If you’re an electric utility executive, government policy maker, or environmentalist, what do you do with power generated from wind, solar, nuclear, or hydro? [1-4]
Make electricity. Don’t buy into the expensive idea that hydrogen can serve as the global energy storage medium of the future.
Hydrogen is great...for hydrocracking, hydro-desulfurization, hydrogenation, making ammonia for fertilizer, and a few niche industrial applications. [5]
Transportation isn’t one of those applications, and neither is the use of hydrogen as a replacement for natural gas combustion in turbines—Even If Hydrogen Is Free.
First up is the case against hydrogen for transportation. Then on to power generation.
Why Hydrogen is Such a Bad Idea for Cars and Trucks
The thermodynamic costs, costs to make it usable (compression is needed due to its low energy density), operations and maintenance costs, and capital costs make it too expensive. The easiest way to demonstrate the business case killing cost of hydrogen is to list the immutable thermodynamic losses associated with transportation.
The Thermodynamic Losses
Losses from Making Hydrogen
To use hydrogen, it must first be manufactured by: (1) electrolysis of water, or (2) fossil fuel reforming. The conversion efficiency of alkaline electrolysis, the most common and cheapest type of electrolyzer technology, is 70-80% on a lower heating value (LHV) basis [6]. Nearly all commercial hydrogen today, approximately 95%, is manufactured by reforming natural gas, oil, or coal. However, this results in carbon emissions and also results in a major efficiency loss similar to that of electrolysis of water (i.e., using electricity to extract the H from H2O). Figure 1 shows the CO2 emissions per equivalent kilometer traveled for a gasoline vehicle versus a variety of ways to produce hydrogen via electrolysis. Using 100% renewable power results in the lowest emissions (zero). However, this is not projected to occur at scale for the foreseeable future [7].
source: ICCT
Figure 1. CO2 Emissions from Gasoline Vehicles, Renewable Electrolysis, and Reforming
Losses from Compressing Hydrogen
To use hydrogen in fuel cell vehicles, it must be compressed to 3,000 pounds per square inch gauge (psig) or more onboard the vehicle, and upwards of 12,000 to 14,000 psig in filling station tanks using a complex series of specialized compression equipment and tanks (Figure 2). Losses associated with compression (and cooling) to 5,000 to 10,000 psig, typical of fuel cell vehicle tanks is approximately 30% (i.e., 70% compressor efficiency) [8].
source: M. Zerega
Figure 2. Typical Hydrogen Compressor and Fueling Station
Hydrogen storage isn’t free. Figure 3 shows the relative cost three high pressure hydrogen tanks typically required for a fuel cell vehicle versus the cost and weight of a gasoline can.
source: M. Zerega
Figure 3. Typical Hydrogen Tanks and Costs versus Gasoline
Losses from Converting Hydrogen to Electricity Via Fuel Cells
Hydrogen is combined with air, via fuel cell, into electricity and water. This process, using proton exchange membrane (PEM) fuel cell technology is about 40% efficient. The power electronics conversion to condition electricity for the drive train results in further losses of 5-10%, which is typical of electric drive trains.
Figure 4, from Transport & Environment (T&E), shows that the efficiency for hydrogen is little better than using diesel or gasoline in a combustion engine, but the comparison excludes the energy required for compression. This would make things worse for hydrogen. An EV is a factor of three more efficient. This means that three times more renewable power would have to be generated for a fuel cell vehicle to travel the same distance as an EV. [9]
source: Transport&Environment
Figure 4. EV Efficiency versus Hydrogen Fuel Cell Vehicles and ICEs
Hydrogen – The O&M, CAPEX and Other Losses
Economic Losses
As if production, compression/cooling, and conversion losses aren’t enough, these processes require capital expenditures (CAPEX) for equipment, and operations and maintenance (OPEX) to keep the equipment running. The manufacturer of hydrogen must buy, operate, and maintain the electrolyzers, compressors, and other equipment necessary to condition the hydrogen for use in a fuel cell vehicle or gas-fired power plant (also known as balance-of-plant). In the case of fuel cell vehicles, a fuel cell fueling station is also needed (bought, installed, operated, and maintained) at a typical initial cost of $2M. [10, 11]
This isn’t to say that electric charging infrastructure is free. However, EVs don’t start with hydrogen’s low energy density, and corresponding fuel transportation challenges, and large thermodynamic losses. EV charging infrastructure O&M costs are relatively minor compared to that of hydrogen.
