Future Truck Position Paper:

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1 Issued: October 2017 Future Truck Position Paper: Hydrogen Fuel Cells for Heavy Trucks Developed by the Technology & Maintenance Council s (TMC) Future Alternate Propulsion System Task Force ABSTRACT The application of hydrogen fuel cell technology to commercial trucks has received a great deal of attention lately, especially following the announcement of at least one manufacturer s plans to introduce a hydrogen-hybrid electric model for purchase by the year 2020 and a second OEM s planned test at the Port of Los Angeles. As might be expected, this interest has prompted many questions by both fleet and supplier professionals. TMC's Future Truck Committee charged its Future Alternate Propulsion System Task Force to explore the issue and this paper represents its findings as to whether the technology is ready for commercial use, using a pass/fail scale. INTRODUCTION The application of hydrogen fuel cell technology to commercial trucks has received a great deal of attention lately, especially following the announcement of at least one manufacturer s plans to introduce a hydrogen-hybrid electric model for purchase by the year 2020 and a second OEM s planned test at the Port of Los Angeles [1a]. There are surely others either recently announced or in the planning stages. That announcement came with the expectation that there will be more than 50 operational hydrogen fueling stations throughout the U.S. by 2020, with the first groundbreaking in (Within a decade, more than 350 stations are planned as well). Currently, there are 33 hydrogen stations, excluding private stations in the U.S. [1b]. As might be expected, the new interest in hydrogen fuel cell technology has prompted many questions by both fleet and supplier professionals. TMC's Future Truck Committee charged its Future Alternate Propulsion System Task Force to explore the issue and this paper represents its findings. This paper will pose a series of questions, provide answers to those questions, and pass judgement as to whether the technology is ready for commercial adoption, using a pass/fail scale. Technology & Maintenance Council (TMC) 950 N. Glebe Road Arlington, VA Ph: (703) FAX: (703) tmc@trucking.org TMC Future Truck Committee Position Paper (2017-2) 1

2 QUESTIONS During its research, the Task Force identified the following questions: Regarding energy release rate, how much damage could the hydrogen in a truck fuel cell (tank) cause when the tank is pierced in a full condition? How does this compare to propane, compressed natural gas and gasoline? Regarding evacuation radius, what is the damage radius when a tanker of hydrogen is ruptured? How does this compare to gasoline? Regarding energy equivalence, how does hydrogen compare to diesel assuming diesel is $2.00 per gallon? Regarding environmental issues, how much hydrocarbon energy is consumed in the production of hydrogen fuel and how does this compare to diesel? - Handling: What would happen if a first responder used the jaws of life to cut open a wreck and, in the process, cut a line that released hydrogen? Do first responders need special training? - Fueling: Will a driver need special gloves to fill the tank? Regarding fill time, how long will it take to fill a hydrogen tank on a truck from empty? From one-quarter full? Regarding efficiency, how efficient is hydrogen fuel cell technology? Regarding durability, will a hydrogen fuel engine last as long as a diesel? As comparison, gasoline (internal combustion), propane and CNG engines last about half as long. Regarding reliability, how reliable are hydrogen fuel cells? Regarding training, what driver and technician training guidelines exist? Are the training needs comparable to diesel, CNG or propane? FINDINGS Q: How efficient is hydrogen fuel cell technology? The energy efficiency of a system or device that converts energy is measured by the ratio of the amount of useful energy put out by the system ( output energy ) to the total amount of energy that is put in ( input energy ) or by useful output energy as a percentage of the total input energy. In the case of fuel cells, useful output energy is measured by the amount of electrical energy produced by the system. Input energy is the energy stored in the fuel. According to the U.S. Department of Energy, fuel cells are generally between percent energy efficient. [2] This is higher than some other systems for energy generation. For example, the typical internal combustion engine of a car is about 25 percent energy efficient according to one U.S. government source [3] while another U.S. government source indicates a thermal efficiency of 30 percent [4]. For comparison, diesel engines are over 45 percent efficient, with further advances possible, to percent [5] and yet another indicates a potential diesel efficiency of 56 percent. [6] In combined heat and power (CHP) hydrogen fuel cell systems, the heat produced by the fuel cell is captured and put to use, increasing the efficiency of the system to up to percent.[7] The theoretical maximum efficiency of any type of power generation system is never reached in practice, and it does not consider other steps in power generation, such as production, transportation and storage of fuel and conversion of TMC Future Truck Committee Position Paper (2017-2) 2

