure to meet a specified market penetra- significantly. The committee recognizes that uncertainties tion for HFCVs. increase in such a long-term analysis, but it was necessary 2. Simplified transition model: estimates investment to for examining the time frame during which hydrogen could bring HFCV costs to competitive levels, investment costs for have a large impact. building hydrogen infrastructure, oil savings, and greenhouse gas emission reductions,2 over time. Technologies considered The models were developed at the University of California Hydrogen and fuel cell technologies are based on tech- at Davis (UC Davis) and are described in detail in Appendix nologies currently in development, as discussed in Chapter C. Given the time and resources available to the committee, 3 and recently reviewed in the National Research Council the models were of necessity relatively simple, but they 1In this scenario, imported low-sulfur crude oil is projected to cost about 2Carbon $79 per barrel in 2010, rising to $90 in 2015, $102 in 2020, and $119 in dioxide is the main greenhouse gas of concern in this analysis, 2030 (all in 2006 dollars). Oil was over $130 per barrel in June 2008, but but other gases, especially methane and nitrous oxide, are emitted as part of that does not necessarily mean that the AEO numbers are wrong. Other the full fuel cycle. These are accounted for with global warming equivalency projections are both well above and well below this one. factors, taken from the literature and the GREET model.

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 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN TABLE 6.3 Assumptions in Reference Case 2005 2020 2035 2050 Total number of LDVs (millions) 220 280 331 369 Share of LDV fleet Gasoline ICEVs 99.8% 96.6% 93.2% 91.4% Gasoline hybrids 0.3% 3.4% 6.8% 8.6% New LDVs sold per year (millions) 16.2 18.2 20.8 22.4 Share of New LDVs per year Gasoline ICEVs 98.6% 94.7% 91.8% 91.1% Gasoline hybrids 1.4% 5.2% 8.2% 8.9% Average on-road fuel economy, new gasoline LDVs (mpg) Gasoline ICEVs 20.2 29.3 30.6 31.7 Gasoline hybrids 32.1 41.0 42.9 44.5 Gasoline price ($/gallon) 2.32 3.19 3.54 3.96 Vehicle-miles traveled (billion per year) 2,556 3,251 4,243 5,364 Gasoline consumed (billion gallons per year) 124 132 140 157 (includes blends of ethanol up to 10%) Ethanol (billion gallons per year) consumed as: Blend in gasoline to 10% 3.4 12.7 15.6 21 E 85 0.01 0.06 0.20 Greenhouse gas emissions (million tonnes CO2 equivalent per year) 1,345 1,442 1,527 1,710 were quite adequate for the purpose of scoping the potential on the DOE National Energy Modeling System (NEMS). For growth of HFCVs and their impact. input beyond 2030, a vehicle stock model was adapted from the Argonne National Laboratory VISION model to estimate numbers of LDVs, fuel economy, and vehicle energy use to modeling assumptions 2050 (Singh et al., 2003; Argonne, 2007). The vehicle stock • Only U.S. light-duty vehicles (LDVs) are considered. model keeps track of what vehicles are in the fleet (vehicles All scenarios assume the same total number of vehicles and are retired after a certain number of years) as increasing vehicle-miles traveled (VMT) as the reference case. numbers of hydrogen vehicles enter the market, allowing the • The AEO high-price case is used as the basis for energy calculation of energy use and greenhouse gas emissions for prices. each year. Table 6.3 and Figures 6.3 to 6.5 summarize the • The real discount rate is 15 percent (no inflation is reference case. After the committee had completed its initial included). analysis, Congress passed the Energy Independence and • The costs are given in 2005 constant dollars. Security Act of 2007 (EISA), which included a significant • Costs for hydrogen infrastructure technologies (hydro- increase in fuel economy standards for vehicles. The refer- gen production, storage, delivery, refueling stations) draw ence case reflects this new policy. heavily on DOE’s H2A database (DOE, 2007). Both current The reference case includes modest use of biofuels. In and 2015 technology numbers are used where available (for 2030, the reference case assumes that 15 billion gallons of production and refueling station technologies). ethanol are used per year, 12 billion from corn ethanol and 3 billion from cellulosic ethanol. This gradually increases to 21 billion gallons per year in 2050 (12 billion gallons from hYdroGeN sceNario aNalYsis corn, 9 billion gallons from cellulosic feedstocks). This is equivalent to about 8-10 percent ethanol by volume in gaso- reference case line after about 2020.3 Cases 1 through 4 (hydrogen and other alternative fueled 3EISA includes ambitious goals for biofuels as well as fuel economy. vehicle) are compared against a reference case. The reference The goal for 2020 is 36 billion gallons, of which 21 billion would be from case is based on the high-price case of the AEO (EIA, 2008), advanced processes, such as cellulosic ethanol. The committee decided not which gives projections to 2030 for vehicle miles traveled, to include these goals in its reference case for two reasons. First, the likeli- vehicle fuel economy, and vehicle fleet composition based hood of meeting the biofuel goals appears to be much lower than for fuel

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 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS 400 14 Million light-duty vehicles 350 Billion gallons per year 12 300 10 Gasoline ICEV 250 8 Corn ethanol Gasoline HEV 200 Cellulosic ethanol HFCV 6 150 Total 4 100 2 50 0 0 2000 2010 2020 2030 2040 2050 2000 2010 2020 2030 2040 2050 Year Year color Figure 6-5.eps FIGURE 6.5 Reference case: Assumed biofuel use. FIGURE 6.3 Reference case: Number of light-duty vehicles in color Figure 6-3.eps the fleet. • For Cases 1 (Hydrogen Success) and 1a (Accelerated 50 45 Hydrogen), the fuel cell drivetrain (the fuel cell system, 40 Fuel economy (mpgge) hybrid battery, motor, and auxiliaries) costs the automaker 35 (original equipment manufacturer, or OEM) $50/kW. This 30 corresponds to a fuel cell system cost of $30/kW plus added 25 20 costs for a hybrid battery, electric motor, and other compo- Gasoline ICE 15 nents. Of the $30/kW fuel cell system cost, about half is due Gasoline HEV 10 to the fuel cell stack and half to the balance of plant. Hydro- 5 gen storage costs the OEM $10/kWh. A model from Kromer 0 and Heywood (2007) shows the total OEM manufacturing 2000 2010 2020 2030 2040 2050 cost for drivetrain plus storage to be $71/kW, or a retail price Year of about $100/kW, giving a drivetrain plus storage price of FIGURE 6.4 Reference case: Assumed fuel economies for gasoline $7,920. ICEVs and gasoline hybrid vehicles (HEVs). (The “dip” in hybrid color Figure 6-4.eps • For Case 1b (Hydrogen Partial Success), the fuel cell fuel economy in 2004 occurred when hybrid sport utility vehicles drivetrain costs the OEM $62/kW corresponding to a fuel and vans entered the market.) cell system cost of $50/kW plus added costs for a hybrid battery, electric motor, and other components. Of the $50/kW fuel cell system cost, about 40 percent is due to the fuel cell stack and 60 percent to the balance of plant. Hydrogen storage costs $15/kWh. The total OEM manufacturing cost hydrogen cases 1, 1a, 1b is $93/kW or a retail price of about $130/kW, giving a drive- Table 6.1 lists cost and performance assumptions for train plus storage price of $10,400. hydrogen fuel cell vehicles and a gasoline reference vehicle for each hydrogen case. HFCV costs are based on an 80 The drivetrain and fuel storage for a reference gasoline kW fuel cell “engine” with 5 kg (165 kWh) of compressed internal combustion engine car are assumed to have an OEM hydrogen gas stored on board.4 (The drivetrain includes the cost of $35/kW plus $300 for the exhaust system. For an fuel cell and auxiliaries, a hybrid battery, electric motor, 80 kW engine, the OEM cost is $3,100 and the retail price wiring, and hydrogen storage.) This is consistent with the $4,300 ($54/kW). The price for each vehicle is broken down following assumptions: into a drivetrain and a “glider” (the rest of the vehicle). For all vehicles the glider price is the same, $18,750. The HFCV price is assumed to decrease according to a learning economy. Second, the net oil displacement and CO2 emission reduction are curve model developed by Oak Ridge National Laboratory much less certain than for fuel economy improvements. These factors are researchers (Greene et al., 2007), based on automobile discussed in Chapter 4. manufacturers’ estimates of fuel cell vehicle costs in mass 4The 2006 reference gasoline vehicle is based on a midsized five pas- senger car, with a curb weight of 1,570 kg. As efficiency improves over production (Figure 6.6). time, the weight is reduced to about 1,280 kg by 2030. The weight of the Cases 1 and 1a assume that the HFCV has twice the fuel corresponding HFCV is 1,320 kg, reflecting heavier components. This refer- economy of an efficient gasoline ICEV, described in Case 2 ence vehicle is about average for the current new car fleet and is assumed (ICEV Efficiency) below. (The evolving efficient gasoline to represent the fleet. Similarly, the HFCV that replaces it is assumed to be ICEV in Case 2 has fuel economy of 25.2 miles per gallon representative. HFCVs, like conventional vehicles, will range from small to large, but the fuel savings can still be determined from the average.

