For a long time, hydrogen has been considered as an alternative to fossil fuels and a potentially valuable tool to combat climate change.
Today, as countries put forward a zero-net strategy to align with their international climate goals, hydrogen has once again become the focus of attention from Australia and the United Kingdom to Germany and Japan.
In the most optimistic outlook, hydrogen can quickly power trucks, airplanes and ships. It can heat houses, balance the power grid and help heavy industry manufacture everything from steel to cement.
But doing all these things with hydrogen will require an incredible amount of fuel, which is only as clean as the method of producing it. Moreover, for each potential conversion application of hydrogen, unique challenges must be overcome.
In this in-depth Q&A, including a series of charts, maps and interactive charts, as well as the opinions of dozens of experts, Carbon Brief examines the major issues surrounding the “hydrogen economy” and explores the extent to which they can be solved Hydrogen problem. Help the world avoid dangerous climate change.
Hydrogen is the lightest and most abundant element in the universe. It is also an explosive and clean burning gas, which contains more energy per unit weight than fossil fuels.
In the hydrogen economy, hydrogen will replace fossil fuels, which currently account for four-fifths of the world’s energy supply, and emit most of the global greenhouse gases.
This may help achieve climate goals because hydrogen releases water only when it is burned, and does not release carbon dioxide during the manufacturing process. (Its production currently emits 830 million tons of CO2 [MtCO2] annually.)
The hydrogen economy may be all-encompassing. Or, for each potential application, depending on hydrogen availability, cost, and performance relative to alternatives, it may fill a series of gaps.
Between these two extremes, hydrogen still has the potential to play a huge role in achieving net zero emissions, which requires a significant increase in its production and use.
“Are you for or against hydrogen? This seems to be a wrong question. I think the question is: Where do you really need to use it?” said Dr. Jan Rosenow, who oversees the aid project.
Timur Gül, head of the energy technology department of the Paris-based International Energy Agency (IEA), said that hydrogen energy can help solve “critical” industries that are difficult to reduce emissions, such as steel and long-distance transportation, and lead its 2019 report on the future of hydrogen. He told Carbon Brief:
“I think hydrogen has an important place in it, but… I think if your goal is to achieve net zero emissions, then you don’t want to build a hydrogen economy, but to find a decarbonized energy sector. This is to achieve A means of purpose.”
Hydrogen can be produced by splitting water with electricity (electrolysis) or by using “reforming” or “pyrolysis” to decompose fossil fuels or biomass with heat or steam. Any carbon dioxide can be captured and stored.
Hydrogen can be stored, liquefied and transported through pipelines, trucks or ships. It can be used to make fertilizer, fuel cars, heat houses, generate electricity or drive heavy industry.
The figure below shows this potential hydrogen “economy”. These illustrations have numbered titles from one to three, showing how to make, move, and use hydrogen.
Some advocates of the hydrogen economy describe a broad vision for the future, which will replace most of the social, economic and geopolitical positions currently occupied by fossil fuels.
“In the past, our technology and industry all collected oil, transported oil, and used oil. Now, in the future, it will collect sunlight, transmit sunlight, and use sunlight, and what makes it possible is hydrogen.”
This vision will enable the sun’s energy (in the form of solar radiation and wind) to be converted into hydrogen through electrolysis, and then transmitted around the world.
As a globally traded commodity, hydrogen can reshape the geopolitical map, thereby ending dependence on fossil fuel exporters and improving the energy security of importers.
IEA added industrial development and skilled work to the potential advantages of hydrogen in its 2019 report. It says that hydrogen is flexible and versatile, being able to act as a fuel between different locations and between different times of the day or year, and as an energy carrier (through storage).
The International Energy Agency’s (IEA) 2019 hydrogen report stated that this could also extend the life of fossil fuels and related infrastructure, such as natural gas pipelines.
“[CCUS [carbon capture, use and storage] is used to reduce the carbon dioxide intensity of fossil fuel hydrogen production, which will allow certain fossil fuel resources to continue to be used.”
In addition, the hydrogen economy can help balance the use of variable renewable energy to generate electricity. Electrolysis can absorb excess power, and when there is little wind or sun, hydrogen can be burned in a gas turbine to ensure that electricity needs are met. IEA explained:
“By producing hydrogen, renewable electricity can be used in applications that chemical fuels can better serve. Low-carbon energy can be provided over long distances and can store electricity to meet weekly or monthly supply-demand imbalances.”
This means that hydrogen can help strengthen and connect today’s largely independent energy systems for heat, electricity, industry, and transportation. This concept is called “sector coupling.”
The technology required to manufacture and use hydrogen may benefit from policy and cost reduction experience that makes renewable energy cheaper.
In view of all these advantages, the IEA report said: “In the future, it may be considered to establish a low-carbon hydrogen economic system covering all fields.” But it adds:
“However, the opportunities for other clean energy technologies have been greatly improved recently, and the most important is the direct use of electricity solutions, which means that the future of hydrogen may be more integrated into a diversified and complementary energy network. In particular. This is because the use of hydrogen in certain end-use sectors faces technical and economic challenges compared to other (low-carbon) competitors.”
Similarly, Bloomberg New Energy Finance senior writer Micheal Liebreich (Micheal Liebreich) wrote in a recent article: “On the surface, [hydrogen] seems to be the answer to every energy question. But he added: “Sadly, hydrogen also shows the same impressive shortcomings.”
