40% of global greenhouse gas emissions come from “hard-to-abate” industry sectors like industrial processing and transport. Electrification won’t be enough. They also need hydrogen, argue Patrick Molloy and Leeann Baronett at Rocky Mountain Institute. Hydrogen production is already well established and growing. But it’s mainly for the chemical industry, which never meant it to be “green”: sure enough, only 4% of current hydrogen production is made by electrolysis powered by renewables. The rest is created using fossil fuels. Ramping up green hydrogen is essential if it’s to meet its full transition potential, as growing demand for alternative energy will see hydrogen production quadruple by 2050, say the authors. Though green hydrogen is still expensive and hard to scale, it’s the same criticism that was once aimed at wind and solar, criticism now shown to be short-sighted.
Hydrogen is the new kid on the block of low-carbon alternatives, with applications in mobility, industrial processing, and heavy transport. It can also be used to provide electricity and heat, and can be blended with natural gas to help decarbonise existing natural gas grids. But even with these opportunities, across the globe—from corporate offices to industry roadshows—one hears a frequent refrain: it is too expensive and it won’t scale. (Interestingly enough, this is the same reputation solar PV had a decade ago.)
As misconceptions about hydrogen abound, there is an opportunity to dispel some of the common myths about this emerging technology.
The transition will be a blend of alternative fuels and electrification
When it comes to technology change, most people think of it as a roulette game where the winner takes all: AC versus DC, QWERTY versus Dvorak, VHS versus Beta. The debate around green options for low-carbon mobility, as well as freight, heavy industry, and materials movement, is no different. The general thinking is that the payoff will come from either electrification or innovative fuels, but not both. This is not an either-or situation. Instead, it’s like being stranded on a desert island and choosing between water or food when the only survivable option is to find both. The ultimate solution for low-carbon transport will most likely be a blend of electricity-based and fuel-based options.
Among the fuel-based options, hydrogen dominates the conversation. As generally happens when you’re popular, the haters are expressing doubt over the development of hydrogen resources, fearing that it competes with electrification and battery technology, but this concern doesn’t reflect reality. While electrification and fuels, like hydrogen, both come with their own set of challenges, they both have important roles to play. When electricity from low-carbon generation is substituted for fossil fuels, we can achieve significant reductions in CO2 emissions. With its zero-carbon potential and the role it can play in increasing demand for renewable energy, hydrogen has an important role in our energy transition and is a key complement to electrification.
Hydrogen: already in high demand and growing
New interest in hydrogen has come from the mobility, freight, shipping, power, and industrial processing sectors as they strive to move toward a decarbonised future. There is, however, a large pre-existing demand linked to refining and ammonia production and as a feedstock for industrial chemical processes. The development of the hydrogen market reflects the potential for distributed production and the need for flexibility in our transport mix. For example, hydrogen fuel cell buses typically have a range of approximately 500 km, versus 200 km for electric buses. With this range, hydrogen has both the potential to decarbonise rural transport and to offer a solution for uninterrupted services.
Hydrogen production has increased from around 40 million tons in 2005 to approximately 60 million tons today. In 2017, the global hydrogen production market was estimated at $103 billion and is expected to reach $207 billion by 2026, suggesting a compound annual growth rate of 8.1 percent or a market of approximately 121 million metric tons. Given these growth expectations, the Energy Transition Commission (ETC) suggests that by 2050 the market could be in the region of 425–650 million tons per year.
Hard-to-abate industrial sectors
Whichever direction the hydrogen market develops in the next decade, the mounting pressure on hard-to-abate industrial sectors to align toward a 1.5-degree science-based pathway implies the need to take a hard look at what proportion of industrial emissions relate to the on-site and off-site movement of materials and products. For example, on average, around 60 percent of energy used on an open-pit mine relates to on-site materials movement. Industrial emissions produced on site account for 28 percent of global emissions. An additional 16 percent take place in off-site materials movement, more commonly known as freight transport. If hydrogen is to be part of the solution, there will be far more than the current 60 million tons per year of global demand for this commodity.
