A solution on the scale of the problem
The generally accepted solution to climate change is a world full of electric vehicles and an electricity grid powered by renewables and backed up by battery energy storage. This is not wrong, but it doesn’t tell the whole story. To comprehensively address climate change we must not only completely decarbonize the electricity grid, but the entire transportation sector and the industrial economy as well. And this cannot be done without green hydrogen. Green hydrogen is hydrogen that was produced from water and renewable electricity with zero emissions.
In a decarbonized transportation system, batteries are optimal where the distances are short, and the payload is light [1]. Electric scooters, motorbikes, passenger cars, and potentially even regional distribution vehicles are good examples. But with heavy payloads, long-haul freight, utility and military vehicles, mining vehicles, trains, ships, and airplanes — batteries are not a great option. All of these sectors are better suited for hydrogen fuel cells, another technology that is zero emissions when backed by renewables. This fundamental truth is confirmed by two simple observations.
First, the existing truck makers are pivoting to hydrogen fuel cell trucks through strategic partnerships — see Daimler, Volvo, Kenworth and Toyota [2] . Second, we have seen a number of new competitors enter the regional and heavy trucking space, including startups Nikola and Hyzon Motors. Hyzon Motors claims that it will produce a truck with a maximum range of 1200 miles and a refueling time of 10–15 minutes [3]. Compare that to the Tesla semi which claims a 400 mile range after a 30 minute charge, and 500 mile range with a full, multi-hour charge [4].
The basic reason for this mismatch in performance is that batteries are very heavy. A substantial portion of the power from a large battery is used transporting the battery, not the vehicle or payload. Hydrogen vehicles can extend their range by simply adding a larger fuel tank — 300 miles is the bottom end of the range for a passenger car, 750 miles for a long-haul semi — and refueling takes a few minutes, not hours. These are fundamental advantages.
In addition, the manufacturing of hydrogen fuel cells consumes significantly less raw materials than the manufacturing of batteries [1]. When manufacturing, operation and disposal are considered, fuel cell electric vehicles have lower GHG emissions over their life cycles than battery electric vehicles [5]. Following the same trend as other renewable technologies, the total cost of ownership for fuel cell electric vehicles is projected to fall by half over the next decade [6].
With the electricity grid, the issue is long term vs short term storage. Batteries are economical for short to medium term storage, performing best when storage duration is less than thirteen hours [7]. But batteries lose power over time and are an inefficient use of resources at the scale and duration required by a 100% renewable powered grid [7]. Green hydrogen, in contrast, can be stored indefinitely without losing energy value. From a fundamental perspective — battery performance will never satisfy the demands of a fully renewable power grid where the gap between when energy is produced and when it is needed can extend for months [8]. Filling seasonal energy gaps mandates long term energy storage, and only hydrogen provides that cost effectively at scale [1].
Hydrogen storage also offers valuable flexibility to the global energy picture. While charged batteries only produce electricity, hydrogen, a multipurpose fuel, can be sold for use outside of energy markets where emission reductions have been difficult to achieve. If we used renewables to supply the global economy with green hydrogen, it would allow the industrial sector to decarbonize [9].
The industrial sector emits over 15 gigatons of CO2 equivalent per year [9]. About half, 45%, is from the production of cement, steel, ammonia and ethylene [9]. Within that 45%, roughly half of CO2 emissions are a result of making the feedstock chemicals and a third the result of burning fuels for high-temperature heat [9]. Within each of these industries, only hydrogen offers a path to full decarbonization [9].
For example, cement can be produced with kilns that burn hydrogen [9]. The combustion of hydrogen with oxygen produces water and heat with no CO2 emissions. This would reduce the emissions of cement manufacturing by 40% [9]. Producing ethylene, a process that requires high quality heat, could also be completely decarbonized in part by having that heat sourced from the combustion of hydrogen [9]. Direct reduced iron (DRI), a method for manufacturing steel that typically uses methane can use hydrogen instead, giving a pathway to the complete decarbonization of steel production [10] [9].