3 the electricity into mechanical power. However, this calculation allows the comparison of different types of power generation. The maximum theoretical energy efficiency of a fuel cell is 83 percent, operating at low power density and using pure hydrogen and oxygen as reactants (assuming no heat recapture). [8] According to the World Energy Council, this compares with a maximum theoretical efficiency of 58 percent for internal combustion engines. [9] While these efficiencies are not approached in most real world applications, high-temperature fuel cells (solid oxide fuel cells or molten carbonate fuel cells) can theoretically be combined with gas turbines to allow stationary fuel cells to come closer to the theoretical limit. A gas turbine would capture heat from the fuel cell and turn it into mechanical energy to increase the fuel cell s operational efficiency. This solution has been predicted to increase total efficiency to as much as 80 percent. [10] Hydrogen fuel cells are efficient worthy of a PASS on a PASS/FAIL scale. Q: How reliable are hydrogen fuel cells? Fuel cells are very useful as power sources for equipment used in remote locations, such as spacecraft, remote weather stations, large parks, communications centers, rural locations, research stations, and in certain military applications. A fuel cell system running on hydrogen can be compact and lightweight, and have no major moving parts. Because fuel cells have no moving parts and do not involve combustion, in ideal conditions they can achieve up to percent reliability. [11] This equates to less than one minute of downtime in a six-year period. Stationary fuel cell applications typically require more than 40,000 hours of reliable operation at a temperature of 35 to 40 C ( 31 to 104 F), while [passenger] automotive fuel cells require a 5,000-hour lifespan (the equivalent of 240,000 km (150,000 mi)) under extreme temperatures. Current service life is 2,500 hours (about 75,000 miles). [12] Automotive engines must also be able to start reliably at 30 C ( 22 F) and have a high power-tovolume ratio (typically 2.5 kw per liter). At this time, durability (service life) appears too unacceptable by a factor of 14. Much work still needed. The U.S. Department of Energy's Fuel Cell Technology Program claims that, as of 2011, fuel cells achieved percent efficiency at one-quarter power and percent vehicle efficiency at full power, [13] and a durability of more than 120,000 km (75,000 mi) with less than 10 percent degradation. [14] The service life of fuel cells is comparable to that of other vehicles. [15] Proton exchange membrane (PEM) fuel cell service life is 7,300 hours under cycling conditions.[16] Conclusion: UNDETERMINED Overall, because of inconsistent reports, (e.g., 2,500 hour current service life versus 7,300 hours) durability cannot yet be rated on a PASS/FAIL scale. Q: Will a hydrogen fuel engine last as long as a diesel? Hydrogen internal combustion engine cars are different from hydrogen fuel cell cars. The hydrogen internal combustion car is a slightly modified version of the traditional gasoline internal combustion engine car. Conclusion: UNDETERMINED Unlike propane and CNG engines, comparisons between diesel and a hydrogen fuel cell vehicle are invalid at present. No PASS/FAIL grade is given. TMC Future Truck Committee Position Paper (2017-2) 3