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$40,000 V $30,000 $20,000 2005 2010 2015 2020 2025 2030 2035 Year 8 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN Gasoline ICE Gasoline ICE HFCV $120,000 $120,000 $110,000 HFCV $110,000 $100,000 Vehicle first cost Vehicle first cost $100,000 $90,000 $90,000 $80,000 $80,000 $70,000 $70,000 $60,000 $60,000 $50,000 $50,000 $40,000 $40,000 $30,000 $30,000 $20,000 $20,000 2005 2010 2015 2020 2025 2030 2035 2005 2010 2015 2020 2025 2030 2035 Year Year FIGURE 6.6 Assumed retail prices for hydrogen and gasoline vehicles over time for Cases 1 and 1a (left) and Case 1b (right). Figure6-6.eps Gasoline ICE (mpg) in 2015 and 42.4 mpg in 2050). The hydrogen fuel cell 2007b). SSCHISM employs an idealized spatial model of vehicle has about 1.4 times the fuel economy of the gasoline infrastructure layout in cities to design and cost alternative $120,000 $110,000 hybrid in Case 2 (which is assumed to get 36.5 mpg in 2015 infrastructure pathways. Inputs include information about HFCV $100,000 Vehicle first cost and 60.3 mpg in 2050). In Case 1b (Hydrogen Partial Suc- the level of demand (market fraction of hydrogen vehicles), $90,000 cess), $80,000 vehicle has 1.75 times the fuel economy of the the fuel the city population and size, the number of stations, local $70,000 efficient gasoline ICEV. feedstock and energy prices, and constraints on viable types $60,000 Analysis of all three hydrogen cases is detailed in Appen- of supply. Outputs include the delivered hydrogen cost to $50,000 dix C.$40,000 (Hydrogen Partial Success) gave rise to only Case 1b the vehicle, hydrogen infrastructure costs, and energy use modest reductions in oil use and CO2 emissions by 2050. and CO2 emissions for different supply pathways. Cost and $30,000 $20,000 The cost of making a transition was roughly twice that of performance data about hydrogen production and delivery Case 1 (Hydrogen 2010 2015 2020 2025 2030 2035 2005 Success) and took several years longer technologies are discussed in Chapter 3. to complete. The committee makes several assumptions in designing Year Case 1a (Accelerated Hydrogen ) gave rise to a margin- the hydrogen infrastructure. ally faster transition, and the resulting reductions in oil use Figure6-6.eps and CO2 emissions were 25-33 percent greater than Case 1 1. Phased introduction. There is a phased introduction of (Hydrogen Success) by 2050. However, the estimated transi- hydrogen vehicles and stations in selected large cities, begin- tion cost for Case 1a was many times that for Case 1, because ning with cities such as Los Angeles and New York (with it assumed that more of the expensive early vehicles are interest and motivation to implement hydrogen) and moving pushed into the market in the early years of the transition. to other cities over time. This so-called lighthouse concept For these reasons the committee chose Case 1 (Hydrogen reduces infrastructure costs by concentrating development in Success) as the maximum practicable case as requested in its relatively few key areas termed “lighthouse cities.” A pos- statement of task. Cases 1a and 1b are not considered further sible schedule for phased introduction of hydrogen vehicles in this chapter. in various U.S. cities is shown in Figure 6.7. The list of 27 cities was chosen based on hydrogen scenario development work by DOE (Gronich, 2007; Melendez, 2006). hydrogen infrastructure requirements and costs 2. Station “coverage.” Initially, when hydrogen is intro- The UC Davis SSCHISM steady-state hydrogen supply duced in each lighthouse city, some minimum number of pathway model (Yang and Ogden, 2007b) is used to design hydrogen stations is needed to ensure adequate coverage and hydrogen infrastructure and estimate delivered hydrogen consumer convenience. This constraint is imposed to help costs for Case 1 (Hydrogen Success). Hydrogen equipment deal with the “chicken-and-egg” problem of assuring hydro- costs and performance are from the H2A model developed gen fuel availability to early non-fleet vehicle owners. This is by the Department of Energy (Paster, 2006). The H2A com- assumed to be 5 percent of existing gasoline stations in cities ponent-level data are combined into complete hydrogen sup- (Nicholas et al., 2004; Nicholas and Ogden, 2007). The per- ply pathways from hydrogen production through refueling centage of hydrogen stations and station capacity over time using the SSCHISM steady-state pathways model developed are shown in Figures 6.8 and 6.9. For the initial introduction at the University of California-Davis (Yang and Ogden, of hydrogen vehicles, it is assumed that 100 kg/d stations are