If climate justice is to be achieved, it will ultimately transpire from decarbonization of the industrial sector. That’s because industrial facilities are a central source of climate injustice, spewing significant amounts of carbon and other hazardous emissions into the surrounding environment. This places a well-documented and disproportionate health burden on poor and working class families who live in areas surrounding industrial plants [11]. By feeding green hydrogen to dirty industrial plants, we can reduce the industrial sectors net emissions to zero [9].
Consider ammonia production — like the kind that occurs in Baton Rouge, Louisiana [11]. Replacing methane with clean hydrogen in the Haber process would completely eliminate carbon emissions from this toxic industry. Just this step alone would translate to a reduction of half a gigaton of CO2 emissions [9]. That has big implications for residents of a city like Baton Rouge, where citizens have a disproportionately high cancer rate.
Industrial plants will have to be retrofitted in some cases, and rebuilt in others, but nonetheless, green hydrogen offers a real solution. Not to mention it is one that keeps jobs in communities while zeroing out emissions, providing both environmental justice and economic opportunity to those who have been systematically harmed.
Hydrogen provides the missing link to a completely green economy by allowing society to convert renewable power into a carbon-free commodity at low cost. That’s important because hydrogen is a critical integration point between intermittent clean power generation, the entire transportation sector, and the industrial sector. We need this integration to achieve 100% decarbonization.
To beat climate change - we need a hydrogen economy.
The views expressed in this article are my own and do not in any way represent my employer.
References
[1] Hydrogen Europe, “Hydrogen Roadmap Europe,” Bietlot, Belgium, 2019.
[2] J. Hirsch, “News,” Trucks.com, 21 April 2020. [Online]. Available: https://www.trucks.com/2020/04/21/daimler-volvo-hydrogen-fuel-cell-truck/. [Accessed 29 July 2020].
[3] H. Morgan, “Fuel Cell Works,” Rethink Technology Research, 6 April 2020. [Online]. Available: https://fuelcellsworks.com/asia/hyzon-aims-for-tesla-style-rush-to-market-for-hydrogen-trucks/. [Accessed 29 July 2020].
[4] J. O’Dell, “News,” Trucks.com, 19 September 2019. [Online]. Available: https://www.trucks.com/2019/09/05/everything-we-know-about-the-tesla-semi-truck/. [Accessed 29 July 2020].
[5] D. A. Sternberg, “Overview of Zero Emission (ZE) Driving Options — Life Cycle Comparison of Electric and Fuel Cell Vehicles,” Fraunhofer Institute for Solar Energy Systems, Hamburg, 2019.
[6] B. a. Deloitte, “Fueling the Future of Mobility,” Deloitte China, 2020.
[7] Michael Penev, Neha Rustagi, Chad Hunter, Josh Eichman, “Energy Storage: Days of Service,” National Renewable Energy Laboratory, 2019.
[8] Jason Finkelstein, David Frankel, and Jesse Noffsinger, “How to decarbonize global power systems,” McKinsey & Company, 2020.
[9] Arnout de Pee, Dickon Pinner, Occo Roelofsen, Ken Somers, Eveline Speelman, Maaike Witteveen, “Decarbonization of the industrial sectors: the next frontier,” McKinsey & Company, The Netherlands, 2018.
[10] M. Mazengarb, “Another nail in coal’s coffin? German steel furnace runs on renewable hydrogen in world first,” Renew Economy, 13 November 2019. [Online]. Available: https://reneweconomy.com.au/another-nail-in-coals-coffin-german-steel-furnace-runs-on-renewable-hydrogen-in-world-first-55906/. [Accessed 12 May 2020].
[11] L. Y. J. M. Tristan Baurick, “POLLUTER’S PARADISE — Welcome to “Cancer Alley,” Where Toxic Air Is About to Get Worse,” ProPublica, 30 October 2019. [Online]. Available: https://www.propublica.org/article/welcome-to-cancer-alley-where-toxic-air-is-about-to-get-worse. [Accessed 30 July 2019].
[12] H. Edwardes-Evans, “Green hydrogen costs ‘can hit $2/kg benchmark’ by 2030: BNEF,” S&P Global, 30 March 2020. [Online]. Available: https://www.spglobal.com/platts/en/market-insights/latest-news/coal/033020-green-hydrogen-costs-can-hit-2kg-benchmark-by-2030-bnef. [Accessed 11 May 2020].