The IEA said the challenges include high costs, which make hydrogen uncompetitive today, and over time, the way in which costs will grow is uncertain (see below). It adds:
“Hydrogen poses safety risks, high upfront infrastructure costs, and certain industrial dynamics in the supply and distribution of fossil fuels, especially when used in conjunction with CCUS (Carbon Capture, Use, and Storage). It is not clear how citizens will treat these hydrogen To respond.”
IEA also stated that due to the complexity of the hydrogen supply and value chain, there is a risk of a “chicken and egg” situation, which makes gradual deployment more difficult.
For example, replacing building heating with fossil gas will rely on a large supply of low-carbon hydrogen and appropriately upgraded infrastructure to distribute and safely burn fuel.
Although more and more countries are formulating specific hydrogen strategies, there are uncertainties in government and policy support for hydrogen.
Inefficiency is another major challenge. Compared with many alternative methods, more energy is wasted in each step of hydrogen production and use.
The IEA stated: “Hydrogen-based fuels can use existing infrastructure, with limited changes in the value chain, but at the cost of efficiency losses.”
The Economist magazine called hydrogen “inevitably inefficient,” and the chief engineer of the Institute of Energy Technology wrote in 2018: “According to the current understanding of related technologies, the full implementation of hydrogen is enforced throughout the economy. The strategy used appears to be extremely inefficient.”
The figure below shows why electric vehicles are several times more efficient than hydrogen fuel cell vehicles or vehicles using hydrogen-derived synthetic fuels.
Electric and hydrogen cars? Due to energy loss, the efficiency of battery electric vehicles is at least three times that of hydrogen fuel cell vehicles. pic.twitter.com/Tj662mSmtZ
This is also the case when comparing electric heat pumps with hydrogen boilers, or when considering storing excess electrical energy in the form of hydrogen for later use.
“All energy carriers, including fossil fuels, suffer efficiency losses every time they are produced, converted or used. In the case of hydrogen, these losses will accumulate in different steps in the value chain. Convert electrical energy into hydrogen, transport and store After that, it is converted into electrical energy in the fuel cell, and the energy delivered may be less than 30% of the initial electrical energy input.
“This makes hydrogen more’expensive’ than electricity or natural gas used to produce hydrogen. It also provides a reason to minimize the number of conversions between energy carriers in any value chain. That is, when there are no energy supply restrictions In this case, as long as we pay attention to carbon dioxide emissions, efficiency may depend to a large extent on economics and can be considered at the level of the entire value chain.”
In fact, conventional energy systems based on fossil fuels are already very inefficient. The gasoline energy returned by internal combustion engine vehicles is only 20% of the useful forward motion. Similarly, the average efficiency of coal-fired power plants is only 33%.
This shows that low efficiency is not a fundamental obstacle to the use of hydrogen. Instead, low efficiency may inhibit hydrogen through higher costs and the need for greater energy supplies.
Finally, although cost, efficiency and technical performance are all important factors in solving the hydrogen problem, Thomas Blank, senior director of industry and heavy transportation at the Rocky Mountain Institute, said, “In addition to technical economics, there are also There are some really important drivers.”
“For the EU, this is not necessarily cost-driven in the end, but the security of energy supply. The exposure to [Russian oil and gas imports] Vladimir Putin (Vladimir Putin) is reduced, creating jobs. Drive. At present, those aspects of the hydrogen opportunity are ignored, and they will push things forward.”
Last year, the International Energy Agency (IEA) wrote an important report on the future of hydrogen energy, stating that the hydrogen energy “is currently enjoying unprecedented political and commercial momentum.”
It describes 2019 as a “critical year” for energy carriers and outlines the steady growth of policies and research supporting its use in energy applications.
Influential organizations including the IEA, the Hydrogen Council and BP have all publicized their vision of the importance of the future, while other organizations herald the 2020s as the “Hydrogen Decade.”
The pipeline for “green” hydrogen produced from renewable electricity is rapidly expanding, and has nearly tripled in just five months at the beginning of this year. However, these projects still make a negligible contribution to the global energy system.
Among the 197 parties to the Paris Agreement in 2015, only six countries mentioned “hydrogen” in their first nationally determined contributions to the agreement. However, with the encouragement of the net zero goal, a series of The country has formulated a national hydrogen strategy, and people’s interest is increasing day by day.
A recent review by the German branch of the World Energy Council found that 20 countries have or have begun to adopt such strategies.
The figure below is based on the latest analysis of the board shared with Carbon Brief. It shows that another 33 countries are moving in this direction. The team concluded that by 2025, these strategies will likely cover countries that account for more than 80% of global GDP.
One of the most important announcements is the European Commission’s “Developing a Hydrogen Strategy for Climate-Neutral Europe” in July 2020. One of the ambitious goals is to reach 40 gigawatts (GW) of electrolyzer capacity in Europe by 2030.
According to the consulting firm Wood Mackenzie (Wood Mackenzie), between 2000 and 2019, only 0.25 GW of green hydrogen projects were deployed globally.
At the press conference to launch the strategy, Frans Timmermans, Vice President of the European Commission, described “clean” hydrogen as the “key” of the EU’s “green agreement”, which is to be achieved by 2050 Net zero emissions.