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 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS Figure6-7.eps FIGURE 6.7 DOE plan for introduction of light-duty hydrogen vehicles into 27 “lighthouse” cities (thousand vehicles per year introduced between 2012 and 2025). The overall build-up rate corresponds BITMAP total number of vehicles in 2025 is 10 million, and 2.5 million to Case 1. The vehicles are sold that year. SOURCE: Gronich (2007). available at 5 percent of gasoline stations for the first several added, and the fraction of gasoline stations offering hydro- years. (These very early stations might be supplied from the gen increases over time. To account for underutilization of existing industrial hydrogen system, using excess hydrogen hydrogen station equipment as demand grows, a relatively from refineries and other industrial or merchant sources.) low system capacity factor of 70 percent is assumed. This is followed by a brief period of building “medium- sized” 500 kg/d on-site steam methane reformers (SMRs) at The assumed capital costs of different hydrogen produc- 5 percent of gasoline stations. As demand grows, capacity tion systems are summarized in Table 6.4, based on H2A’s is added at each of these stations to make them 1,500 kg/d future (2015) technology assumptions (DOE, 2007). (See stations. Beyond about 2022, new 1,500 kg/d stations are also Chapter 3.) 1600 0.6 1400 0.5 Station capacity (kg/day) 1200 1000 0.4 Fraction 800 0.3 600 0.2 400 200 0.1 0 2000 2010 2020 2030 2040 2050 0.0 Year 2000 2010 2020 2030 2040 2050 Year Figure6-9.eps FIGURE 6.9 Capacity of new hydrogen stations by year, FIGURE 6.8 Fraction ofFigure6-8.eps gasoline stations offering hydrogen, 2000-2050. 2000-2050.

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80 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN TABLE 6.4 Assumed Capital Costs for Hydrogen 70,000 60,000 Production Systems Pipeline Stations 50,000 Pipeline Delivery Million $ Plant Size FUTURE TECH H2A 2015 40,000 Onsite SMR (tonne/d) Capital Cost (dollars/kg per day) 30,000 Biomass Plants 20,000 Central natural gas 50 621 Coal Plants 10,000 (SMR) 300 400 0 (production plant 400 375 2029 2023 2025 2027 2021 2019 2013 2015 2017 only) Year Central coal 250 1,275 (production plant 400 1,170 FIGURE 6.10 Early infrastructure capital costs for Case 1. color Figure6-10.eps only) 1,200 950 Central biomass 30 1,260 (production plant 155 860 450,000 only) 200 820 400,000 Pipeline Stations 350,000 300,000 Pipeline Delivery On-site SMR (station) 0.1 3,970 ($0.4 million per station) Million $ 250,000 0.5 1,811 ($0.9 million per station) Onsite SMR 200,000 1.5 1,452 ($2.2 million per station) Biomass Plants 150,000 100,000 Coal Plants On-site electrolysis 0.1 4,325 ($0.4 million per station) 50,000 (station) 0.5 2,050 ($1.0 million per station) 0 1.5 1,673 ($2.5 million per station) 36 46 26 21 31 41 16 20 20 20 20 20 20 20 Year FIGURE 6.11 Capital costsFigure6-11.eps color for hydrogen infrastructure. The SSCHISM infrastructure model compares the dif- ferent possible supply options in Table 6.2 for 73 different 10 U.S. cities, finding the lowest-cost supply in each city at a $ per gallon gasoline equivalent energy specified market penetration. The best choice depends on the H2: Case 1 8 (Hydrogen level of demand, the city size and demand density, and local 6 Success) energy and feedstock prices. For the first 5-10 years, on-site Gasoline AEO 2008 4 SMRs dominate the hydrogen supply. After that time, central high-price case 2 production plants begin to be built in large cities, with truck or pipeline delivery, although on-site SMRs are assumed to 0 persist in smaller cities. All coal hydrogen plants are assumed 2000 2010 2020 2030 2040 2050 to have carbon capture and sequestration (CCS). Biomass Year hydrogen plants are small in size (30-200 tonnes per day) to FIGURE 6.12 Estimated average cost of delivered hydrogen in the match the scale of regional biomass supply. This compares to United States and the assumed gasoline price. 250-1,200 tonnes per day for coal plants. The analysis uses color Figure6-12.eps a regional biomass supply curve (that specifies the amount of biomass available at a certain amount per tonne) (Perlack contributions from biomass hydrogen as well. However, it is et al., 2005) to reflect biomass feedstock cost increases as important to note that the delivered costs of hydrogen from demand grows. coal, biomass, and natural gas central plants are quite close Figure 6.10 shows the capital costs for infrastructure up (within $0.50/kg). Thus, the choice of a feedstock may be to 2030. On-site SMRs dominate, with central production determined by other factors, such as state policies favoring and pipeline delivery beginning after about 2027, when the renewables. The long-term capital cost for infrastructure is first central production systems using biomass and coal are roughly 25 percent on-site reformer stations, 25 percent cen- built. These are accompanied by pipeline delivery systems tral production plants (most hydrogen comes from coal, with and stations. Biomass plants appear slightly earlier than coal some from biomass), 25 percent delivery systems (pipelines hydrogen plants, and more of them are built because they predominate), and 25 percent refueling stations with truck or are smaller in size. Later, central production dominates in pipeline delivery. The U.S. average cost of delivered hydro- large cities, although on-site reformers persist in other areas gen is shown in Figure 6.12. (Figure 6.11). The total infrastructure capital cost is about $2,000 per In terms of the amount of hydrogen produced, coal- car served by the system. The total capital costs to build a based hydrogen is the dominant source, with significant

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8 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS TABLE 6.5 Type of Hydrogen Supply over Time Case 1 (Hydrogen Success) 2020 2035 2050 No. of cars served 1.8 million (0.7%) 61 million (18%) 219 million (60%) (percentage of total fleet) Infrastructure capital cost $2.6 billion $139 billion $415 billion Total no. of stations 2,112 (all on-site SMR) 56,000 (40% on-site SMR) 180,000 (44% on-site SMR) No. of central plants 0 113 (20 coal, 93 biomass) 210 (79 coal, 131 biomass) Pipeline length (miles) 0 39,000 80,000 Hydrogen demand 1,410 38,000 (22% NG, 42% 120,000 (31% NG, (tonnes per day) (100% NG) biomass, 36% coal 25% biomass, 44% coal with CCS) with CCS) NOTE: NG = natural gas. “steady-state” hydrogen infrastructure to serve the demands 80 in 2020, 2035, and 2050 are estimated in Table 6.5. Note TOTAL Diff (Gas 60 minus H2) that more than $400 billion is required to build the hydro- gen infrastructure to supply the fuel for the HFCV fleet in CMLTV Diff (Gas 40 2050. minus H2) Billion $ 20 CAP COST Diff Vehicles (Gas investment costs for hydrogen Fuel cell Vehicles to 0 minus H2) reach cost competitiveness FUEL COST Diff (Gas minus H2) -20 Examining the annual cash flows reveals the total invest- ment required for hydrogen HFCVs to reach “breakeven” -40 with gasoline ICEVs. These are shown in Figure 6.13: 2010 2015 2020 2025 2030 Year • The “CAP COST Diff” (dollars per year) is the differ- FIGURE 6.13 Cash flows for Case 1. ence in vehicle price for a gasoline vehicle versus a hydrogen Figure6-13.eps vehicle, summed over all the new HFCVs sold that year. This starts out negative (HFCVs cost a lot more than gasoline vehicles), but small (only a few HFCVs are sold). In the assumes that for a new fuel such as hydrogen with a small longer term, the annual cost difference continues to grow, HFCV fuel tank (approximately 5 to 8 gallons of gasoline as HFCVs are assumed to always cost more than gasoline equivalent), consumers would value fuel on a cost-per-mile cars. traveled basis (dollars per mile) rather than a cost-per-gallon- • “FUEL COST Diff” (dollars per year) is the annual equivalent basis, as they do now for gasoline. difference in fuel costs for HFCVs (counting all HFCVs cur- • “TOTAL Diff” (dollars per year) is the cash flow, rently in the fleet) compared to what would have been paid which equals the economy-wide cost per year of pursuing a to fuel comparable gasoline-fueled vehicles. Hydrogen soon fuel cell market introduction plan. The cash flow is defined becomes less costly as a fuel on a cents-per-mile basis, so this difference becomes positive around 2017.5 This analysis on many complex factors. Gasoline prices include federal, state, and lo- cal taxes. One could argue that hydrogen should be competed against the 5Hydrogen fuel becomes cost competitive with gasoline (on a cents-per- untaxed gasoline price. However, other alternative fuels such as ethanol are mile basis) in about 2017, when hydrogen costs are still fairly high, about untaxed to encourage their adoption, and the committee decided to give $5.60/kg. This is because the hydrogen vehicle is assumed to have a fuel hydrogen the same advantage. It should be noted that much of the revenue economy 2.0 times greater than the gasoline vehicle, and the gasoline price raised by gasoline taxes goes to highway maintenance and other necessary in the AEO high-oil-price case is $2.80 per gallon. This analysis compares functions that continue no matter what type of vehicles travel on them. As the cost of hydrogen with the price of gasoline. The committee decided discussed in Chapter 7, these revenues will have to be replaced from other this would be the most straightforward comparison because it would be sources if alternative fuels remain untaxed. On the other hand, the price of difficult to estimate a price for hydrogen without a model for all its uses in gasoline does not include the cost of externalities that hydrogen is intended the economy, and it is hard to estimate the cost of gasoline, which depends to address: CO2 emissions and oil imports.

