What Is Hydrogen Used For? Today's Uses and Real Limits
What is hydrogen used for? Today almost all of it is used in oil refining and industry, mainly to clean up fuels and to make ammonia for fertilizer, with smaller amounts going into chemicals such as methanol and into steelmaking. Newer uses such as trucks, power plants and synthetic fuels get most of the headlines, but they still use only a very small share of the hydrogen the world produces.
This guide walks through each use in plain English, shows how much hydrogen some common products need, and is honest about where hydrogen makes sense and where it doesn't.
What is hydrogen used for today? The big picture
According to the International Energy Agency's Global Hydrogen Review 2026, global hydrogen demand grew almost 3% in 2025 to surpass 100 million tonnes (Mt), and hydrogen use in industry and refining accounted for almost all of that demand. The same review says demand for low-emissions hydrogen grew by 20% in 2025 to close to 1 Mt. Set against more than 100 Mt in total, that is roughly 1% (our arithmetic, not an IEA figure). In other words, nearly all hydrogen in use today is still made from fossil fuels.
The United States follows the same pattern. The U.S. Department of Energy (DOE) says about 10 million metric tons of hydrogen are produced in the country each year, and that the main demand is for petroleum refining and ammonia production. A 2018 DOE fact sheet put the split at nearly 70% for refining and 20% for fertilizer. That figure is a few years old, but it shows how concentrated the market is.
Oil refining: cleaning up fuels
Refineries use hydrogen mainly to take sulfur out of diesel and gasoline (hydrotreating) and to break heavy oil into lighter, more valuable products (hydrocracking). DOE notes that most hydrogen produced in the United States comes from steam methane reforming of natural gas. The IEA notes that the refining and chemicals sectors are leading the switch to low-emissions hydrogen, largely because policies that create demand are taking hold there first.
Ammonia and fertilizer: hydrogen you eat indirectly
Ammonia (NH3) is made by combining hydrogen with nitrogen from the air. Most of it becomes fertilizer, so a large share of the world's food supply depends on hydrogen. Because the hydrogen is built into the product itself, there is no way to make ammonia without it. The only choice is where the hydrogen comes from.
Methanol and chemicals
Methanol is a building block for plastics, resins and solvents. It is made from hydrogen and carbon (from natural gas or coal today, and potentially from captured CO2 in future). As with ammonia, hydrogen is part of the molecule.
Steel: replacing coal with hydrogen
Most of the world's steel is still made in blast furnaces that use coal-derived coke to strip oxygen from iron ore. In direct reduced iron (DRI) plants, a gas does that job instead. Today the gas is usually from natural gas, but pure hydrogen can do it too, leaving water vapor instead of CO2. DOE lists steel manufacturing among hydrogen's emerging markets. For iron made from ore, hydrogen is one of the few routes that can remove most of the process emissions, which is why it gets so much attention.
How much hydrogen do these products need?
The table below uses basic chemistry (the weight of each atom) to show the minimum amount of hydrogen that ends up in, or is needed to make, one tonne of product. These are illustrative theoretical minimums; real plants use more because of losses and process conditions.
Product | Simplified reaction | Minimum hydrogen per tonne of product |
Ammonia | N2 + 3H2 → 2NH3 | About 178 kg (hydrogen is ~17.8% of ammonia by weight) |
Methanol (from CO2) | CO2 + 3H2 → CH3OH + H2O | About 189 kg |
Iron (from iron ore, Fe2O3) | Fe2O3 + 3H2 → 2Fe + 3H2O | About 54 kg per tonne of iron |
Calculated from standard atomic weights. Illustrative only.