“Most of the energy transition will focus on direct electrification, but in areas such as steel, cement, chemicals, air transportation, heavy transportation, shipping, etc., we need other things.”
Several European countries, including Germany, Portugal and the Netherlands, have strengthened this ambition and released their own hydrogen energy strategies, some of which are in the context of achieving a “green recovery” during the Covid-19 pandemic.
Under pressure to keep pace with European neighbors, British ministers said they will soon announce a “world-leading” hydrogen strategy to help achieve their 2050 net zero goal. State Grid said it will “need” hydrogen to achieve this goal.
British Commerce Secretary Alok Sharma acknowledged the recent “turbulence” of the national hydrogen strategy at a recent environmental audit committee hearing, saying that the government expects to “release its own in the beginning of next year .”
Prime Minister Boris Johnson’s “Green Industrial Revolution” and “Ten Point Plan” mentioned that spending on hydrogen was “up to 500 million pounds (667 million US dollars)”, including the achievement of 5 GW of low-carbon hydrogen in the next ten years. The goal of production capacity.
This is much less than some other European countries. Germany alone stated that it will spend 9 billion euros on clean hydrogen production and exporting the technology overseas, but the same goal is to reach 5GW of domestic production capacity by 2030.
The figure below shows the current and planned hydrogen production capacity worldwide, and shows how Europe is currently leading the way in future production plans.
However, Timmermans said in his speech that although Europe has always been a leader, other countries are catching up, referring to Saudi Arabia’s plan to build a large hydrogen plant powered by 4GW of wind and solar energy. He said: “Hydrogen has become the world’s new energy rock star.”
An energy professional who spoke on Bloomberg recently called the competition in this market and the fight to fund new projects the “Hydrogen War.”
Japan in particular has been exploring hydrogen as an energy source since the 1970s, and its 2017 hydrogen strategy announced plans to establish the first “hydrogen-based society”.
Before the event was postponed due to Covid-19, the Japanese government intends to show its progress at the 2020 Tokyo Olympics, using hydrogen to power the Olympic flame and 100 buses to serve the Olympics. South Korea is another early adopter.
Other countries, including Australia and New Zealand, have issued plans to mobilize their abundant renewable resources and become the main countries exporting green hydrogen to parts of Asia and Europe.
However, in terms of green hydrogen technology, China is regarded as Europe’s biggest competitor, and competition between the two major countries may help lower prices.
China is already the world’s largest hydrogen producer and user, and has been developing hydrogen fuel cells for about 20 years. The former Secretary of Science Vangong, who pioneered the development of the U.S. electric vehicle strategy, said it “should consider establishing a hydrogen society.”
Energy companies such as Shell and BP have also proposed hydrogen plans, promising to deploy low-carbon hydrogen projects as part of their net zero emission targets.
At the same time, the United States, once considered a leader in hydrogen technology, has been lagging behind in recent years.
(Although the map above shows a considerable planned hydrogen capacity, it is distorted by a large-scale project proposed by the energy company SGH2, which states that it plans to have a biomass production facility by 2023.)
The latest report backed by several oil companies and automakers in the country stated that hydrogen “plays a key role in maintaining the U.S.’s global energy leadership”:
“Other countries, such as Germany, Japan, and China, are developing hydrogen infrastructure and investing in the infrastructure of the hydrogen economy. The United States should not be left behind.”
In more than two dozen interviews in this article, people have reached a broad consensus that hydrogen is needed to achieve zero net emissions to avoid dangerous climate change. There is very little consensus on how much hydrogen the world will need and in which sector it will be used.
Like electricity, hydrogen is an “energy carrier” or “energy carrier”. In short, this means that it is a convenient way to store, move and use energy extracted from other sources.
Crucially, the production of electricity and hydrogen can be decarbonized. (See: Which countries are exploring the use of hydrogen?) These zero-carbon energy carriers are critical to achieving net zero carbon.
Although electrification plays a leading role in the pathways identified by the Intergovernmental Panel on Climate Change (IPCC), electrification currently cannot unlock certain areas, such as long-distance transportation.
Dr. David Joffe, head of the carbon budget of the UK Climate Change Advisory Committee, said that this allowed hydrogen to “reach” the “necessary condition” for zero net worth. He told Carbon Brief:
“We believe that you should achieve electrification as much as possible. Where the price is too high or not feasible, this is the role you are looking for hydrogen.”
Unlike electricity, the energy stored in hydrogen is carried by relatively stable chemical bonds, rather than short-lived charges. This means that its energy is easier to store, transport and transform into other molecules for use as fuel or chemical raw materials.
Meredith Annex, Head of Hydrogen and Head of Heating and Cooling at Bloomberg NEF, said: “In some cases, electrification is not appropriate.”
“This may be because you need a fuel molecule to achieve [higher] energy density, chemical reaction or storage durability. Therefore, we believe that hydrogen and low-carbon fuels are the overall elements essential for a zero net economy.”
Although it is expected that hydrogen will play a smaller role than electricity in achieving net zero emissions, its production and use may still need to be greatly expanded from today.