Water Losses
Electrolysis requires water to produce hydrogen. The amount of water required can be significant, especially for regions that are challenged for water resources, which includes many parts of the world. Instead of using limited water resources to make hydrogen, a more appropriate application in water-constrained regions might be to produce potable water via desalination, instead of using limited water resources to make hydrogen.
What About Trucks and Buses?
Years ago, hydrogen was thought to be a great option for zero emission heavy-duty trucks and buses. Since then, batteries have continued to improve, and the business case for electrification for almost all on-road transportation has only become more compelling. The best case for fuel cell heavy duty trucks was the long-haul case study. Surely, if an electric Class 8 heavy-duty truck had to carry all those batteries, it would take forever to recharge, and the weight of the batteries would displace valuable cargo. However, most heavy-duty trucks, and buses for that matter, operate short haul routes. This allows overnight charging and opportunity fast charging to service the daily routes. [12]
Yes, but what about the long-haul trucker who makes a living driving across the US? Hyzon and Nikola are developing fuel cell heavy-duty trucks [13]. However, Nikola is hedging its bet by also developing an electric heavy-duty truck. Long haul electric trucks will reportedly use 300- to 500-mile range batteries that can be recharged in one to two hours.
Figure 5 shows an analysis of the additional cost of energy infrastructure, truck vehicle purchase, and total cost for electric (catenation), for power conversion-to-methane and power conversion-to-hydrogen, versus the base case of power-to-liquid combustion. The hydrogen case is almost three times the total cost of electric for the long-haul heavy-duty freight transport sector in Germany.
source: ICCT
Figure 5. Additional cost for four different greenhouse gas reduction scenarios [14]
In January 2020, the Society of Automotive Engineers (SAE) issued J3105, the standard for heavy-duty EV charging. This standard allows for charging of up to 1.2 MW (1,000 VDC, 1,200A). If that isn’t enough power, the group CharIN, in conjunction with Daimler and other organizations is developing charging technology called the Megawatt Charging System (MCS) that allows for charging up to 3 MW.
Figure 6 shows a chart from Transport & Environment similar to Figure 4, but for trucks [9]. Lawrence Berkeley National Labs released a report that detailed the benefits of electrifying regional and long-haul heavy duty trucks [15]. Has the last potential hydrogen use case for transportation evaporated?
source: Transport & Environment
Figure 6. Electrified Truck Efficiency versus Hydrogen Fuel Cell Vehicles and ICEs
What About Ships and Airplanes?
Battery-powered cruise ships may not be around the corner, but battery-powered tugs and ferries are. But then, fuel cell-powered cruise ships may not be practical, either. Possibly, the most carbon-neutral solution might be renewable fuel-powered cruise ships and passenger jets. However, Asahi Tanker has ordered two ship tankers fitted with 3.5 MWh batteries. Electrification of small aircraft is also attracting a lot of attention. [16, 17]
What About Combustion?
Couldn’t electric utilities produce green hydrogen from wind and solar (hydrogen via renewables) and burn it in gas-fired turbines and displace natural gas for free?
No.
First, we consider the purely financial reason against using green hydrogen in power plants. Almost no green hydrogen is produced today [18, 19]. In the interim twenty to thirty years required to get to a meaningful production scale (c.2040), we will continue to produce black (coal), brown (natural gas), and possibly blue hydrogen (natural gas with carbon capture). Still, green hydrogen is projected to be more expensive than the other varieties. A suspicious person might wonder who would benefit from this phased timeline. [20-26]
Next, we consider the technical reasons hydrogen is a bad idea. Existing natural gas pipelines and compressors aren’t designed for hydrogen [27]. Neither are the combustion turbines. Pure, pressurized, hydrogen causes embrittlement and blistering in carbon steel tanks and pipelines. New pipelines, compressors, and other equipment would be required to make this transition [28]. Plus, hydrogen has a higher flame temperature than natural gas, which causes higher NOx emissions. [29]
Hydrogen could be blended in low percentages of 15-30% in an effort to minimize such materials issues [30]. While this could contribute to CO2 emissions reduction if it were green hydrogen, that won’t be the case in the near-term. In the long-term, the 100% green hydrogen costs appear to be a non-starter.