Green Hydrogen: electrolysis powered by renewables
There are four major sources for commercial production of hydrogen, three of which require fossil fuels: steam methane reformation (SMR), oxidation, and gasification. The fourth source is electrolysis, which separates water into its constituent elements (hydrogen and oxygen) using electricity. When that electricity is produced through renewable resources you can have zero carbon green hydrogen. This is the only non-fossil fuel means of hydrogen production. The SMR process, which emits CO2, requires substantial heat to chemically separate the hydrogen from the methane molecules. When the emissions of that process are not captured, it is referred to as grey hydrogen. When carbon capture and storage (or carbon capture, utilization, and storage) is attached to a facility, it is referred to as blue hydrogen. In addition to SMR, hydrogen can also be synthesised from oil via partial oxidation, or from coal via gasification.
…but only 4% of global hydrogen production is “green”
CO2 emitted as a byproduct of SMR hydrogen production accounts for approximately 6 percent of GHG emissions from petroleum refineries in the United States, and up to 25 percent of the GHG emissions from an individual refinery. By source, hydrogen via natural gas accounts for 48 percent of global production, while oil-based production accounts for approximately 30 percent, and coal accounts for 18 percent. Green hydrogen, produced through the electrolysis process using renewable energy, currently accounts for only 4 percent of global production.
The vast majority of hydrogen production today falls into the category of grey hydrogen, as current production relies on fossil fuels and separates the hydrogen and carbon elements. Carbon capture technologies can reduce the carbon emissions by 71–92 percent but the technology is still in a relatively nascent stage. There are also concerns around the storage space necessary for captured carbon. The current movement is toward scaling green hydrogen development and moving away from SMR-based hydrogen. This transition has the benefit of adding demand for a more rapid renewable energy rollout in some of the better renewable energy regions across the United States.
Decarbonising industrial value chains
Over the past several years, we have seen a growing focus on the need to support the development of the renewables sector through the sustainable extraction of copper, lithium, aluminum, cobalt, nickel, and other minerals. These are critical minerals in the development of everything from transmission and distribution wiring to solar panels, wind turbines, and battery storage. To entirely decarbonise them requires a focus on extractive activities, the transportation of materials, and mineral processing and purification. Hydrogen can play a dynamic role in this effort in many applications. For example, it can be used to provide a scalable resource to power on-site haul trucks or provide resilient power generation for mine processes, either from fuel cells or through turbines. Hydrogen can also be used as part of the heating process through either combustion or by use of high-heat-emitting fuel cells. In mineral processing, hydrogen can replace coking coal in the steelmaking process to reduce iron ore.
Using curtailed solar/wind to make green hydrogen
It can also run on curtailed renewable energy; building an electrolyzer attached to a renewable generation and battery combination can give you greater capacity to capture peak generation and shift it to peak consumption hours. The conversion of curtailed power into hydrogen at certain times during the day offers the prospect of either using the hydrogen later to provide a callable power resource, or using existing natural gas infrastructure as a means of getting more renewable energy to end users.
This is a menu of options rather than a decisive position as differing market conditions, access, or end users will change the potential solutions that hydrogen can provide in renewable energy development. These additional options help reinforce the need for large-scale renewable rollout and provide an additional strand by which renewables can reach end users.
An Inevitable Truth: This Is Going to Happen
Hard-to-abate industry sectors constitute 40 percent of global greenhouse gas emissions. These sectors need a comprehensive approach to decarbonisation and they need it now. They need electrification but they also need clean molecular energy. These are not mutually exclusive efforts but can, when structured correctly, work in coordination to facilitate the rapid change that is called for. The pathway to scaling up green hydrogen will require substantial buildout of our renewable energy resources across the globe and the understanding that there are still battles to be fought to meet these targets.