I see that we are back to the debate between hydrogen and electrification. This is the secret of @theCCCuk花式#NetZero computer model: we need *a lot* of both. #ANDnotOR pic.twitter.com/0rrw5b7NqP
The rapid expansion of hydrogen depends on policy decisions, social choices, relative costs, and technical performance in each fuel’s potential application.
There are also uncertainties regarding the future production costs of low-carbon hydrogen and the ease with which fuel will be successfully deployed on a large scale in multiple economic sectors.
Therefore, in the path of simulating how the world (and various countries or regions) reduce emissions to avoid dangerous climate change, hydrogen is used in a wide range.
Carbon Brief analyzed hydrogen use in a series of deep decarbonization scenarios to assess the level of hydrogen use in the overall and specific end-use sectors.
The chart below shows the final energy share provided by hydrogen in the global (top), EU (middle) and UK (bottom) deep decarbonization pathways in 2050.
Each line shows the findings of a single report or organization, and the light blue indicator bar indicates the range of hydrogen shares in different situations (depending on the situation). The center estimate and maximum potential are shown as middle blue and dark blue circles, respectively.
For the global study at the top of the chart, hydrogen meets any requirement between 0% and 30% of final energy in 2050. High-end is the theoretical maximum rather than the actual potential.
The scope of the scenarios covering the EU is similar, and the net zero emission path of the European Commission’s Joint Research Center can reach up to 23% by 2050.
It is worth noting that the UK approach analyzed in this paper includes hydrogen to meet half of the final energy in 2050, which is much higher than the share of EU and global research.
Carbon Brief understands that the Climate Change Committee (CCC) will issue new recommendations on December 9th. The proportion of hydrogen in its scenario will be less than one-fifth to one-third of the total.
Importantly, the amount of hydrogen used in a solution depends on several factors, including the modeler’s assumptions, the level of detail in his model, and the ambition of the modeling path.
Guy Newey, a former British government adviser, argued that after the UK raised its ambitious target of reducing emissions from 80% by 2050 to 100%, “hydrogen is the biggest winner in many ways.” Research shows that there is a correlation between the ambition of the scheme and hydrogen absorption, which provides support for the research.
Relative to the other decarbonization options for each end-use, the lower hydrogen usage rate in any particular model or scenario may reflect outdated assumptions about its cost or technical potential.
Similarly, scenarios that show the widespread use of hydrogen may reflect overly optimistic assumptions about the potential cost reduction that can be achieved in hydrogen production and use, or may see its output grow at an unrealistically rapid rate.
A study conducted by Dr. Sheila Samsatli of the University of Bath and international colleagues showed that: “Hydrogen has historically had a limited role in global energy scenarios.” It adds:
“The results and conclusions obtained from an oversimplified model may be misleading or even wrong. In the case of hydrogen, if no technology is shown in the results, it cannot be determined whether this is due to the inherent shortcomings of the technology or due to the inherent shortcomings of the technology. The model is not enough to represent the advantages of the technology.”
The global research in the above table shows that the lowest hydrogen usage is in the IPCC’s 2018 1.5C Special Report. Such a low absorption rate may partly reflect the age of the modeling literature available at the time, and hydrogen may be considered expensive.
On the basis of “a more comprehensive model of the possible role of hydrogen and bioenergy in the energy transition”, hydrogen is more distinctive in BP’s latest energy outlook.
BP claims that its “net zero” approach is basically in line with the 1.5C scenario. This approach believes that by 2050, the use of hydrogen will reach 5.8 billion joules and meet 15% of the world’s final energy demand.
BP pointed out that the use of hydrogen in this approach is at the “highest end” of the IPCC program, and when emissions reach net zero, the demand is between 15-60 EJ.
The company’s prospects added, “This may reflect that many IPCC programs were prepared before policy and private sector interest in hydrogen increased in the past few years”.
In a report released in March 2020, Bloomberg NEF put forward a stronger hydrogen case. It determines the maximum technological potential of natural gas to meet 30% of the world’s final energy demand in 2050.
As shown in the figure above, in a way to limit the temperature rise to 1.5C higher than the pre-industrial level and the total energy use is much lower, BNEF believes that hydrogen can meet 24% of the world’s final energy demand.
The company’s recent “New Energy Outlook” predicts that by 2050, 800 million tons of hydrogen (MtH2) will be used to meet a quarter of the world’s final energy demand, while keeping the temperature below 2C.
If all electrolytic manufacturing is used, 36,000 terawatt hours (TWh) of electricity will be required. BNEF pointed out: “His electricity is 38% more than the electricity generated in the world today.”
BNEF’s new energy outlook predicts that the use of hydrogen will be distributed among the power sector (30%), industrial sector (30%), transportation (25%) and buildings (15%), as shown in the figure below.
Another recent study is the International Energy Agency (IEA) “Energy Technology Outlook”, released in September 2020. The report believes that by 2050, hydrogen use will be less than 7% of final energy demand, including transportation (44%), industry (28%), electricity (19%) and buildings (9%).
By 2070, while keeping the temperature below 2C, the International Energy Agency (IEA) predicts that hydrogen will meet 13% of final energy demand, and this amount is not evenly distributed among sectors. Hydrogen will meet most of the energy consumption of the shipping and aviation industries, but it will hardly meet the energy needs of buildings, as shown in the right figure below.