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8 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN as the gasoline vehicle minus the annual cost of the hydro- TABLE 6.6 Transition Costs and Timing for Hydrogen gen vehicle. This starts out negative, but becomes positive Cases in 2023, when the cost of hydrogen vehicles becomes less Breakeven Year than that of a similar number of gasoline vehicles. While the (annual cash flow > 0) 2023 HFCVs first cost remains higher than for the gasoline car, Cumulative life-cycle cost difference $22 billion the net fuel cost savings make the annual cash flow positive (between HFCV and gasoline reference at the breakeven year. car) to breakeven year • “CMLTV Diff” (dollars) is the cumulative cost differ- Cumulative vehicles first-cost $40 billion ence, the sum of the cost difference over time (starting in difference (between HFCV and (~$3.3 billion/yr) 2012), providing a yearly tally of the total funds that would gasoline reference car) to breakeven year have to be invested to make HFCVs competitive. At first, there is a negative cash flow (early HFCVs cost more than Number of HFCVs at breakeven year 5.6 (1.9% of fleet) gasoline cars), but eventually as HFCV and hydrogen fuel (millions) costs come down, the negative cash flow “bottoms out” in Hydrogen cost at breakeven year $3.3/kg 2023 at a minimum of about $22 billion, when about 5.6 mil- Hydrogen demand; number of 4,200 tonnes/d; 3,600 lion fuel cell vehicles have been produced. This minimum is hydrogen stations at LCC breakeven stations the “buydown” investment that must be supplied to bring the year HFCV to cost competitiveness. Total cost to build infrastructure for $8.2 billion demand at LCC breakeven year Most of the negative cash flow is due to the high price of Year when hydrogen fuel cost per 2016 the first few million fuel cell vehicles. This is not surpris- kilometer = gasoline price per ing, since, initially, fuel cell vehicles cost a lot more than kilometer gasoline vehicles (see Figure 6.6). The subsidy that might Hydrogen cost ($/kg) 5.20 be needed by automakers or buyers is the sum of the dif- ference in costs between HFCVs and gasoline cars, each Gasoline price ($/gal) 2.70 year between vehicle introduction in 2012 and life-cycle cost (LCC) breakeven in 2023. This cumulative difference Total cost to build infrastructure to $0.5 billion (1,000 small in vehicle first cost for HFCVs (as compared to a reference meet demand in 2023 (LCC on-site SMR stations) breakeven year) gasoline vehicle) is about $40 billion (averaged over the 2012-2023 buydown period, this is about $7,000 per car, or an average of $3.3 billion per year for 12 years). Transition dates and costs are summarized in Table 6.6, relative to a resUlTs: comParisoN oF GreeNhoUse reference gasoline vehicle. Gas emissioNs aNd oil disPlacemeNT For The buydown cost is quite sensitive to assumptions sceNarios for key factors. For example, if fuel cell vehicles could be introduced at their “learned-out cost” (e.g., the cost of assumed Greenhouse Gas emissions for Fuels HFCVs once they have become technically mature and are manufactured at large scale), buydown cost requirements Until 2020, all hydrogen comes from on-site SMRs with for vehicles would be greatly reduced, and fuel cell vehicles a CO2 release of 100 g CO2 equivalent per megajoule of would become competitive almost immediately. In this case, fuel. After that time, low-carbon sources such as biomass the primary transition cost would be building a hydrogen hydrogen and hydrogen from coal with carbon capture infrastructure to the point at which hydrogen is competitive and storage are phased in. By 2050, roughly 31 percent of as a fuel (fuel cost per kilometer), on the order of a billion hydrogen is produced via on-site SMRs, the remainder via dollars. Note that this would happen much sooner than the low-carbon sources (44 percent coal with CCS, 25 percent vehicles reaching cash flow breakeven (see bottom row in biomass H2). Thus, the overall emissions for hydrogen sup- Table 6.6). Box 6.1 explores the sensitivity of the results to ply in 2050 are 37 g CO2/MJ fuel, based on the CO2 values assumptions on HFCV fuel economy and incremental costs, given in Table 6.7, which shows the assumptions regarding and the cost of hydrogen and gasoline. the well-to-wheels emissions associated with different fuel supply pathways. In all cases, the carbon emissions from the hydrogen supply are assumed to follow the curve shown in Figure 6.14, where CO2 emissions are shown as declining linearly between 2020 and 2050. The average CO2 emissions might fall faster than this, because most new capacity after

