The Forum Network is a space for experts and thought leaders—from around the world and all parts of society— to discuss and develop solutions now and for the future. It aims to foster the fruitful exchange of expertise and perspectives across fields, and opinions expressed do not necessarily represent the views of the OECD.
The climate science is clear: we need to decarbonise the global economy by mid-century at the latest. A well-designed energy transition is integral to this, with innovative solutions like hydrogen providing an important piece of the puzzle.
The Intergovernmental Panel on Climate Change (IPCC) recognises that hydrogen will be vital in this shift, however they currently estimate it will represent just 2.1% of total energy consumption by 2050. Despite this limited role, hydrogen has quickly taken hold of the global energy transition agenda, overshadowing many readily scalable solutions we should be deploying today.
Hydrogen has morphed from a targeted solution to a 'silver bullet' for the energy transition. This is a far cry from the IPCC's 2050 forecast based on the economic and technical barriers of hydrogen.
The United Kingdom for example, is in the midst of a fierce debate about the wide-scale use of hydrogen for decarbonising home heating. Norway and Germany are detailing a plan to build hydrogen-fuelled power plants and a hydrogen pipeline between the two countries. South Africa, Egypt and Morocco are eying the development of a hydrogen export market. The United States, Mexico and Canada are planning to build a North American clean hydrogen market; meanwhile, Japan is promoting a clean hydrogen society and planning to cross reference the cost of hydrogen with liquified natural gas.
Hydrogen has morphed from a targeted solution to a "silver bullet" for the energy transition. This is a far cry from the IPCC's 2050 forecast based on the economic and technical barriers of hydrogen.
As independent and voluntary experts, the Hydrogen Science Coalition (HSC) has defined five principles to bring science to the forefront of hydrogen decisions. Here are three that are relevant to what we expect to see of hydrogen in 2023.
The only near zero-emission hydrogen is renewable hydrogen
It's important to highlight that hydrogen is not an energy source but an energy carrier, which can be produced in different ways to store energy a bit like a battery. In 2021, 99% of the world's hydrogen was produced from natural gas and coal, emitting over 900 Mt of greenhouse gases (GHGs) in the process.
As pressure builds to deliver the huge quantities of hydrogen promised in new government strategies, the question of how to rapidly scale up production has quickly turned into a debate on what can count as "clean hydrogen".
Hydrogen made from fossil methane is often classified as "grey" hydrogen. This becomes "blue" hydrogen if CO2 released during manufacture is captured and sequestered. "Green" hydrogen, which better aligns with climate goals, refers to hydrogen made by the electrolysis of water using renewable electricity. The term "clean" hydrogen is often used to refer to low-carbon hydrogen, produced using fossil fuels coupled with Carbon Capture and Storage (CCS); that is, blue hydrogen. Without CCS—a technology which is economically unproven at large scales— burning fossil-based hydrogen in fact pollutes more than using natural gas by itself. (See our explainer on ways to produce hydrogen.)
If the objective of ramping up clean hydrogen production is to avoid exacerbating the climate crisis, then any definition of it must be compatible with the Paris Agreement’s 2050 net-zero goal.
To provide clarity, we have proposed a Clean Hydrogen Definition. It meets the same GHG emissions intensity levels as the Green Hydrogen Standard, but accounts for all GHG emissions in the production of hydrogen and its supply chain (see Figure 1). This amounts to 1 kilogramme (kg) of carbon dioxide equivalent (CO2e) emitted per kilogramme of hydrogen produced. By contrast, fossil-based hydrogen produced from natural gas today emits around 10 kg of CO2 per kg of hydrogen.
Figure 1: Blue Hydrogen Production Emissions
Source: The Hydrogen Science Coalition
Even with current best-practice CCS projects, such as the Quest project in Canada which is capturing around 45% of CO2 emissions, our calculations show they still produce around 6.3 kg CO2. This does not include unintentional methane leaks (or "fugitive emissions") from the natural gas supply chain, which make the effective CO2 emissions considerably worse.
The fossil-based hydrogen industry will find it challenging to meet a 1 kg CO2e/kg H2 emissions intensity level on a life cycle basis, because of the source of natural gas (very few areas produce natural gas clean enough due to high fugitive methane emissions) and the ineffectiveness of CO2 capture by CCS technology. If it doesn’t meet this level of emissions, fossil-based hydrogen combined with CCS is unlikely to mitigate climate change in any application.
Renewable hydrogen should be prioritised to decarbonise existing fossil-based hydrogen
Fossil-based hydrogen already accounts for around 2% of the world’s GHGs—roughly the same as the global aviation sector. What's more, to decarbonise the existing fossil-based hydrogen sector using green hydrogen, we would need almost three times the amount of wind and solar electricity that the world produced in 2019.
Before focusing on new markets for existing limited renewable hydrogen supplies, we must address the already polluting fossil-based hydrogen market today.
Some governments have already cottoned on. Countries like India aim to be world leaders in decarbonising their heavily polluting industrial use of fossil-based hydrogen with renewable hydrogen. Others like Morocco are looking to follow closely behind.
Hydrogen shouldn't delay accelerating the deployment of existing electrification and energy efficiency solutions
Where electrification or energy efficiency solutions already exist, hydrogen is not a cost-effective large-scale solution. Research shows this is the case in sectors like domestic heating and land transport.
In fact, the HSC estimated that heating buildings with boilers using renewable hydrogen would take six times more renewable electricity than using electric heat pumps. Figure 2 shows this comparison in the context of the United Kingdom’s domestic heating.
Figure 2: Heating the UK with Heat Pumps or Green Hydrogen
Source: The Hydrogen Science Coalition. Colours indicate types of energy used (renewable electricity, green hydrogen or heat); purple boxes containing wind turbines are scaled to show the required area of wind farms.
Even if affordable hydrogen solutions are ultimately developed, it shouldn’t be at the expense of rolling out efficient electrification that already works. This includes heat pumps and electric vehicles.
A future with hydrogen needs a realistic and well thought out energy strategy
Scaling up truly clean hydrogen is an important, yet long, path forward.
There remains an important risk of overestimating hydrogen’s potential. According to a recent study by the Potsdam Institute, the accelerated deployment of alternatives to hydrogen offers the best hedge against the risk that hydrogen fails to meet lofty expectations.
Policymakers must avoid getting caught up in the hype, and not let hydrogen distract from prioritising more structural actions to decarbonise the economy.
Policymakers must avoid getting caught up in the hype, and not let hydrogen distract from prioritising more structural actions to decarbonise the economy. This includes reviewing building codes and retrofitting policies, direct electrification, adopting ecofiscal and regulatory measures, and financing a transition towards more circular industrial models.
What is needed today is straightforward: ensure we scale up truly “clean” hydrogen; prioritise decarbonising today's polluting fossil-based hydrogen; and roll out existing efficiency and decarbonised electrification solutions before making bets on a future hydrogen economy.
If we do this, we have a chance at ensuring hydrogen plays its valuable role in the energy transition without derailing our progress towards net zero by 2050.
To learn more, check out the IEA's Global Hydrogen Review 2022 and don't miss the forthcoming OECD report Regional Industrial Transitions to Climate Neutrality (15 Feb. 2023), which identifies the manufacturing activities that are particularly difficult to decarbonise and the transformations they require.
And read also on the OECD Forum Network: Solar heat is an essential asset for our cities' and territories' energy transition, by Hugues Defréville Co-founder & President, Newheat