The research of Samsatli and colleagues concluded that industrial and heavy transportation provide the greatest opportunities for hydrogen use. It added that if a large-scale hydrogen infrastructure is established to serve these sectors, natural gas can also provide flexibility in other sectors, such as the power sector.
Emma Pinchbeck, CEO of the trading group Energy UK, told Carbon Brief: “The strongest business case for hydrogen is in areas where there are few alternatives.”
Pinchbeck said this may include transportation, heavy industry or heating, but she pointed out: “Electrification will become an important part of solving the heat problem.” Pinchbeck added:
Fundamentally, much of the future value of the energy market will come from electronics and flexibility. Therefore, hydrogen needs to figure out how to adapt to this model…Hydrogen is a very attractive solution, but the challenge is how to make it commercially attractive to accommodate the economic gap that electricity cannot achieve. ”
Hydrogen has been praised by many newspaper editorials and world leaders as the solution to today’s problems, from promoting a “green recovery” after the Covid-19 pandemic to reducing Britain’s reliance on electric car batteries.
The enthusiasm for hydrogen as an energy solution is not new. The first hydrogen-powered internal combustion engine was built in 1807. As early as 1863, there was a debate about the use of hydrogen in electrolyzers to replace coal.
Dr. Tom Brown, an energy system modeler at the Karlsruhe Institute of Technology, outlined this early history in a series of recent Twitter posts. He told Carbon Brief:
“The truth is… If you are smart enough, you can basically do anything with hydrogen. People have basically realized this a long time ago and have been recurring as a theme, but it won’t really be true until you have very low-cost features. Becomes meaningful.”
An early example is a hydrogen electrolyzer of more than 100 megawatts built in the 1920s to power the fertilizer industry and use cheap hydroelectric power in places such as Norway and India.
Despite the current hype, there is nothing new about electrolytic hydrogen. – 100 MW electrolyzers used for fertilizer and heavy water since the late 1920s – Salt caverns that have stored 100 GWh since the 1960s – Today’s 4,500 kilometers of hydrogen pipelines lack a large amount of low-cost electricity. pic.twitter.com/PJh7h49TZ5
As electricity demand in other sectors grows and cheap fossil fuels can be used to produce hydrogen, these early efforts have been eliminated. However, there have been several “hype cycles” since then, and the government has worked hard to get rid of hydrogen.
The term “hydrogen economy” was first proposed in 1970 by the chemist Professor John Bockris, who powered the world by hydrogen produced by solar and nuclear energy.
In the same year, Professor Lawrence Jones, a physicist at the University of Michigan, published a paper entitled “Towards a Liquid Hydrogen Fuel Economy” and concluded that:
“As a pollution-free fuel, in the 21st century, [hydrogen] must be seriously considered as a reasonable substitute for hydrocarbons.”
Soon after the Organization of the Petroleum Exporting Countries (OPEC) imposed an oil embargo on the United States, Japan and Western Europe, the development of commercial hydrogen fuel cells began, which pushed up prices and prompted people to find alternative fuels.
With the lifting of the embargo, the exploitation of new fossil fuels and the drop in oil prices, interest has gradually diminished. The next “false dawn” of the hydrogen economy appeared in the 1990s, when automakers especially invested in this technology.
According to the International Energy Agency, this time, oil prices “have been low for the second half of this century, stifling support that may bring these projects closer to the mainstream”.
In 2003, amid concerns about “peak oil”, US President Bush announced a $1.2 billion hydrogen fuel plan in his State of the Union address, with the aim of “the first car driven by a child born today can be powered by hydrogen.”
However, this kind of hype is relatively short-lived. As shown in the figure below, after reaching its peak in 2008, global government spending on hydrogen began to decline. (Please note that this chart only includes the 30 IEA member states and the European Union. China is not included.)
Gniewomir Flis, energy and climate consultant at think tank Agora Energiewende, told Carbon Brief: “When the hydrogen economy was really not realized in the second half of the 2000s, it was put on hold.”
Climate change has always been the subject of hydrogen discussions, but concerns about oil supply and prices have become major issues, and road vehicles have been regarded as the main target market.
Therefore, in each round of attention, whenever the cost of oil drops or a new supply of fossil fuels is released, the excitement surrounding hydrogen tends to subside.
Professor Ad van Wijk, Professor of Future Energy Systems at Delft University of Technology, told Carbon Brief that the situation is different this time:
“Of course, what you are seeing now is a very different system change, and that is that renewable energy has become very cheap. That is the main driving force.”
The decline in the cost of renewable energy has brought new enthusiasm, because it seems that the prerequisite for the success of hydrogen energy is abundant, low-cost electricity.
Crucially, unless decarbonization reaches every corner of the economy, including the “difficult to decarbonize” sectors such as steel production, shipping and aviation, it is unlikely that the 2015 Paris Agreement’s climate goals will be met.
The International Renewable Energy Agency (IRENA) suggests that hydrogen may become a “missing link” in the global energy system, thereby helping to reduce emissions from all these sectors that are difficult to electrify.
Sunita Satyapal, director of the U.S. Department of Energy’s Office of Hydrogen Energy, told Carbon Brief that the availability of relatively cheap hydrogen means that interest now extends far beyond road transportation. :
She said: “The main benefit of hydrogen is that it can provide value for various applications and help integrate various departments.”