E-fuels: hydrogen as a building block for liquid fuels
E-fuels (also called synthetic fuels or electrofuels) combine hydrogen made with electricity and captured carbon to produce liquids such as e-kerosene for aircraft or e-methanol for ships. Their big advantage is that they work in existing engines, tanks and pipelines. Their big drawback is energy: every conversion step loses some. The IEA says hydrogen-based fuels "are not ready at scale" to ease today's pressures, and that in aviation Europe's mandates remain the only policy driver for adoption. Expect e-fuels to focus on long-haul flights and deep-sea shipping, where batteries can't do the job.
Power generation and backup power
Hydrogen can make electricity in two ways: burned in a gas turbine or engine, or converted in a fuel cell. Its strongest role in power is as long-duration storage, holding surplus renewable energy for weeks or seasons, for example in underground salt caverns, and as clean backup power where diesel generators are used today. The IEA says progress in the power sector "remains slow and concentrated in Japan and Korea."
The catch is round-trip efficiency. Here is a simple illustrative chain using assumed round numbers:
Electricity to hydrogen in an electrolyzer: assume 70% efficient
Compression and storage: assume 90% efficient
Hydrogen back to electricity in a fuel cell: assume 50% efficient
0.70 × 0.90 × 0.50 ≈ 0.32, so only about 32% of the original electricity comes back. These are assumptions for illustration, not measured values for any product. A battery returns far more for daily cycling, which is why hydrogen power makes sense mainly when energy must be stored for a long time or in very large amounts.
Transport: where it is actually used
The IEA reports the global stock of fuel cell electric vehicles grew 20% in 2025 to almost 130,000, driven by truck sales in China and a rebound of car sales in Korea. That is tiny next to battery electric vehicles. Trucks and buses on fixed, heavy-use routes are where hydrogen has the clearest case on the road.
Where hydrogen does and doesn't make sense
Energy analyst Michael Liebreich's widely cited "Hydrogen Ladder" (version 5.0, October 2023) ranks uses by how likely hydrogen is to win them by around 2035. It is one analyst's view rather than official policy, but its logic is useful:
Strong case: uses with no real alternative. Existing uses such as fertilizer and refining sit at the top, since hydrogen is chemically required. Chemical feedstocks and jet aviation fuels sit on the next row down.
Weak case: uses where direct electricity is simpler and cheaper. The ladder places hydrogen cars and bulk e-fuels on its bottom row, and its author concludes there is "essentially no role for hydrogen" in heating, since heat pumps and electric heating are more efficient.
The rule of thumb: use clean hydrogen first where it replaces dirty hydrogen that is already in use, or where molecules are unavoidable. Swapping the roughly 100 Mt of fossil-based hydrogen already in use for low-emissions hydrogen would be a huge job on its own.
What decides whether a hydrogen use is affordable?
For most of these uses, the deciding factor is the cost of producing hydrogen, especially the electricity price and how many hours an electrolyzer runs. The IEA expects low-emissions hydrogen to stay more costly than fossil-based hydrogen in most parts of the world in the near term, apart from China. If you want to understand how that cost is built up, H2Hub explains what the levelized cost of hydrogen (LCOH) is, with a worked example.
Screening a real hydrogen project?
If you're weighing a hydrogen project for ammonia, steel, fuels or backup power, H2Hub lets you start a project screen without an account or card, and the first full project report is free per account. Start a free project screen in H2Hub.
Related reading
Sources
International Energy Agency, Global Hydrogen Review 2026: Executive summary (accessed November 12, 2026)
International Energy Agency, Global Hydrogen Review 2026: Demand (accessed November 12, 2026)
U.S. Department of Energy, Hydrogen Production (accessed November 12, 2026)
U.S. Department of Energy, Fact of the Month May 2018: 10 Million Metric Tons of Hydrogen Produced Annually in the United States
U.S. Department of Energy, H2@Scale (accessed November 12, 2026)
Michael Liebreich, Hydrogen Ladder Version 5.0 (October 20, 2023)
Reaction masses calculated by ReneEnergy from standard atomic weights; efficiency chain uses stated illustrative assumptions.
Fact-checked November 12, 2026.
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