4 Q: How long will it take to fill a hydrogen tank on a truck from empty? From onequarter full? Passenger automotive hydrogen-fueled vehicles can be refueled in less than five minutes. [17] This compares favorably with the time it takes to fill a passenger car with gasoline and presuming the time may be extrapolated to the larger truck-sized tanks, would be a reasonable comparison to a diesel fill. The manufacturer of a recently proposed hydrogen fuel cell truck (not yet in production) posts the claim that it can be filled in 15 minutes. Fill time, if accurately stated, is worthy of a PASS on a PASS/FAIL scale. Q: How much hydrocarbon energy is consumed in the production of hydrogen fuel and how does this compare to diesel? According to Ford Motor Company, when FCVs are run on hydrogen reformed from natural gas using this [steam-methane reforming process] process, they do not provide significant environmental benefits on a wellto-wheels basis (due to GHG emissions from the natural gas reformation process). [18] While methods of hydrogen production that do not use fossil fuel would be more sustainable, currently renewable energy represents only a small percentage of energy generated. [19] Power produced from renewable sources can be used in electric vehicles and for nonvehicle applications.[20] However, producing hydrogen using electrolysis of water, with the energy required for electrolysis provided by solar or wind or other non-hydrocarbon source, eliminates this concern. Hydrocarbon energy consumption is worthy of a PASS on a PASS/FAIL scale. Q: What would happen if a first responder used the jaws of life to cut open a wreck and, in the process, cut a line that released hydrogen? Do first responders need special training? Hydrogen collects under roofs and overhangs, where it forms an explosion hazard; any building that contains a potential source of hydrogen should have good ventilation, strong ignition suppression systems for all electric devices, and preferably be designed to have a roof that can be safely blown away from the rest of the structure in an explosion. It also enters pipes and can follow them to their destinations. Hydrogen pipes should be located above other pipes to prevent this occurrence. Hydrogen sensors allow for rapid detection of hydrogen leaks to ensure that the hydrogen can be vented and the source of the leak tracked down. As in natural gas, an odorant can be added to hydrogen sources to enable leaks to be detected by smell. While hydrogen flames can be hard to see with the naked eye, they show up readily on UV/IR flame detectors. [21] Hydrogen has been portrayed in the popular press as a relatively more dangerous fuel, and hydrogen in fact has the widest explosive/ ignition mix range with air of all gases except acetylene. However, this is mitigated by the fact that hydrogen rapidly rises and disperses before ignition, and unless the escape is in an enclosed, unventilated area, it is unlikely to be serious. Demonstrations have shown that a fuel fire in a hydrogen-powered vehicle can burn out completely with little damage to the vehicle, in stark contrast to the expected result in a gasoline-fueled vehicle. [22] An explosion of compressed hydrogen during delivery at the Muskingum River Coal Plant (owned and operated by American Electric Power) caused significant damage and killed TMC Future Truck Committee Position Paper (2017-2) 4

5 one person.[23] [24] For more information on incidents involving hydrogen, visit the U.S. DOE s Hydrogen Incident Reporting and Lessons Learned page. [25] The equivalent of a 52 mile-per-hour collision, directly onto a tank, caused nothing more than cosmetic damage. When a leak is detected, tank solenoid valves close, shutting off the flow of hydrogen and allowing the vehicle to safely shut down. Similarly, when collision sensors activate, the vehicle safely shuts down; tank solenoid valves close so that high-pressure hydrogen remains locked in the tank. In fuel cell vehicles, high-voltage relays open so highvoltage batteries or capacitors are isolated from the system. Tank solenoid valves will also close when the vehicle is turned off or the power is cut, and pressure relief devices will prevent the pressure inside the tank from becoming too high. (See Figure 1.) [26] Figure 1 Conclusion: UNDETERMINED Given the need for UV/IR flame detectors to detect day time fires, hydrogen would rate a FAIL on a PASS/FAIL scale. However, given Figure 2 the hydrogen-powered vehicle fire result and the 52 MPH drop test, it would rate a PASS. Thus, UNDETERMINED is the appropriate Q: How does hydrogen compare to diesel assuming diesel is $2.00 per gallon? rating at this time. Q: Will a driver need special gloves to fill the tank? No. Refueling a hydrogen vehicle is similar to refueling any other vehicle, and the same general safety rules apply drivers should not smoke or use cell phones while refueling. For safety, hydrogen tanks for vehicles are equipped with pressure relief devices that will prevent the pressures in the tanks from becoming too high. (See Figure 2.) This aspect of fueling is worthy of a PASS on a PASS/FAIL scale. U.S. DOE fuel cell bus analysis finds hydrogen fuel economy to be 1.4 times higher than diesel. [27] According to Nikola s web site, the proposed hydrogen fuel cell vehicle performed substantially better, but details of the test were incomplete. Conclusion: UNDETERMINED Energy equivalence is undetermined at this time. Thus, no grade could be given on a PASS/FAIL scale. Q: What driver and technician training guidelines exist? Are the training needs comparable to diesel, CNG or propane? TMC Future Truck Committee Position Paper (2017-2) 5