At the same time, Fries pointed out that specialized oil and gas companies have begun to promote hydrogen as an alternative fuel. He said: “They are beginning to realize that they will eventually have to transform into something.”
Some of the world’s largest oil producers, as well as the CEOs of automakers and industrial companies established the Hydrogen Council in 2017 to promote hydrogen development. The attention of institutions such as the International Energy Agency (IEA) and IRENA has also prompted hydrogen to become a concern. Focus.
The “Renewable Hydrogen Alliance” recently launched by key trading agencies shows that the wind and solar industries also support hydrogen, and key trading agencies pledged to help “develop a business model and market that will make renewable hydrogen mainstream.” An analyst specializing in hydrogen economics at consulting firm Wood Mackenzie told Carbon Brief that, in the end, the most important factor is that this technology “is more economically meaningful than ever…”.
According to the IEA, the demand for hydrogen has been steadily increasing for decades and has remained at around 70Mt. Most of them are made from fossil fuels and have high carbon dioxide emissions.
The agency stated that using electricity to meet all of these needs would require specialized production of 3,600 terawatt-hours (TWh)-”more than the EU’s total annual electricity generation.”
Another 45Mt of hydrogen is mixed with other gases for industrial use, such as steel and methanol production.
Today, almost all pure hydrogen is used in applications such as oil refining and fertilizer production, not for driving buildings, trucks, or power generation.
Wood Mackenzie concluded in a report on the state of the industry released in early 2020 that although hydrogen demand has increased by 28% in the past 10 years, this increase is “small compared to many other new technologies.” (The output of wind and solar energy soared during the same period.)
“If the demand for low-carbon hydrogen grows, then the market will grow. Unfortunately, Wood Mackenzie pointed out in the press release.
“Low-carbon hydrogen” is essential here, because although all hydrogen does not produce greenhouse gas emissions when it is burned, the impact of different production methods on the climate varies greatly.
The production of hydrogen is generally known in different colors. For decarbonization purposes, the two most prominent varieties are “green” and “blue”. (IEA avoids the use of these labels because the environmental impact of production can vary greatly within a single color category.)
Green hydrogen is produced through electrolysis. Electrolysis is a process that uses electricity to generate electricity from renewable energy sources to decompose water into hydrogen and oxygen. The label is sometimes misleadingly applied to hydrogen derived from electricity from the grid, which will only be as “renewable” as the grid itself.
On the other hand, blue hydrogen is usually produced by reacting methane gas with steam, and then capturing and storing the resulting CO2 emissions. In steam methane reforming (the most common method), burning fossil gas can both provide fuel for the process and can be used as a feedstock.
For now, most hydrogen is not green or blue, but is made using fossil fuels without any carbon capture. The production methods of natural gas based on coal, lignite and carbon-free capture and storage (CCS) are called “black”, “brown” and “gray”, respectively.
According to the International Energy Agency (IEA), 76% of hydrogen comes from natural gas, while 23% of coal comes from coal-the latter mainly in China-and only 2% comes from electrolysis. Less than 0.7% of the current hydrogen production comes from low-carbon green or blue supply.
In summary, it seems difficult to obtain publicly available unified data on current hydrogen production. This makes it difficult for us to know where the energy we currently produce comes from, and it seems to be a problem for policy making.
In addition, hydrogen production consumes 6% of all natural gas in the world and 2% of all coal each year, and produces 830MtCO2 annually, which is slightly higher than Germany’s annual emissions.
In the short term, gray hydrogen may still be the cheapest and most extensive production route, because there is currently no low-carbon production method that is cost-competitive. (See: “How much does this cost?”)
In order to achieve zero net emissions, hydrogen production needs to be switched from gray to green and blue. The next section will discuss the role of these two variants-”Does’blue’ hydrogen have a place in the net zero future?”
In addition to the basic color, there are several other production methods (some of which are low-carbon) that may lead to future hydrogen demand.
It is also possible to use nuclear energy to drive electrolysis to produce hydrogen. According to the IEA, the hydrogen produced by nuclear energy has “no definite color”, but there are reports that it is “yellow”, “pink” and “purple.”
In addition, heat from nuclear reactors can be applied to hydrogen production by generating steam to improve electrolysis efficiency or steam methane reforming based on fossil gas.
In the long run, the extremely high temperatures of advanced nuclear reactors can directly extract hydrogen from water through thermochemical splitting. These projects are still in the early stages of development.
Professor Robin Grimes, Chief Adviser of Nuclear Science at the British Ministry of Defence, recently wrote a Royal Society paper on “Nuclear Cogeneration”, which uses the heat of reactors in the field of “difficult decarbonization” And the process of generating electricity.
Grimes told Carbon Brief that although large-scale hydrogen production facilities using nuclear energy have not been established anywhere so far, the two industries will benefit from greater integration:
“In fact, nuclear energy is not part of the solution, rather than isolating nuclear energy as something that can only generate base load electricity, because…when electricity is not needed, its heat can be used directly. This is the idea of cogeneration. ”
In the early days of hydrogen research, the use of nuclear energy to produce hydrogen was a popular idea. France, Russia, and the United States are still advocating the use of nuclear energy. These countries already rely heavily on nuclear energy to provide most of the electricity.
A report by the consulting company Lucid Catalyst believes that the amount of hydrogen required to meet international climate targets “far exceeds the hydrogen that can be produced by renewable energy”, so nuclear hydrogen must be used.