The ETC’s Mission Possible report, Shell’s Sky Scenario, and the International Energy Association’s below 2 degrees Celsius scenario all show well-developed pathways to decarbonising the hard-to-abate sectors, and those pathways all require substantial global hydrogen growth. Whether it is in trucking with Nikola’s recent launch, or in industrial process innovations like green aluminum or green steel, there is one thing that nearly all major energy mix studies have shown: we will need more hydrogen in our energy mix to keep global warming below 1.5 degrees.
Patrick Molloy is a Senior Associate, Industry And Heavy Transport, at Rocky Mountain Institute
Leeann Baronett is a Marketing Manager, Industry And Heavy Transport, at Rocky Mountain Institute
This article is published with permission. Copyright 2019, Rocky Mountain Institute.
At this moment I don’t have a link to an English website that fully explains it all why the emphasis on hydrogen would be wrong. So let me jot it down in bullet points below and I hope you will be interested the hear more.
– electrolysis of water will always lose efficiency. This is due to the second law of thermodynamics, which states that any energy which is used, is always degraded (i.e. exergy decreases, enthalpy increases)
What this means in practice is that renewable electricity should be used as much in the form of electricity (electricity has the highest exergy of any form of energy). E.g. are electricity use to drive heatpumps, cars and even heavy transport. Any transformation (degrading of) electricity into hydrogen to then turn it into electricity again (by a fuel cell in cars or trucks) or even worse for heat is vastly less efficient. E.g. heatpumps have efficiencies of up to 500%, hydrogen max 100%.
A major point of Amory Lovins has always been that efficiency have been (and will be/should be) the biggest driver towards a more sustainable world. I wonder how the conversion of electricity to hydrogen for every application fits in with this insight.
– green hydrogen is only renewable when made from renewable electricity. At this moment very few grids are 100% powered renewable. And this is where another ‘myth’ of hydrogen comes in: to convert curtailed electricity production to hydrogen. This shows lack of understanding how many grids work and the economics of an electrolyser (or any industrial equipment).
First of all, there are many contenders to deliver flexibility to use otherwise curtailed electricity production. E.g. batteries in EVs, heat pumps (in houses or industrial), industrial processes such as cooling and heating (already used in this fashion today). This is called demand side energy management. Hydorgen would have to compete with these options, and it doesn’t have the best of papers (again inefficient, extra infrastructure needed..)
Second, major grids today only run 30% renewable electricity. The level of curtailment is very low and yes it might become higher in the future. But the lost value of curtailment does not necessarily weigh up against the extra costs a hydrogen infrastructure (if it already wins from other demand side management options). But even worse….
Thirdly, any investor in an electrolyser for hydrogen is not going to let it run only for the around 100 hours of otherwise curtailed electricity. Any operator is going to run it for the most hours a year (say 8000) it can, as it is producing a commodity. The economics of commodities dictates producing as much volume as possible. This means hydrogen production is going to create extra demand for electricity, also in hours that are not renewable. The remedy being worse than the cause every year before 2030. Only after 2030 / 2035 can we expect grids to run on 70+% on renewable electricity.
So yes in the end decarbonization requires hydrogen production to be made from electrolysis. However, one should time be careful about its timing and the use. Hydrogen being used as feedstock (in industry) needs this, but for other options where good electrification options exists we should avoid it as much as possible.
Daniel Williams says
I am not going to read your comment because I don’t have the time or patience. However, please understand that hydrogen can indeed be produced for less than the cost of electricity from the same resource. This is because in order to correctly price the resource, issues such as infrastructure and storage must also be accounted for. In this way, a variable electricity price is used. Rather than build a 1 GW HVDC cable (no HVDC has been built in the US since 1998), much cheaper electricity infrastructure is used, and integrated accordingly. This supports 500 MW of the resource. The remaining 500 MW is sent via pipeline and stored in salt cavern storage (like natural gas) or delivered to an industrial user; at much lower cost.
