The Hydrogen Economy refers to a vision of hydrogen becoming the primary energy source. The vision of hydrogen as a primary energy source is compelling. Hydrogen can be a feedstock for chemical processes, as well as a fuel for heat, power generation and propulsion of vehicles. The hydrogen combustion is clean, no CO2 emissions, only water. Hydrogen can be stored and transported. The “only” problem is that hydrogen is not naturally available on the earth. The hydrogen must be produced!
Presently, most hydrogen is industrially produced from steam reforming of natural gas. The process emits CO2. Only about 2% of the hydrogen is produced through electrolysis of water. This process is clean, no CO2, but the cost for the hydrogen through electrolysis is 2 to 3 times more expensive than compared to steam reforming of natural gas. However, with reduced cost for the electrolyzers and lower electricity costs, expectations are that there is a path forward for the cost of electrolysis to drop substantially.
The origin of the hydrogen vision can be traced to February 4, 1923 in a paper written and read by the British scientist J.B.S. Haldane, “Daedalus or Science and the Future”. Concerned that coal and oil fields would be exhausted in centuries only, Haldane’s vision for England was windmills coupled with electrolysis of water into hydrogen and oxygen. The hydrogen could be liquified and stored for calm days. Haldane recognized that “the initial costs would be very considerable”, but he said that “the running expenses would be less than those of our present system” and also that “no smoke or ash will be produced”. Indeed visionary, but 100 years ago very few shared Haldane’s concerns and he seems to have been more or less alone in his vision.
Fast forward to 1970. Several developments triggered new interest in hydrogen. With the emergence of commercial nuclear power expectations were high on low cost electric energy. Also, commercial cryogenic processing industry had emerged in the late 1960s, making liquid hydrogen viable. If hydrogen could be commercially available at a large scale, hydrogen may be the future energy source for air and vehicular transportation. So was the thought expressed by the Italian scientist and lecturer at Cornell University Cesare Marchetti, Professor Lawrence W. Jones, University of Michigan, and others. Discussing a long-term solution to conservation and air quality related pollution professor Jones wrote a paper, “Toward a liquid hydrogen fuel economy”, in March 1970. Jones identified both the technical opportunities as well the economic challenges.
The phrase “hydrogen economy” was coined by John Bockris during a presentation he gave 1970 at General Motors Technical Center. Bockris later, in the early 1980s, announced several claims of major progress in his hydrogen-fuel technology. These claims turned out to be wrong.
Overcoming the 1973 and 1978 oil crisis, the interest in hydrogen faded away, but did not die. Renewed interest in hydrogen started to resurface around 2000. As Jeremy Rifken lays out in his book “The Hydrogen Economy (2002)” the main drivers behind the interest was a combination of concerns of peak oil around the corner and expectations of fuel cells replacing reciprocating engines for cars.
Department of Energy (DOE) formed the Hydrogen Fuel Initiative in 2004 with increased federal funding for hydrogen and fuel cell research, development, and demonstration to $1.2 billion over five years. It had the support of the automotive companies. GM had pulled the plug on its EV1 in 1999. Despite this substantial support, progress was limited. GM/Chevrolet launched Equinox FC in 2007 but stopped production two years later. Other companies selling or leasing fuel cell cars were Honda, Toyota, Nissan, and Mercedes-Benz. Today, only Toyota, Huyndai and Honda sell or lease fuel cell cars, only in select markets and in limited quantities.
The slow progress can be attributed to several challenges, technical and economical, including access to hydrogen. The hydrogen had to be produced! Either you produced the hydrogen with an onboard reformer in the car, which added weight and cost, or centrally, but then you needed an infrastructure to deliver the hydrogen to fueling stations, which did not exist.