The sober report believes that there is a clear path to cheap nuclear energy, and this, combined with cheap high-temperature electrolyzers, will make nuclear-driven production the cheapest way to produce hydrogen, partly due to higher conversion efficiency.
However, according to the International Energy Agency, the solid oxide electrolyzer (SOEC) required to use nuclear energy to produce electrolytic hydrogen is far more expensive than other types. Today, its cost is as high as $5,600 per kilowatt, which is about three to five times that of other electrolyzers.
The agency also pointed out in its hydrogen report that SOEC is “the least developed electrolysis technology” and has yet to be commercialized.
Hydrogen can also be produced using biomass, although the IEA believes that it requires complex processing and lacks sufficient cheap and sustainable biomass, which makes it less attractive than other “low-carbon” technologies. No color is assigned to the hydrogen in the biomass.
The by-product of methane pyrolysis also produces “turquoise” hydrogen, which uses heat to decompose fossil gas into hydrogen and carbon.
This is still only a small-scale niche strategy, but it has attracted the attention of the industry due to the potentially useful applications of its carbon by-products.
If the process is powered by renewable energy or nuclear energy, and the generated carbon is stored, turquoise hydrogen may become a low-emission option.
However, a recent study concluded that, like blue hydrogen, because the gas produced will provide the necessary heat for the process, it still generates a lot of emissions.
There is a lot of debate about the contribution of blue hydrogen in achieving net zero emissions. Some people think it played an important role, while others say that it should be used as a temporary solution at best when green hydrogen is amplified.
At the same time, some activists and scientists believe that blue hydrogen locks countries in the future of fossil fuel use and methane emissions leakage, which means that the use of hydrogen should be completely avoided.
As shown in the figure below, there are currently plans to rapidly expand the green and blue capacity globally. (Please note that not all proposals will be realized. About half of the planned capacity in the chart comes from three main options: Solena’s “Plasma Gasification” proposal in the United States, marked as “Other” in the chart; H21 Blue Hydrogen Solution The United States and the United Kingdom; and the Asian Renewable Energy Center planned to be established in Australia.)
The project pipeline in the table above roughly reflects the production method split envisaged in the net scenario of BP’s energy outlook of zero, where 16% of the final energy consumption in 2050 will come from hydrogen – half of green and blue.
The oil giants are not alone in portraying the future of blue hydrogen. The UK’s “Climate Change Commission” (CCC)’s indicative path to net zero emissions relies mainly on blue hydrogen, although Carbon Brief understands that the latest guidance expected to be released in December will point to a greater share of green.
Those who support blue hydrogen believe that net zero is necessary because it can be used immediately and can make better use of renewable power resources in the short term. It can also be integrated into existing fossil gas infrastructure.
Spencer Dale, chief economist of BP Group, stated at the energy outlook conference that only focusing on green hydrogen will “limit the growth rate of the hydrogen economy.”
A report by Ralf Dickel, an energy trade expert at the Oxford Energy Institute, concluded that excessive reliance on green hydrogen would mean “cannibalizing the success of renewable electricity in the power sector…what is this? What? From now on, blue hydrogen can play a role in decarbonizing non-power sectors.”
Governments have shown their support for blue hydrogen at least in the short term. Julian Critclow, director-general of energy transition and clean growth at the Department of Business, Energy and Industrial Strategy (BEIS), said it “played a role in the middle period.”
In his speech on the European Commission’s hydrogen strategy, Vice Chairman Timmermans emphasized that green hydrogen will be given priority in Europe, but will temporarily support CCS production to “help us replace dirty hydrogen”.
The European Environment Agency described the European Commission’s support for blue hydrogen as a “gift from the fossil fuel industry”.
Although the committee’s own analysis supports Timmerman’s comments, it also mentions one of the key issues of retaining blue hydrogen:
“In the future of decarbonization, hydrogen produced by decarbonization of electrolysis and electrolysis is the first choice, including’green’ hydrogen obtained from renewable energy sources. As long as the inherent limitations of CCS are lifted, natural gas steam reforming is combined with CCS.” Blue “hydrogen may also play a role.”
The International Renewable Energy Agency (IRENA) has emphasized these “inherent constraints”. In its hydrogen energy report, the agency pointed out that CCS technology has not yet reached its potential and is still “off track in both power generation and industry.” .
The report also pointed out that since CCS can usually only reduce CO2 emissions by 80-90%, blue hydrogen is “not inherently carbon-free”.
According to the IEA, higher carbon capture rates may exceed 90%, especially if an alternative hydrogen production method called autothermal reforming is used instead of the more traditional steam methane reforming.
However, due to emissions from the methane production process, even at a 100% capture rate, blue hydrogen will not be zero carbon. Thomas Blank of the Rocky Mountain Institute told Carbon Brief:
“In the initial discussions surrounding hydrogen, I think people have assumed that blue hydrogen is zero-carbon, just like there is a biofuel hypothesis, and it is not a zero-carbon fuel.”
He pointed out that although a higher carbon capture rate can be achieved, it will make the process more expensive. He said: “I think policy makers have begun to realize this reality.”