6 As with diesel engines, training for technicians will need to come from and be sponsored by the manufacturer or OEM. One OEM planning to introduce a hydrogen-powered vehicle has an nounced a national agreement with two firms to handle service work. What is unknown is if that same OEM will provide training to fleet service departments. As to general Safety concerns, consider taking the First Responders Training Class at FirstResponders/ tank is pierced in a full condition? How does this compare to propane, compressed natural gas and gasoline? As per Fig. 3 (fuels comparison chart) [28]: Gasoline has between 112,114 and 116,090 BTU/Gal. 1 kg or lbs. of hydrogen has 100 percent of the energy of one gallon of gasoline. Hydrogen provides 51,585 BTU/lb pounds of liquified natural gas (LNG) has 100 percent of one gallon of gasoline and 6.06 pounds of LNG has 100 percent Given the expectation that technician training of the energy of one gallon of diesel. LNG for a hydrogen fuel cell vehicle would be proprovides 21,240 BTU/lb. vided to experienced technicians by the same 5.66 pounds or cu ft. of CNG has source(s) and in the same manner as training 100 percent of the energy of one gallon is provided for other motive sources, such as of gasoline and 6.38 pounds or diesel engines; and given current availability of cu ft. of CNG has 100 percent of the what we feel is comprehensive safety training energy content of one gallon of diesel. program, provided by the DOE, we rate this as CNG provides 20,160 BTU/lb. a PASS, on a PASS/FAIL scale. Thus: 1 kg (2.198 pounds) of hydrogen is Q: How much damage could the hydrogen equivalent to 5.38 pounds of LNG or 5.66 in a truck fuel cell (tank) cause when the pounds of CNG. So, it is 2.45 times more Figure 3 TMC Future Truck Committee Position Paper (2017-2) 6

7 Conclusion: UNDETERMINED In our opinion, this factor is not one that can be reasonably rated on a PASS/FAIL scale. However, the Task Force is comfortable with what it has learned initially on the subject. Q: What is the damage radius when a tanker of hydrogen is ruptured? How does this compare to gasoline? Based upon the energy per pound, an equivalent weight of hydrogen would theoretically produce a damage radius 2.81 times the same weight of gasoline. However, the 52 MPH crash testing and the side-by-side results of a vehicle fire mentioned earlier provide some level of comfort. Figure 4 energy dense than LNG and 2.58 times more energy dense than CNG. Gasoline weighs pounds, so hydrogen is 2.81 times more energy dense per pound than gasoline. However, hydrogen s auto-ignition temperature is more than twice that of gasoline. The impact of the energy release, based upon a cursory examination of Reference [22], appears to be lower than that of gasoline (see Fig. 4). According to one hydrogen passenger vehicle manufacturer, The hydrogen fuel cell tanks are pressurized up to 10,000 psi, and hydrogen is 16 times lighter than air. So, if a tank were punctured or otherwise compromised, the hydrogen gas would instantaneously dissipate into the atmosphere. [29] As mentioned previously, if a hydrogen tank was punctured or otherwise compromised, the hydrogen gas would instantaneously dissipate into the atmosphere. John Kopasz, a scientist at the Argonne National Laboratory who performs research on hydrogen gas production, said that while there are inherent dangers with any combustible fuel, hydrogen fuel is safer than gasoline. [30] In our opinion, this factor can be reliably rated PASS on a PASS/FAIL scale, presuming the tanks are properly engineered. SUMMARY Table 1 summarizes the performance assessment of hydrogen fuel cell technology as it applies to trucking, based on TMC research. (See Table 1 on the following page.) TMC Future Truck Committee Position Paper (2017-2) 7