In Europe, the industry association for electric utilities representing 3,500 electric utilities has stated that only 60% (maximum) of the entire EU energy system can be decarbonised with electricity. This leaves 40% of the energy system. Biogas is 2% (200 TWh) maximum. So we can either wait until the size of the electricity grid triples (using RES only), and electrolyse the remaining 1/3rd (which is likely to be well after the 2050 deadline) – or we can use methane, in combination with CCS. Pre-combustion carbon capture requires hydrogen pipelines as well as CO2 pipelines. The other option is pyrolysis or the Hazer process; which could end up being cheaper. However we need the hydrogen pipelines anyway – and we need the CO2 pipelines anyway because we have process emissions.
So its your choice. We can still produce hydrogen cheaper than electricity, though.
Wow you must be extremely busy and / or really important person for not taking the time to read the comment. I am flattered by your reaction though. /scarcasmoff
If you had read my comment, it says we should be careful for too much emphasis on hydrogen made from renewables before 2030 as it could have adverse effects.
Hope this comment is short enough.
Bonus part: anyone who says definite facts about 2050 should take lessons in humbleness. It wouldn’t be the first time to wrongly predict the future, clouded by todays’ knowledge. Yes you’re right that the outlooks currently are about 60% electrification in 2050. But let’s get to 2030 first shall we?
Roger Arnold says
Hydrogen from steam reforming of methane or other fossil fuels can be just as “green” as hydrogen produced from electrolysis using renewable energy. It’s just necessary that the CO2 off stream from reforming be sequestered.
No it can’t by definition not be just as green…there is extra energy (electricity) involved in carbon capture, compression and storage. Order of magnitude is about 20% electricity of a power plant is necessary for this process. For an easier energy transition higher efficiences will have positive 2nd order effects (just as inefficiencies will negative 2nd order effects) Aside for the lock-in effect created from turning too much to hydrogen based activities. My main point that hydrogen now is 10 years too early still stands.
Roger Arnold says
Bart, your figure of 20% of power plant output for CCS is in agreement with IPCC estimates I’ve seen (and have no reason to question) for post-combustion CCS from the flue gases of conventional coal-fired power plants. That’s not what anyone here is talking about.
The article from Mr. Malloy at RMI was about the need for hydrogen to replace natural gas or other hydrocarbon fuels in “hard to abate” sectors, and lamenting that only 4% of that hydrogen was “green”. Your previous comment points out — again correctly — that electrolysis of water to produce hydrogen has a high energy cost, and that instead of substituting hydrogen for hydrocarbons in “hard to abate” applications, it’s better (i.e, more efficient and generally cleaner) to redesign / upgrade the processes involved to use electricity directly.
You won’t get much of an argument from me about that either, beyond the caveat that direct electrification isn’t always feasible. My previous comment referred to Malloy’s lament that only 4% of hydrogen produced today is “green”. I said that hydrogen produced by steam reforming of fossil fuels can be “just as green” as hydrogen produced by electrolysis of water using surplus renewable energy. It just required that the CO2 offstream from the reforming process be sequestered, not vented to the atmosphere.
I was being generous. I was taking direct carbon emissions per unit of hydrogen produced as the measure of “greenness”. Zero equals zero. If instead you measure it by energy consumed per unit of hydrogen produced, then steam reforming with carbon sequestration wins hands down. It’s conservatively in the range of 5 to 10 times “greener”.
In producing hydrogen by steam reforming of hydrocarbons, the chemical potential energy that goes into the hydrogen produced is all available “for free” in the hydrocarbon feedstock. Yes, it does take energy to produce and transport that hydrocarbon feedstock, and it does take energy to transport and sequester the CO2 offstream from the reforming process. Estimates for how much that energy is vary, and depend on differing assumptions that analysts make, and differences in how they account for energy consumed in the support systems involved. But the worst case estimate for “energy returned on energy invested” in oil and gas production that I find credible is about 5:1. Reduce that to 4:1 for the energy consumed in carbon sequestration. Say 4 kWh thermal in the hydrogen produced from 1 kWh electrical.