The net zero report of the British Energy Systems Catapult pointed out that although “speculative innovative measures” resulted in a carbon capture rate of 99%, blue hydrogen would be “extremely attractive”, and any other factor could be used. Effectively exclude:
“Without speculative innovative measures, methane reforming with a methane conversion rate of only 95% has too high a carbon content to achieve net zero emissions.”
The IEA chart below shows the emissions still produced by CCS using fossil fuels compared to renewable energy or nuclear-powered electrolysis.
However, this chart only shows the CO2 intensity. It does not take into account the upstream methane emissions caused by the leakage of natural gas production and distribution systems. Even if CCS can capture 100% of the CO2 released by the process, it may not necessarily be avoided.
Gniewomir Flis of Agora Energiewende told Carbon Brief that he was “very concerned” about these emissions when considering blue hydrogen.
He said: “As far as I know, neither the IEA nor other agencies can reliably explain these upstream emissions.”
I often hear that blue hydrogen (natural gas steam reforming + CCS) releases as little carbon dioxide as green hydrogen (electrolysis). However, you must include the upstream emissions from natural gas production, and then the emissions of blue hydrogen will increase significantly. https://t.co/D0jB5too5g
The Pembina Institute think tank emphasized in a report that upstream emissions may significantly change the impact of blue hydrogen on the climate. Its focus is Canada, which is planning to expand blue hydrogen production in the fossil fuel-rich province of Alberta.
It estimates the range of blue hydrogen to be 2.3-4.1kg CO2e per kilogram, which the report said reflects changes in methane emissions from the upper reaches of the country.
CCC’s net zero technical report in the United Kingdom stated that fossil gas can produce low-carbon hydrogen, with an emission of about 0.3 kilograms of carbon dioxide per kilogram, and a capture rate of 95%. In contrast, the IEA estimates 0.9kg CO2 per kilogram of hydrogen, with a capture rate of 90%, as shown in the figure above.
However, if the upstream emissions from fossil gas production are included, the committee stated that the emissions per kilogram of hydrogen are about 0.7-2.5 kg CO2e, with a capture rate of 95%.
To illustrate this point, BNEF’s “New Energy Scenario” envisages that 800 million tons of hydrogen will be used globally by 2050. If all of these were made from blue hydrogen with a 95% capture rate, then this would be equivalent to 60 to 2 billion tons of carbon dioxide.
Dr. David Joffe, head of CCC’s carbon budget, told Carbon Brief that there is still some room for blue hydrogen within the UK’s net-zero goal, but not much is needed to meet all the potential needs of large-scale sectors, such as heating and transportation. He said:
“There is no specific threshold that can never be exceeded… [but] when you get close to zero net, these residual emissions do start to become important.”
Finally, there is evidence that hydrogen released into the atmosphere from infrastructure leaks may directly affect climate change.
A report prepared for the British government stated that although hydrogen itself is not a pollutant, it can act as an “indirect greenhouse gas” by accelerating the accumulation of methane and ozone in the lower atmosphere.
According to the report, a model study evaluating the global warming potential of hydrogen yielded a value of 4.3. The conclusion is that although the impact of hydrogen emissions on the climate may be small, this issue deserves further study.
The role that green and blue hydrogen will play in economic decarbonization depends largely on the cost of both.
These forms of “low-carbon” hydrogen must not only compete with each other, but also obtain hydrogen from fossil fuels without the additional cost of CCS, and also need to compete with other alternative energy solutions (from electric vehicles to biofuels).
Although the cost of hydrogen production is an important component, it is not the only factor that affects the final price for consumers.
Transportation costs can be an important factor, especially if hydrogen is imported from overseas, and the cost of distributing hydrogen within a country. There are also profits collected by the company, which are added to the final price.
The IEA’s uncertainty on this subject is straightforward, noting that “it is not clear about the relative costs of producing hydrogen from different sources in different regions and how they will compete in the future”.
According to the current situation, gray hydrogen is the cheapest option, at a cost of about US$1/kg-if it comes from Middle Eastern natural gas, it can even be as high as US$3/kg in some regions. For both China and India, which import most of their natural gas, coal-to-hydrogen is often the cheapest option.
According to the International Energy Agency, if CCS is used to turn the lowest cost gray hydrogen blue into blue, the cost will be about US$1.5/kg.
In contrast, the agency pointed out that the use of solar or land-based wind energy to produce green hydrogen is usually between US$2.5 and US$6 per kilogram. (Other estimates are lower, see below.)
Although hydrogen from certain renewable sources may already be cost-competitive in certain applications, there is still a long way to go before fossil fuel-derived equivalents are eliminated.
Nevertheless, people are generally optimistic about the competitiveness of green hydrogen, and the decline in the cost of renewable energy is generally considered to be the main driving factor.
The table below shows that under BNEF’s “optimistic” assumption, by 2030, the cheapest renewable hydrogen may even exceed the cheapest low-carbon hydrogen in natural gas.
For many people, reports of record-low solar prices from Saudi Arabia to Portugal in recent months support the view that despite its inefficiency and possible high transportation costs, imports of green hydrogen may still become the world’s A cost-effective solution in many places.
Another key factor is the introduction of electrolyzers for the production of green hydrogen. Prices have fallen by 60% in the past decade. According to the European Commission, prices are “expected to be halved by 2030 compared to today’s economies of scale”.
Post time: Mar-01-2021