8 TABLE 1: PERFORMANCE ASSESSMENT SUMMARY FOR HYDROGEN FUEL CELLS QUESTION CONCLUSION Q: How efficient is hydrogen fuel cell technology? PASS Q: How reliable are hydrogen fuel cells? UNDETERMINED Q: Will a hydrogen fuel engine last as long as a diesel? UNDETERMINED Q: How long will it take to fill a hydrogen tank on a truck from empty? PASS From one-quarter full? Q: How much hydrocarbon energy is con sumed in the production PASS of hydrogen fuel and how does this compare to diesel? Q: What would happen if a first responder used the jaws of life to cut open a wreck and, in the process, cut a line that released UNDETERMINED hydrogen? Do first responders need special training? Q: Will a driver need special gloves to fill the tank? PASS Q: How does hydrogen compare to diesel assuming diesel is $2.00 UNDETERMINED per gallon? Q: What driver and technician training guidelines exist? Are the PASS training needs comparable to diesel, CNG or propane? Q: How much damage could the hydrogen in a truck fuel cell (tank) UNDETERMINED cause when the tank is pierced in a full condition? How does this compare to propane, compressed natural gas and gasoline? Q: What is the damage radius when a tanker of hydrogen is ruptured? How does this compare to PASS gasoline? REFERENCES [1a] [1b] USDOE Alternative Fuels Data Center, locations.html [2] Comparison of Fuel Cell Technologies. U.S. Department of Energy, Energy Efficiency and Fuel Cell Technologies Program, February 2011, accessed August 4, [3] Fuel Economy: Where the Energy Goes. Energy Efficiency and Renewable Energy, February 2011, accessed August 4, [4] FreedomCAR & Vehicle Technologies Program, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy [5] Ibid. [6] hbase/thermo/diesel.html Accessed June 30, [7] Types of Fuel Cells U.S. Department of Energy, Accessed August 3, [8] Fuel Cell Efficiency World Energy Coun cil, July 17, 2007, Archived February 9, 2014 at the Wayback Machine. Accessed August 4, TMC Future Truck Committee Position Paper (2017-2) 8

9 [9] Ibid. [10] Milewski, J.A. Miller and K. Badyda, The Control Strategy for High Temperature Fuel Cell Hybrid Systems The Online Journal on Electronics and Electrical Engineering, Vol. 2, No. 4, p. 331, 2009, Accessed August 4, [11] Wipke, Keith, Sam Sprik, Jennier Kurtz and Todd Ramsden, National FCEV Learning Demonstration National Renewable Energy Laboratory, April Accessed August 2, [13] Garbak, John, VIII.0 Technology Validation Sub-Program Overview U.S. Department of Energy, Fuel Cell Technologies Program, FY 2010 Annual Progress Report. Accessed August 2, [14] Accomplishments and Progress U.S. Department of Energy, Fuel Cell Technologies Program. June 24, [15] Energy Efficiency and Renewable Energy (EERE) Service Life 5000 Hours Accessed December 12, 2010 [16] Fuel Cell School Buses: Report to Congress. Accessed December 12, [17] Wipke, et. al. [18] Hydrogen Fuel Cell Vehicles (FCVs) Ford Motor Company. Accessed November 15, [20] Hell and Hydrogen March TechnologyReview.com. Accessed January 31, [21] safety [22] Hydrogen Car Fire Surprise January 18, Accessed May 9, [23] Williams, Mark, Ohio Power Plant Blast Kills 1, Hurts 9 Associated Press, January 8, [24] Muskingum River Plant Hydrogen Explosion American Electric Power, November 11, [25] Hydrogen Incident Reporting and Lessons Learned [26] FirstResponders/ [27] [28] [29] article/ /heres-why-hydrogen-fueledcars-arent-little-hindenburgs.html [30] Ibid. [19] F. Kreith, Fallacies of a Hydrogen Economy: A Critical Analysis of Hydrogen Production and Utilization. Journal of Energy Resources Technology (2004). 126: TMC Future Truck Committee Position Paper (2017-2) 9