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8 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS TABLE 6.7 Assumed Greenhouse Gas Emissions per Unit 120 of Fuel Consumed 100 g CO2 eq per MJ fuel Fuel Greenhouse Gas Content of Fuels (g CO2 equivalent/MJ fuel used 80 LHV basis) 60 Conventional gasoline 90 (AEO 2007 projections to 2030 show this staying 40 approximately constant) Hydrogen from on-site 100 (TIAX, 2007) 20 reformation Hydrogen from coal with CCS, 16 (92% CO2 capture rate, 0 pipeline delivery assuming U.S. electricity mix) 2000 2010 2020 2030 2040 2050 0 (100% CO2 capture rate, Year assuming zero-carbon FIGURE 6.14 Greenhouse gas emissions from hydrogen supply electricity is used for CO2 compression) (adapted over time. Figure6-14.eps from Ruether et al., 2005). Coal mining, transport, and plant and mine construction emissions are estimated to be 200,000 Million gallons per year about 3.8 g CO2 eq/MJ H2, but this is counterbalanced by 150,000 GHG savings of about 4.3 g Case 1 (H2 CO2 eq/MJ, due to exported Success) 100,000 electricity from the plant) Reference Hydrogen from biomass, 10 (TIAX, 2007) 50,000 pipeline delivery Hydrogen from electrolysis 0 0 using zero-carbon 2000 2010 2020 2030 2040 2050 electricity (wind, hydro, solar) Year Ethanol from corn 70 (22% reduction relative to FIGURE 6.15 Case 1 gasoline consumption relative to the refer- gasoline) ence case. Ethanol from cellulose 13 (85% reduction relative to Figure6-15.eps gasoline) SOURCES: Ruether et al. (2005); TIAX (2007). 1800 Million tonnes CO2 eq/yr 1600 1400 1200 Case 1 (H2 2025 is likely to be very low carbon in these scenarios (70 1000 Success) percent biomass hydrogen or coal hydrogen with CCS). 800 Reference 600 case 1 (hydrogen success) 400 200 Oil Displacement 0 2000 2010 2020 2030 2040 2050 Figure 6.15 estimates gasoline consumption for the Year Hydrogen Success case and the reference case. Oil displace- ment is about 0.8 percent in 2020, rising to 24 percent in 2035 FIGURE 6.16 Case 1 greenhouse gas emissions relative to the and 69 percent in 2050. Although it takes several decades for reference case. hydrogen’s impact to be seen, beyond 2025 it enables grow- Figure6-16.eps ing reductions in both greenhouse gas emissions per year and annual oil use. Hydrogen may be important to achieve long-term stabilization goals requiring deep cuts in carbon Greenhouse Gas Reductions or oil use. Figures 6.15 and 6.16 show a dip in the reference Figure 6.16 shows the committee’s estimate of the reduc- case after about 2020. This occurs even though the increase tions in greenhouse gas emissions for Case 1 (Hydrogen in fuel economy of new cars levels off because the entire on- Success) relative to a reference case, where no hydrogen road fleet fuel economy increases as new efficient vehicles technologies are introduced. Greenhouse gas emissions per replace older vehicles.

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8 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN BoX 6.1 sensitivity of Breakeven analysis results to changes in assumptions The results of an analysis of the costs and timing of a hydrogen transition depend on many assumptions and inputs and are sensitive to changes in four important input parameters: 1. The fuel economy of an HFCV compared to a reference gasoline vehicle; 2. The incremental cost of an H2FCV compared to a gasoline reference vehicle; 3. The cost of hydrogen; and 4. The cost of gasoline (dollars per gallon). The values of these parameters for Case 1 (Hydrogen Success) are shown in Table 6.1.1. Also shown are potential high and low values for each parameter. Each parameter is varied over this range. Three key metrics that describe a hydrogen transition are: 1. The “breakeven year”; 2. The “breakeven cost” (e.g., cumulative cash flow to get to the breakeven year); and 3. The total capital cost (the incremental cost for HFCVs + the infrastructure cost) to get to the breakeven year. TABLE 6.1.1 Range Over Which Parameter Values Can Vary for Case 1 Parameter Low Value Case 1 Value High Value Fuel economy of HFCV versus fuel 1.3 2 3 economy of efficient gasoline car Incremental cost of HFCV compared 1,713 3,600 6,800 to reference gasoline vehicle (FC system = $50/kW; (FC system = $50/kW; (FC system = $62/kW; H2 H2 storage = $2/kWh) H2 storage = $10/kWh) storage = $18/kWh) Incremental cost of H2 compared to −$2/kg 0 $2/kg Case 1 long-term cost Price of oil 0.5 × high-price case (oil at Oil price from AEO 2008 high- 1.3 × high price case (oil at $40-$60/bbl in 2012-2030) price case (oil at $80-$120/bbl $105-$160/bbl in 2030) in transition period 2012-2030) NOTE: bbl = barrel; FC = fuel cell.

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8 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS 2040 Breakeven year 2035 Fuel Economy Ratio (FCV/Gasoline ICEV) 2030 FCV Price Increment $ The value for each of these three metrics is shown as a func- 2025 tion of the variables in a series of three “spider plots” (Figures H2 Cost Increment (from Case 1) $/kg 2020 6.1.1-6.1.3). In each plot, the x-axis is the ratio of the variable Oil Price Multiplier (X 0 0.5 1 1.5 2 to its Case 1 value (shown in Table 6.1.1.). (The normal Case 1 AEO hp) Variable/Base value input is represented by a value of “1” on the x-axis. So, an HFCV FIGURE 6.1.1 Sensitivity of breakeven year to changes in HCFV fuel incremental cost of $3,600 corresponds to an x-value of 1, while economy, HFCV price, H2 cost, and gasoline price. an HFCV incremental cost of $6,800 corresponds to an x-value of color FigureBox6.1-1.eps 6,800/3,600 = 1.88.) When the input parameter is varied from its low to its high values, the value of x changes from 0.5 to 2. The metric varies as the input changes. This shows the sensitivity of the results to changes in the input variables. 100 90 Fuel Economy Ratio As expected, the breakeven year is delayed and buydown costs (FCV/Gasoline ICEV) 80 are higher if the HFCV price is higher, the HFCV is less efficient, 70 FCV Price Increment Billion $ or hydrogen costs more than in Case 1. Breakeven occurs faster 60 $ 50 H2 Cost Increment and the buydown cost is less for higher oil prices. 40 (from Case 1) $/kg For example, if hydrogen costs $1/kg more than expected, 30 Oil Price Multiplier 20 there is relatively little impact on the breakeven year or the transi- (X AEO hp) 10 tion cost. However, if the cost of hydrogen is $2/kg higher than 0 expected, this delays breakeven by 12 years (from 2023 to 2035) 0 0.5 1 1.5 2 Input value/Base value and raises the breakeven cost by almost a factor of three (from about $23 billion to $61 billion). If the oil price is 1.3 times the color FigureBox6.1-2.eps AEO’s projected high-price case (e.g., about $100 to $160 per FIGURE 6.1.2 Sensitivity of buydown cost (billion dollars) to changes in barrel of oil in the transition period between 2012-2030), the HFCV fuel economy, HFCV price, H2 cost, and gasoline price. breakeven year is accelerated slightly. However, if oil prices drop to 70 percent of the AEO projections (e.g., about $55 to $85 per barrel of oil during the transition period 2012-2030), breakeven is Fuel Economy Ratio delayed 5 years (from 2023 to 2028) and the buydown cost rises (FCV/Gasoline 600 from $23 billion to $31 billion. If oil prices drop to 50 percent of ICEV) FCV Price 500 the AEO high-price case ($40 to $60 per barrel during the transi- Increment $ 400 tion), breakeven is delayed further to 2035, and the buydown cost Billion $ almost triples to $61 billion. 300 H2 Cost Increment (from 200 Case 1) $/kg 100 Oil Price 0 Multiplier (X 0 0.5 1 1.5 2 AEO hp) Variable/Base Value FIGURE 6.1.3 Sensitivity ofFigureBox6.1-3.eps color capital investment to breakeven year (incre- mental price of HFCVs + H2 infrastructure capital, billion dollars).