Mitsubishi and others point to hydrogen-produced ammonia as the path forward. Mitsubishi plans to design a 40 MW gas turbine fueled by ammonia [31]. Ammonia could also be used as a shipping fuel. However, producing ammonia requires an additional step in an already expensive process. While this works for fertilizer, which has a relatively high commercial value, the ammonia combustion business case, which would be a pure commodity, may be doubtful. Another problem with ammonia is safety. Ammonia is typically stored in tanks in its anhydrous form, which is classified as an acutely hazardous material. Traditional industries that use anhydrous ammonia undergo process hazard assessments and risk management plans to ensure it’s handled properly. Staff in industries new to ammonia would require extensive training, which could introduce a paradigm shift for those without a historical safety culture in place.
However, even if combustion turbines could operate efficiently with hydrogen or ammonia, what would be the point?
The Rocky Mountain Institute and others have projected that natural gas powered generation will result in stranded assets by the mid-2030s, meaning the power plants won’t be economical to operate by that time frame, which is what’s happening to today’s coal-fired power plants [32-34]. New natural gas power generation is already less economical (on a levelized cost of ownership – LCOE basis) than wind and solar—and this is with natural gas at historic lows in cost per million BTUs. If natural gas combustion turbines (including O&M costs) are not economical, replacing natural gas with green hydrogen or green ammonia, which is more expensive, won’t be economical, either. Why prolong the agony of stranded assets further?
Conclusion
Do you believe in hydrogen? Well, yes. It’s number one on the periodic chart. It’s abundant. It powers suns. And without it, we wouldn’t have water.
The real question is: which applications would benefit from use of hydrogen, and which won’t? Just because you can do something, doesn’t mean you should. If the economics, thermodynamics, and safety aspects say green hydrogen is not appropriate for the vast majority of transportation and power generation applications, then this is a distraction the world cannot afford. [35, 36]
No breakthrough in technology will do away with electrolyzer or compressor energy losses. These are fundamental physical processes.
For transportation and power generation, even if hydrogen is free, it’s not cheap enough.
Acknowledgements
The author would like to acknowledge the very helpful contributions and advice of Mr. Matt Zerega and Mr. Mike Ferry.
References
1. Corporate European Observatory, The Hydrogen Hype: Gas Industry Fairy Tale or Climate Horror Story?, CorporateEuropeanObservatory.org, Foodandwatereurope.org, recommon.org, https://corporateeurope.org/sites/default/files/2020-12/hydrogen-report-web-final_3.pdf, December 2020.
2. CarbonBrief, https://www.carbonbrief.org/in-depth-qa-does-the-world-need-hydrogen-to-solve-climate-change, November 2020.
3. Arnold, R. Green Hydrogen and Unicorns, Energy Central, https://energycentral.com/c/cp/green-hydrogen-and-unicorns, February 2021.
4. Bousso, R., S. Kelly, Energy Firms Bet on Hydrogen Boom, But Payday Far Away, Reuters, Energy & Environment, https://www.reuters.com/article/us-ceraweek-hydrogen/energy-firms-bet-on-hydrogen-boom-but-payday-far-away-idUSKBN2AV1R2, March 2021.
5. Brown, A., Uses of Hydrogen in Industry, The Chemical Engineer, https://www.thechemicalengineer.com/features/uses-of-hydrogen-in-industry/, July 2019.
6. US Department of Energy, DOE Technical Targets for Hydrogen Production from Electrolysis, DOE Hydrogen and Fuel Cell Office, https://www.energy.gov/eere/fuelcells/doe-technical-targets-hydrogen-production-electrolysis, accessed March 2021.