By contrast, “green” hydrogen from electrolysis using renewable energy requires at least 1.6 kWh electrical for every kWh thermal of produced hydrogen. That’s an EROEI of 1:1.6 for electrolytic hydrogen, vs. 4:1 for hydrogen from fossil fuels. About a 7:1 advantage for the latter, and that’s giving a free pass to the former for the mineral resources, land, and energy needed to build the associated renewable energy capacity.
One has to strongly oppose the idea of CCS to make electrolytic hydrogen look greener.
Hi Roger, thanks for your reply. I actually think that we understand each other quite well. I am not opposed to CCS for principle reasons, I am just afraid that giving in as one of the first options creates a lock in effect. And thereby releaving the pressure on source solutions. I notice that politicians have a hard time putting hydrogen in the right order / perspective of things and that is why I am critical of jubilant stories on hydrogen.
Patrick Joseph Maloney says
I wonder how this article failed to once mention hydrogen generated by nuclear?
Dear Patrick, please learn more about demand side energy management. There is no such ‘physical thing’ as hydrogen generation from nuclear. Yes, hydrogen can be generated from electrical load (electrolysis), but the source of the electricity does in so far not matter (electricity is electricity). Well, yes it does matter in so far as particular load generators (e.g. nuclear, renewables) have specific profiles. But these generation profiles (say sunny during the day) can be matched by many more different loads. E.g. electric vehicles, heat pumps, water heaters, industrial freezers, electric arc furnaces…. Don’t chase the hydrogen dream as a goal in itself, but apply it in dose and time when it is due best.
Patrick Joseph Maloney says
I seems to me that much of the “renewable” prospects for future energy potential depend on certain things happening and certain technical advancements being made by certain dates in the future.
Energy generation enthusiasms seem to have the common flaw of being wildly aspirational
Fair enough…..in the future wind turbines may be able to generate electricity outside their present restrictive envelope and solar panels may be able to work at night (at what level of efficiency, I wonder?)
Given that, I fail to see why the possible generation of hydrogen from the direct heat of high temperature molten salt reactors cannot get a mention?
Perhaps its the form of energy that , as Oscar Wilde said in a different context “dare not speak it’s name”?
Dear Patrick, why on earth would one want to make hydrogen from high temperature molten salt? The second law of thermodynamics states that with any conversion of energy from one form to another you lose efficiency (Gibbs free energy, or entrophy). The molten salt is already a form of storage for energy. Why transform it to another form of storage in the form of hydrogen? I am afraid you see hydrogen as an end in itself, not as a means.
And yes renewable electricity from wind and solar will likely not be able to cover all energy use. All the more reason to be as efficient as possible (see 2nd law of thermodynamics).
Roger Arnold says
The salt in a molten salt nuclear reactor is not for energy storage. It’s the heat exchange medium for the reactor. It’s hot enough that it can be used to drive a thermochemical decomposition cycle to produce hydrogen. That’s potentially more efficient than using it to first produce electricity and then using the electricity to produce hydrogen through electrolysis.
Patrik was writing about “hard to abate” sectors — those like long distance aviation that don’t lend themselves to electrification. For those, the most viable carbon-neutral solution is synthetic fuels. Synthetic aviation fuel can be made from CO2 and hydrogen. If molten salt nuclear reactors prove to be economically feasible, then using some of them to produce hydrogen for synthetic fuels would be a good solution for “hard to abate” sectors.
I must say, however, that I’m surprised to see someone who is with RMI speaking up for that approach. I thought nuclear power of any sort was anathema at RMI. Has hell frozen over while the earth has warmed?
Roger Arnold says
Oops, confusion of names. Patrick Joseph Maloney != Patrick Malloy. My bad. Hell may now continue its normal burning. The earth may be joining it soon.