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8 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN year are reduced by about 0.7 percent in 2020, 19 percent 70 in 2035, and 60 percent in 2050 compared to the reference Fuel economy (mpg) 60 case. 50 40 Gasoline ICEV Gasoline HEV case 2 (iceV efficiency) 30 20 Case 2 is an “evolutionary,” not revolutionary, scenario. 10 The committee assumes that currently available improve- 0 ments in gasoline internal combustion engine technology 2000 2010 2020 2030 2040 2050 are used to improve fuel economy (rather than power and Year acceleration). A range of more efficient advanced gasoline technolo- FIGURE 6.18 Case 2 assumed on-road fuel economy for new Figure6-18.eps gies could be implemented in 2010-2035 as described in gasoline ICEVs and gasoline hybrid ICEVs over time. Chapter 4. In this scenario, a new “high-fuel-economy” gasoline vehicle is introduced, as well as a hybrid gasoline vehicle, and these capture growing market share over time. trains could offer an additional 15 percent reduction in fuel By 2035 (2050), 42 percent (85 percent) of new LDVs and consumption and CO2 emissions over advanced conventional 30 percent (60 percent) of the fleet are gasoline hybrids, and spark ignition power trains and have cost advantages over the remaining non-hybrid cars have high fuel economy. This hybrid electric vehicles (see, for example, Adrian, 2004). In is shown in Figure 6.17. a high-fuel-cost environment, they could become a growing In 2010, the new gasoline vehicle is assumed to have an fraction of LDV sales with the some shifts in government on-road fuel economy of 22.2 mpg, the hybrid 31.9 mpg. positions on diesels and a positive public relations program. (These values are selected to match the reference case up to Thus, to the extent that diesels can penetrate the market, this 2010.) The fuel economy of each vehicle is then assumed to scenario may understate potential fuel savings. improve as follows and discussed in Chapter 4: The same vehicle stock model used in the reference case keeps track of the vehicle numbers and vintages of advanced • 2.6 percent per year from 2010 to 2025, gasoline cars and gasoline hybrids on the road in any year. • 1.7 percent per year from 2026 to 2035, and This allows calculation of oil consumption and greenhouse • 0.5 percent per year from 2035 to 2050. gas emissions for each year. The on-road new car fuel economy over time is plotted in Figure 6.18. Note that this is similar to the reference case Oil Displacement in Figure 6.4 up to about 2020. Beyond this, Case 2 is sig- Gasoline consumption for the case above is estimated in nificantly more efficient; by 2050, gasoline ICEV and hybrid Figure 6.19. Improving fuel economy is a very effective way cars are about 35 percent more efficient than in the reference to cut gasoline use. Gasoline consumption in 2020 is only case, which incorporates the new CAFE standards. slightly reduced relative to the reference case, which includes The committee did not project increased market share for rapidly improving fuel economy, but in 2035 it is down by diesel engines in this scenario because of the uncertainty over 35 billion gallons per year (25 percent), and in 2050, by 64 the costs of meeting future tailpipe emission specifications billion gallons per year (40 percent). and consumer acceptance, considering the poor history of diesels in U.S. automobiles. However, advanced diesel power Greenhouse Gas Reductions 400 Greenhouse gas emissions show a similar trend (Figure 350 Million vehicles 6.20). Fuel economy improvements can yield increasing 300 Gasoline ICEV 250 reductions in greenhouse gases. Greenhouse gas emissions 200 Gasoline HEV are reduced by about 24 million tonnes of CO2 equivalent per 150 TOTAL year (1.7 percent) by 2020, 385 million tonnes (25 percent) 100 by 2035, and 700 million tonnes (41 percent) by 2050. 50 0 Based on projected gasoline prices and cost estimates 2000 2010 2020 2030 2040 2050 for improved fuel economy, it appears that gasoline hybrids Year and advanced gasoline vehicles would pay for themselves on a life-cycle cost basis, so no external subsidy should FIGURE 6.17 Case 2 assumed market penetration for gasoline be needed. A simple calculation shows that increasing fuel ICEVs and advanced gasoline HEVs. Figure6-17.eps economy from 30 to 45 mpg in a car that travels 15,000

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8 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS miles a year saves 167 gallons of gasoline per year. If a car 180,000 Million gallons per year 160,000 is kept 10 years and gasoline costs $2.5 per gallon, the pres- 140,000 ent value of fuel savings amounts to $2,565 (assuming a 10 Case 2 (ICEV 120,000 percent discount rate). This would be enough to pay for the Efficiency) 100,000 difference in first cost between a conventional gasoline car 80,000 Reference 60,000 and a hybrid, which is estimated to be $1,800-$2,500 per car 40,000 (Kromer and Heywood, 2007). 20,000 0 1990 2010 2030 2050 case 3: Biofuels Year Case 3, Biofuels, considers an emphasis on biofuels in FIGURE 6.19 Gasoline consumption for Case 2 and for the refer- the transportation sector. Assumptions about the introduction Figure6-19.eps ence case. of biofuels are summarized in Table 6.8. Annual production levels for various biofuels are plotted in Figure 6.21. The 1800 detailed assumptions are discussed in Chapter 4. For refer- Million tonnes CO2 eq/yr 1600 ence, the maximum practicable case, in the committee’s 1400 judgment, is 700 million dry tons of sustainable biomass 1200 Case 2 (ICEV available in 2050, with all of the biomass used for cellulosic 1000 Efficiency) ethanol production at 90 gallons per dry ton. This would total 800 Reference 63 billion gallons of ethanol per year in 2050, the amount 600 assumed in Case 3. 400 200 The AEO 2007 reference case includes about 12 billion 0 gallons of corn ethanol by 2030 plus an additional 3 billion 2000 2010 2020 2030 2040 2050 gallons of cellulosic ethanol. The committee extended this to Year assume that in the reference case, cellulosic ethanol produc- tion reaches 9 billion gallons per year by 2050. The assumed FIGURE 6.20 Greenhouse gas emissions for Case 2 and for the biofuels use in the reference case is shown in Figure 6.5. Figure6-20.eps reference case. TABLE 6.8 Assumed Biofuel Use in Case 3 Corn Ethanol Cellulosic Ethanol Biobutanol Biodiesel F-T Diesel via Biomass Gasification Production Timing of introduction similar to that (billion gallons) for biomass H2, toward end of scenario time frame • 2002 • 2006 2.5 • 2008 6 0.25 • 2010 8 1 • 2015 10 6 0.6 (2012) • 2020 12 (max = 30% of 16 0.1 expanded corn crop) • 2025 28 0.6 1.5 (max = 30% of soy • 2030 36 2.6 crop, limited by land) • 2035 12 44 4.0 • 2050 63 CO2 reduction 22% relative to 85% relative to 80% relative to regular (energy equivalent gasoline gasoline diesel basis) Oil reduction 1 gallon gasoline 1 gallon gasoline 1 gallon biodiesel (energy equivalent equivalent ethanol equivalent ethanol replaces 0.95 gallon oil basis)a replaces 0.96 gallon replaces 0.93 gallon oil oil aGasoline = 119,000 Btu/gal, ethanol = 80,000 Btu/gal, and biodiesel is equivalent to regular diesel.