7. Christensen, A., Assessment of Hydrogen Production Costs from Electrolysis; United States and Europe, The International Council On Clean Transportation (www.theicct.org), https://theicct.org/sites/default/files/publications/final_icct2020_assessment_of%20_hydrogen_production_costs%20v2.pdf, June 2020.
8. Parks, G., R. Boyd, J. Cornish, and R. Remick, Hydrogen Station Compression, Storage, and Dispensing Technical Status and Costs, National Renewable Energy Laboratory, NREL/BK-6A-58564, https://www.nrel.gov/docs/fy14osti/58564.pdf, May 2014.
9. Decock, G., Electrofuels? Yes, We Can…If We’re Efficient, Transport & Environment, https://www.transportenvironment.org/sites/te/files/publications/2020_12_Briefing_feasibility_study_renewables_decarbonisation.pdf, December 2020.
10. Isenstadt, A., and N. Lutsey, Developing Hydrogen Fueling Infrastructure for Fuel Cell Vehicles: A Status Update, The International Council On Clean Transportation (www.theicct.org), https://theicct.org/sites/default/files/publications/Hydrogen-infrastructure-status-update_ICCT-briefing_04102017_vF.pdf, October 2017.
11. Wood Mackenzie, Green Hydrogen Production: Landscape, Projects and Costs, Executive Summary, Wood Mackenzie Power & Renewables, https://www.woodmac.com/reports/energy-markets-executive-summary-green-hydrogen-production-landscape-projects-and-costs-392370, October 2019.
12. Morris, C., Prominent Energy Researcher Believes in Electric Trucks Over Fuel Cells, insideevs.com, https://insideevs.com/features/462434/energy-researchers-electric-trucks-win/, December 2020.
13. Stinson, J., Why Transport Buyers Tell Hyzon Hydrogen is a “No Brainer”, Utilitydive.com, https://www.utilitydive.com/news/Hyzon-fuel-cell-plant-EV-electric-truck/596103/, March 2021.
14. Moultak, M., N. Lutsey, and D. Hall, Transitioning to Zero-Emission Heavy-Duty Freight Vehicles, The International Council On Clean Transportation (www.theicct.org), https://theicct.org/sites/default/files/publications/Zero-emission-freight-trucks_ICCT-white-paper_26092017_vF.pdf, September 2017.
15. Phadke, A, etal., Why Regional and Long-Haul Trucks Are Primed for Electrification Now, Lawrence Berkeley National Laboratory Contract No. DE-AC02-05CH11231. https://eta-publications.lbl.gov/publications/why-regional-and-long-haul-trucks-are. March 2021.
16. Gallucci, M., The First Battery-Powered Tanker is Coming to Tokyo, IEEE Spectrum, https://spectrum.ieee.org/energywise/energy/batteries-storage/first-battery-powered-tanker-coming-to-tokyo, February 2021.
17. Morris, C., Is Aviation the Best Application Yet for Hydrogen Fuel Cells?, Charged EVs Magazine, https://chargedevs.com/features/is-aviation-the-best-application-yet-for-hydrogen-fuel-cells/, February 2021.
18. International Energy Agency, IEA 2020 Energy Technology Perspectives,https://webstore.iea.org/download/direct/4165, February 2021.
19. BloombergNEF, Hydrogen Economy Outlook, BloombergNEF, https://data.bloomberglp.com/professional/sites/24/BNEF-Hydrogen-Economy-Outlook-Key-Messages-30-Mar-2020.pdf, March 2020.
20.Thomas, N., and D. Sheppard, The Race to Scale Up Green Hydrogen, Financial Times,https://www.ft.com,March 2021.
21. Franz, S., Hydrogen, Don’t Give Up, PV Magazine, https://www.pv-magazine.com/2018/04/09/hydrogen-dont-give-up/, April 2018.
22. Mikulka, J., Decoding the Hype Behind the Natural Gas Industry’s Hydrogen Push, Desmogblog.com, https://www.desmogblog.com/2021/01/14/decoding-hype-behind-natural-gas-industry-hydrogen-push, January 2021.