More important, several paradigm shifts started to happen around 2006-2008. The shale gas and shale oil revolutions resulted in inexpensive gas and oil, moving the concerns for peak oil and peak gas much further out. The cost for renewable energy, wind and solar, started to come down most significantly. Same thing for lithium ion batteries, which made their debut in plug-in electric vehicles like Tesla Roadster (EV introduced 2008), GM Volt (PHEV 2010) and Nissan Leaf (EV 2010). Maybe, the most profound change was the shift in focus from reduction of air-quality related emissions to reduction of carbon dioxide and other greenhouse gases.
With almost all commercial hydrogen produced through steam reforming of hydrocarbons releasing CO2, the hydrogen vision faded. It probably had faded into oblivion, if not, about three years ago (2017) the concept of “green hydrogen” started to surface.
“Green hydrogen” refers to hydrogen produced by clean energy, primarily renewable energy, powering electrolyzers splitting water into hydrogen and oxygen. “Grey hydrogen” is used for hydrogen produced from natural gas. If the CO2 from the process is captured, used, or sequestered, the produced hydrogen is called “blue hydrogen”.
So, what are the drivers behind the interest in “green hydrogen”? Wind and solar has come down so much in cost that they can offer very competitive electricity prices. There is also the challenge of periods of excess power from wind and solar, as seen in countries and states with high penetration of wind and solar like California, where at times solar and wind has had to be curtailed. The amount is not insignificant. In 2019 California nearly 1 MWh of solar and wind energy was wasted due to curtailments. Germany has also due to electric transmission constraints at times curtailed wind in the north. On the demand side it is recognized that it will be difficult to decarbonize parts of the transportation and industrial sectors by electrification. For example, if you want to replace kerosene for an aircraft with a synthetic fuel you will need hydrogen to produce the synthetic fuel.
Next question is how hydrogen stacks up against electricity? The answer is that it depends, but in general electricity wins. Agora Energiewende points out that the first priority in decarbonization options is direct use of electricity. As they show the overall energy efficiency for an EV passenger car is 69%. For a fuel cell car, the efficiency is 26% and for an internal combustion engine car it is 13%. However, for long-haul trucks and buses as well as air and sea transport hydrogen, directly or indirectly as a synthetic fuel, can be viable alternatives. For long duration energy storage, with up to 1-week discharge, hydrogen could become cost efficient in the near future, according to researchers at DOE NREL.
Japan was first out with a “Basic Hydrogen Strategy”, adopted in 2017. The goal is to make hydrogen a cheaper energy carrier. However, the strategy is about hydrogen, regardless of its color of production. In terms of green hydrogen, a 10 MW pilot project, Fukushima Hydrogen Energy Research Field (FH2R) using renewable energy for the electrolysis is expected to come online next year (2021).
Focused on growing the role of green hydrogen is Germany’s recently (July 2020) announced €9 billion plan. It aims at 5 GW of green hydrogen production capacity by 2030 and another 5 GW by 2040. The plan is part of a large stimulus package related to COVID-19 by the German Government.
Even more visionary is “The 2×40 GW Green Hydrogen Initiative” for Europe, Ukraine, and North Africa. It is promoted by Hydrogen Europe Industry, an association with over 160 members. Other advocacy groups for hydrogen is the Hydrogen Council, launched in Davos at the World Economic Forum 2017, and the US based Green Hydrogen Coalition, founded in 2019.
In July, this year (2020) NextEra presented its plan for a $65 million pilot plant in Florida by 2023. It will use solar power, which “otherwise would have been clipped” (Rebecca Kujawa, NextEra Energy CFO) and have a 20 MW electrolyzer. The intent is to use the green hydrogen to replace a portion of the natural gas for an existing combined cycle gas turbine (CCGT) power plant.
So, what can we expect for the next 30 years? A true hydrogen economy with a built-out hydrogen infrastructure seems to remain an elusive vision, but green hydrogen will supplement electricity and be part of a decarbonized economy. Green hydrogen will most likely grow, but much dependent on government subsidies.
See more: Energy Innovation has developed an open-source tool, Energy Policy Simulator.