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88 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN 70 45 Billion gallons per year 40 Billion gallons per year 60 35 50 Corn Ethanol 30 Cellulosic EtOH 40 Cellulosic EtOH 25 Biobutanol Biobutanol 30 20 Biodiesel Biodiesel 20 15 TOTAL 10 10 5 0 0 2000 2010 2020 2030 2040 2050 2000 2010 2020 2030 2040 2050 Year Year FIGURE 6.21 Annual production of biofuels assumed for Case 3. FIGURE 6.23 Case 3: Oil displacement relative to the reference color Figure6-21.eps color Figure6-23.eps case. The reference case corresponds to about 10 percent etha- 450 nol by volume in gasoline by 2050. In Case 3 (Biofuels), this Million tonnes CO2 eq/yr 400 Cellulosic EtOH is expanded to include an additional 54 billion gallons of 350 high biofuels per year (beyond the reference case). This is roughly 300 Biobutanol four times the biofuel use in the reference case or about 40 250 percent ethanol in gasoline plus some other advanced bio- 200 Biodiesel fuels. It is important to note that the greenhouse gas and 150 oil reductions shown for Case 3 are relative to a reference TOTAL high 100 case that already includes biofuel use up to 10 percent of 50 gasoline by volume. 0 In the Biofuels case, the assumed corn ethanol use is the 2000 2010 2020 2030 2040 2050 same as in the reference case. The difference is that more Year cellulosic and other advanced biofuels are produced. The FIGURE 6.24 Case 3: Greenhouse gas emission reductions relative additional biofuels production assumed in the Biofuels case to the reference case. (compared to the reference case) is shown in Figure 6.22. color Figure6-24.eps Gasoline displacement for Case 3 is shown in Figure 6.23. The total is about 12 billion gallons per year by 2020 and 39 billion gallons per year in 2050. comparison of scenarios Greenhouse gas emissions reductions are given in Figure The estimated savings in gasoline use and greenhouse 6.24 for the Biofuels case. The total reduction in greenhouse gas emissions for each case are plotted in Figures 6.25 and gas emissions is about 8 percent from the reference case by 6.26. In the near to mid term, improving the fuel economy 2020, rising to 23 percent by 2050. The committee has not of gasoline vehicles will be the most effective option for estimated the costs of building biofuel production plants or reducing oil use and greenhouse gas emissions. This is changes in the fuel distribution infrastructure that might be already incorporated in the reference case up to 2020, but needed. continued improvements thereafter could match the savings from hydrogen until about 2035. Biofuels could begin to make a difference sooner than hydrogen, which takes more time to implement, assuming cellulosic ethanol comes online in 2010. After about 2032, however, Case 1 (Hydrogen Suc- 60 Additional Corn cess) would lead to greater greenhouse gas reductions per Billion gallons Ethanol per year 40 year than Case 3 (Biofuels). By 2040, the Hydrogen Success Additional Cellulosic EtOH scenario offers about twice the greenhouse gas reduction and 20 Biobutanol oil savings per year as the Biofuels scenario, and by 2050, 0 almost three times the reduction. This clearly illustrates the 2000 2010 2020 2030 2040 2050 Biodiesel time frames for different technologies and the total contri- Year butions they might make by 2020 and beyond. Although FIGURE 6.22 Case 3: Added biofuel production relative to the efficiency and biofuels could contribute sooner, hydrogen reference case. would surpass the annual savings achievable with either after

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8 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS combined case than for HFCVs alone. By 2020, efficiency 180,000 Million gallons per year Case 1 (H2 160,000 reduces greenhouse gas emissions by about 1.8 percent rela- Success) 140,000 tive to the base case. Beyond 2030, HFCVs lead to deeper 120,000 Case 2 (ICEV Eff) cuts in emissions than would be possible with efficiency 100,000 alone. 80,000 Case 3 (Biofuels) 60,000 40,000 Reference case 3 + case 2: Biofuels + iceV efficiency 20,000 0 Combining higher gasoline vehicle efficiency with biofu- 2000 2010 2020 2030 2040 2050 els yields much greater reductions in oil use and greenhouse Year gas emissions than are possible with biofuels alone. This is shown in Figures 6.29 and 6.30, which combine Cases 2 FIGURE 6.25 Oil consumption for Cases 1-3 compared. and 3. By 2020, biofuel use alone could reduce annual oil use by about 8 percent, with efficiency bringing the total color Figure6-25.eps to 10 percent. In the longer term, the effect of efficiency 2000 improvements dominates, with biofuels saving 23 percent of gasoline use or greenhouse gas emissions in 2050 and Million tonnes 1500 Case 1 (H2 Success) CO2 eq/yr efficiency an additional 41 percent. This strategy “stretches” Case 2 (ICEV Eff) 1000 limited biomass resources to fuel more vehicle miles traveled Case 3 (Biofuels) per acre of land. Reference 500 0 2000 2010 2020 2030 2040 2050 Year FIGURE 6.26 Greenhouse gas emissions for Cases 1-3 compared. 180,000 Million gallons per year 160,000 color Figure6-26.eps Case 1 + Case 140,000 2 (H2 Success 120,000 and ICEV Efficiency) 100,000 Reference 80,000 60,000 2035. This result highlights the long time constants inherent 40,000 in changing the energy system, as well as the need to develop 20,000 long-term, very low carbon options. 0 2000 2010 2020 2030 2040 2050 comBiNed aPProaches To redUciNG Year GreeNhoUse Gas emissioNs FIGURE 6.27 Oil use for Cases 1 and 2 combined. aNd oil Use Figure6-27.eps The previous section looked at the potential impact of implementing one technological measure at a time. In the 1800 future, reducing oil use and greenhouse gas emissions prob- Million tonnes CO2 eq/yr 1600 ably will be increasingly important, and it is likely that a 1400 Case 1 + Case 2 combination of approaches would be implemented. However 1200 (H2 Success and the reductions for each approach cannot simply be added 1000 ICEV Efficiency) because they affect each other. This section considers several 800 Reference 600 combinations. 400 200 case 1 + case 2: hFcVs + iceV efficiency 0 2000 2010 2020 2030 2040 2050 This case combines higher gasoline vehicle efficiency Year with introduction of hydrogen fuel cell vehicles (Case 1 and Case 2). The results are shown in Figures 6.27 and 6.28. FIGURE 6.28 Greenhouse gas emissions with HFCVs for Cases Comparing Figure 6.27 and 6.25, gasoline consumption Figure6-28.eps 1 and 2 combined. in 2035 is about 18 billion gallons per year lower for the