23. Kahya, D., Unearthed today: Why oil companies want you to love hydrogen, unearthed.greenpeace.org, https://unearthed.greenpeace.org/2020/12/08/unearthed-today-why-oil-companies-want-you-to-love-hydrogen/, August 2020.
24. Grant, A., and P. Martin, Hydrogen is Big Oil’s Last Grand Scam, cleantechnica.com, https://cleantechnica.com/2021/02/24/hydrogen-is-big-oils-last-grand-scam/amp/, February 2021.
25. Deign, J., The Reality Behind Green Hydrogen’s Soaring Hype, greentechmedia.com, https://www.greentechmedia.com/articles/read/the-reality-behind-green-hydrogens-soaring-hype, November 2020.
26. Mikulka, J., Major Fossil Fuel PR Group is Behind Europe Pro-Hydrogen Push, Desmogblog.com, https://www.desmogblog.com/2020/12/09/fti-consulting-fossil-fuel-pr-group-behind-europe-hydrogen-lobby, December 2020.
27. Menzies, M.,Hydrogen: The Burning Question, The Chemical Engineer, https://www.thechemicalengineer.com/features/hydrogen-the-burning-question/, accessed March 2021.
28. Zahreddine, Hafsi, M. Mishra, and S. Elaoud, Hydrogen Embrittlement of Steel Pipelines During Transients, Elsevier, https://www.sciencedirect.com/science/article/pii/S2452321618302683, 2018.
29. Zeldovich, Y. A., P. Y. Sudovnikov, and D. A. Frank-Kameneskii, Oxidation of Nitrogen in Combustion, translated by M. Shelef, Academy of Sciences of the U.S.S.R., Institute of Chemical Physics, Moscow, 1947.
30. Melaina, M.W., O. Antonia, and M. Perez, Blending Hydrogen into Natural Gas Pipeline Networks: A Review of the Issues, National Renewable Energy Laboratory, NREL/TP-5600-51995, https://www.energy.gov/sites/prod/files/2014/03/f11/blending_h2_nat_gas_pipeline.pdf, March 2013.
31. Mitsubishi, Mitsubishi Power Commences Development of World’s First Ammonia-Fired 40 MW Class Gas Turbine System, Mitsubishi Press Release, https://power.mhi.com/news/20210301.html, March 2021.
32. Dyson, M., A Bridge Backward? The Risky Economics of New Natural Gas Infrastructure in the United States, Rocky Mountain Institute, https://rmi.org/a-bridge-backward-the-risky-economics-of-new-natural-gas-infrastructure-in-the-united-states/, September 2019.
33. AEMC, AEMC Looks Beyond Coal and Gas to Batteries and Flexible Grid to Manage Reliability, https://www.globalenergyworld.com/news/sustainable-energy/2021/03/04/aemc-looks-beyond-coal-gas-batteries-flexible-grid-manage-reliability, March 2021.
34. Trabish, H., “A Total Mindshift”: Utilities Replace Gas Peakers, “Old School” Demand Response with Flexible DERs , UtilityDive.com, https://www.utilitydive.com/news/a-total-mindshift-utilities-replace-gas-peakers-old-school-demand-res/595415/, March 2021.
35. Evans, S. and J. Gabbattis, In-Depth Q&A: Does the World Need Hydrogen to Solve Climate Change?, CarbonBrief, https://www.carbonbrief.org/in-depth-qa-does-the-world-need-hydrogen-to-solve-climate-change, December 2020.
36. Messagie, M., Life Cycle Analysis of the Climate Impact of Electric Vehicles, Transport & Environment, https://www.transportenvironment.org/sites/te/files/publications/TE%20-%20draft%20report%20v04.pdf, draft 2021.
Author
Charles Botsford, PE is a professional chemical engineer in the State of California with 30 years’ experience in engineering process design, distributed generation, EV charging infrastructure, and environmental management. He participated in California’s Vehicle Grid Integration (VGI) Working Group and participates in the Society of Automotive Engineers (SAE) J3072 AC Vehicle-to-Grid standards committee. Mr. Botsford holds a master’s and bachelor’s degree in chemical engineering, and served as hazards and operability (HAZOP) team leader to analyze one of the largest anhydrous ammonia facilities in the U.S.