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0 TRANSITIONS TO ALTERNATIVE TRANSPORTATION TECHNOLOGIES—A FOCUS ON HyDROGEN 400 Case 2 (ICEV 200,000 Million gallons per year Efficiency) Million vehicles 300 Gasoline ICEV 150,000 Gasoline HEV Case 3 (Biofuels) 200 Hydrogen FCV 100,000 100 TOTAL Case 3 + Case 2 50,000 0 (Biofuels + ICEV 2000 2010 2020 2030 2040 2050 Efficiency) 0 Reference Year 2000 2010 2020 2030 2040 2050 Year FIGURE 6.31 Assumed number of vehicles in the fleet for Case 4. FIGURE 6.29 Oil use for Cases 2 and 3 combined. color Figure6-31.eps color Figure6-29.eps 180,000 Million gallons per year 160,000 1800 Case 2 (ICEV 140,000 1600 Million tonnes CO2 /yr Efficiency) 120,000 1400 Case 4 (Portfolio) 100,000 1200 Case 3 (Biofuels) 80,000 Reference 1000 60,000 800 40,000 600 Case 3 + Case 2 20,000 400 0 (Biofuels + ICEV Efficiency) 200 2000 2010 2020 2030 2040 2050 0 Reference Year 2000 2010 2020 2030 2040 2050 Year FIGURE 6.32 Oil use in million gallons per year for Case 4. Figure6-32.eps FIGURE 6.30 Greenhouse gas emission reductions for Cases 2 and 3 combined. color Figure6-30.eps case 4 (Portfolio): implement efficient iceVs plus TABLE 6.9 Gasoline Displacement for Cases 1-4 Biofuels and hydrogen FcVs Compared to Reference Case Case 4 combines all three of the major options discussed Billion Gallons Gasoline Saved per Year (% Saved) above. Figure 6.31 shows the assumed numbers of vehicles Case 2020 2035 2050 in the fleet over time. Note that the number of hydrogen vehicles is the same as in Case 1 (Hydrogen Success) and Case 1 (Hydrogen 1.0 (0.8%) 34 (24%) 109 (69%) the number of gasoline ICEVs is the same as in Case 2 Success) (ICEV Efficiency). The number of advanced gasoline ICEVs Case 2 (ICEV 2.2 (1.7%) 35 (25%) 64 (41%) (hybrids) increases, but eventually loses market share to Efficiency) HFCVs. Figure 6.32 shows the reduction in petroleum consump- HFCVs + ICEV 3.0 (2.2%) 55 (39%) 125 (80%) tion over time for Case 4. Gasoline use is virtually eliminated Efficiency in the light duty vehicle fleet by 2050. Table 6.9 shows the Case 3 (Biofuels) 12 (9%) 28 (20%) 39 (25%) reduction in gasoline use for the four cases relative to the reference case. Case 3 + Case 2 14 (11%) 64 (45%) 103 (66%) Table 6.10 lists the emissions reductions relative to the Biofuels + ICEV reference case for the four cases. Emissions of greenhouse Efficiency gas over time are shown in Figure 6.33. The cumulative Case 4: 15 (11%) 83 (59%) 157 (100%) impact of reductions is shown in Figure 6.34. With a com- ICEV Efficiency bined approach including efficiency, biofuels, and hydrogen (Case 2) + Biofuels fuel cells, it is possible to reduce CO2 emissions by about 90 (Case 3) + percent and gasoline use by 99 percent by 2050. Hydrogen (Case 1)

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 HyDROGEN AND ALTERNATIVE TECHNOLOGIES FOR REDUCTION OF U.S. OIL USE AND CO EMISSIONS coNclUsioNs TABLE 6.10 Greenhouse Gas Emission Reductions for Cases 1-4 Compared to Reference Case CONCLUSION: In the judgment of the committee, the Million Tonnes CO2 Equivalent Avoided (% Avoided) maximum practicable number of HFCVs that could be on the road by 2020 is around 2 million. Subsequently, this Case 2020 2035 2050 number could grow rapidly to as many as 60 million by Case 1 10 (0.7%) 295 (19%) 1,026 (60%) 2035 and more than 200 million by midcentury, but such (Hydrogen rapid and widespread deployment will require continued Success) technical success, cost reductions from volume produc- Case 2 (ICEV 24 (1.7%) 385 (25%) 700 (41%) tion, and government policies to sustain the introduction Efficiency) of HFCVs into the market during the transition period needed for technical progress. HFCVs 26 (1.8%) 475 (31%) 1,123 (66%) + ICEV Efficiency CONCLUSION: While it will take several decades for HFCVs to have major impact, under the maximum prac- Case 3 118 (8%) 281 (18%) 386 (23%) ticable scenario fuel cell vehicles would lead to significant (Biofuels) reductions in oil consumption and also significant reduc- tions in CO2 emissions if national policies are enacted to Case 3 + 143 (10%) 666 (44%) 1,086 (64%) Case 2 restrict CO2 emissions from central hydrogen production Biofuels plants. + ICEV Efficiency CONCLUSION: The unit costs of fuel cell vehicles and Case 4: 130 (9%) 747 (49%) 1,505 (88%) hydrogen in the Hydrogen Success scenario—the maxi- Hydrogen mum practicable case—decline rapidly with increasing (Case 1) + vehicle production, and by 2023 the cost premium for ICEV Efficiency HFCVs relative to conventional gasoline vehicles is pro- (Case 2) jected to be fully offset by the savings in fuel cost over the + Biofuels life of the vehicle relative to a reference case based on the (Case 3) EIA high-oil-price scenario. At that point, according to the committee’s analysis, HFCVs become economically 1800 competitive in the marketplace. 1600 Million tonnes CO2 eq/yr 1400 Fully implementing the maximum practicable hydrogen 1200 case by 2050 would require construction of approximately 1000 Case 4 (Portfolio) 80,000 on-site distributed natural gas reforming units, 80 800 Reference coal gasification plants of 500 MW (electrical equivalent) 600 with CCS, 130 biomass gasification plants (each 100 MW 400 equivalent) with associated biomass growth and collection 200 farms, and roughly 80,000 miles of pipelines for hydrogen 0 supply and CCS. The committee estimates that more than 2000 2010 2020 2030 2040 2050 $400 billion would be required to fully build out hydrogen Year supply to fuel the HFCVs by 2050. FIGURE 6.33 Greenhouse gas emissions for Case 4 (combination The committee’s analysis indicates that at least two alter- Figure6-33.eps of HFCVs, efficiency, and biofuels). natives to HFCVs—advanced conventional vehicles and bio- fuels—have the potential to provide significant reductions in 30,000 Million tonnes CO2 eq projected oil imports and CO2 emissions. However, the rate Case 2 (ICEV 25,000 of growth of benefits from each of these two measures slows Efficiency) 20,000 after two or three decades, toward the end of the committee’s 15,000 Case 3 + Case 2 analysis period, while the growth rate of projected benefits 10,000 (Biofuels + ICEV from fuel cell vehicles is still increasing. The deepest cuts in Efficiency) 5,000 oil use and CO2 emissions after about 2040 would be from Case 4 (Portfolio) 0 hydrogen. 2000 2010 2020 2030 2040 2050 Over the next 20 years, the greatest impact on U.S. oil Year and CO2 reductions would result from implementing existing FIGURE 6.34 Cumulative reduction of greenhouse gas emissions Figure6-34.eps for Case 2, Case 3 plus Case 2, and Case 4.

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