A supplier offers you “clean” hydrogen, and you need to know what is green hydrogen before signing. It is hydrogen made by electrolysis, splitting water with electricity from renewables such as solar or wind. The label holds only when the electricity is renewable.
Most of the confusion comes from colour labels, cost claims and emissions shortcuts. This guide works through them, and it sits within our wider coverage of environmental technology for business.
Green hydrogen in plain terms
Green hydrogen is hydrogen gas produced by electrolysis, with renewable power driving the process. The US Department of Energy’s Alternative Fuels Data Center explains that hydrogen is bound up in other compounds and must be separated using chemical or electrochemical reactions. In electrolysis, an electric current splits water into hydrogen and oxygen. If solar or wind produces that electricity, the resulting hydrogen is renewable. If the electricity comes from a fossil-heavy grid, the process is the same but the hydrogen is not green.
The colour names are shorthand for the production route. The table below sets the three you will meet most often side by side.
| Type | How it is made | Cost and share | Planning use |
|---|---|---|---|
| Green | Electrolysis of water with renewable electricity | $3-8/kg depending on location, down from over $10/kg a decade ago | Best fit where a low-carbon claim matters and cheap solar or wind is available |
| Grey | Natural gas without carbon capture | $1-2/kg; about 95% of current production | The price benchmark that green hydrogen is measured against |
| Blue | Natural gas with carbon capture and storage | Potentially lower-cost near-term pathway; emissions depend on methane leakage | A transition option only if capture performance and gas supply emissions can be verified |
Figures are from Council Fire’s green hydrogen glossary, with the electrolysis process described by the Alternative Fuels Data Center.
Common misunderstandings about hydrogen colours and cost
“Hydrogen is already a clean fuel”
Most hydrogen in use today is not clean. Natural gas reforming with steam accounts for the majority of hydrogen produced in the United States each year. Council Fire’s glossary describes grey hydrogen as natural gas without carbon capture and puts it at about 95% of current production, with global demand supplied almost entirely by grey hydrogen. A buyer who simply asks for “hydrogen” is therefore most likely to receive the grey kind. Ask for the production route in writing.
“Green hydrogen already costs the same as grey”
It does not. Council Fire reports that green hydrogen has fallen from over $10/kg a decade ago to $3-8/kg depending on location. Its FAQ gives a current range of $4-8/kg, roughly 2-4 times grey hydrogen at $1-2/kg. The most competitive projects, in regions with excellent solar or wind resources, are approaching $3/kg.
Two decisions follow from this:
- Treat location as a cost lever. Electricity represents 60-70% of production expense, so a site with strong solar or wind resources shapes the price far more than the choice of equipment brand.
- Do not budget at the best-case figure. The lowest published cost reflects favourable regions. A project elsewhere should be modelled nearer the upper end of the range until its own power price is known.
“Blue hydrogen is just green by another route”
Blue hydrogen starts from natural gas and relies on capture to cut emissions. Council Fire notes that it offers a potentially lower-cost near-term pathway, but that at methane leakage rates above 3%, common in many gas systems, its emissions may exceed those of unabated natural gas. Capture only helps if the upstream gas supply is tightly controlled. The guide to Carbon Capture And Storage Projects: How They Work, Where They’re Succeeding, And What’s Next In 2026 – Greencrowding explains how those projects work and where they perform well.
“Green means zero emissions everywhere”
A vendor explainer from SICK says hydrogen produced with green energy has a neutral carbon footprint because combustion yields primarily water vapour. That describes the point of use only. Whether the hydrogen counts as renewable depends on the electricity feeding the electrolyzer, as the Alternative Fuels Data Center makes clear. Check the power source before accepting any low-carbon claim.
Electrolyzers and the electricity behind them
An electrolyzer is the device that performs the water splitting, and its type affects both cost and operation. Council Fire lists three competing technologies: alkaline, proton exchange membrane (PEM) and solid oxide. PEM units respond faster and are more compact, but carry a higher capital cost. That makes them a better match for projects with variable renewable input and limited space, while a steady supply and a tight capital budget favour comparing alternatives more closely.
Capital cost is moving in the right direction. Council Fire cites electrolyzer costs falling from roughly $1,500/kW in 2020 toward a projected $300-500/kW at scale by 2030. Treat the projection as a planning scenario rather than a quote, since it depends on manufacturing scale.
Because electricity is the largest share of production expense, the power arrangement matters as much as the electrolyzer. A project that secures cheap, renewable supply, whether co-located or contracted, starts with the biggest cost advantage available.
Where green hydrogen can be deployed
The strongest cases are where hydrogen is already needed or where batteries struggle. Fuel cells, which convert hydrogen back into electricity, make hydrogen an energy carrier for energy storage, building electricity and vehicle power.
- Existing industrial demand. The Alternative Fuels Data Center reports that almost all hydrogen produced in the United States goes to refining petroleum, treating metals, fertilizer and food processing. These users already buy hydrogen, so switching the supply from grey to green changes the source rather than creating a new market.
- Steel. Council Fire cites SSAB’s HYBRIT project in Sweden, which has produced the world’s first fossil-free steel using hydrogen reduction. It is a proof point for steelmakers weighing a switch.
- Heavy transport. Council Fire notes that hydrogen fuel cells power heavy-duty trucks, buses, trains, and potentially ships and aircraft. Fleets with fixed routes and central refuelling suit this best.
- Storage and buildings. Fuel cells let hydrogen serve as stored energy for building electricity, as described by Engie’s explainer.
Delivery is a practical constraint. The Department of Energy resource notes that the pipeline network for hydrogen delivery in the United States is limited, so projects that produce close to where the hydrogen is used depend less on that network. Hydrogen is also one tool among several for heavy industry. For a different route in cement, see Cement Carbon Capture: Practical Paths To Net‑Zero Cement In 2026 – Greencrowding.
Policy signals worth checking
Public targets and incentives shape project economics, and the Alternative Fuels Data Center summarises the main US signals.
- Production tax credit. A clean hydrogen credit provides up to $3/kg to eligible producers over 10 years, scaled by carbon intensity. Cleaner production earns more, so project design and power source feed directly into the credit.
- Clean hydrogen standard. A standard of 4 kg CO2e/kg H2 (well-to-gate) has been introduced, giving buyers a measurable benchmark for emissions claims.
- Cost target. The Hydrogen Shot seeks to reduce the cost of hydrogen by 80% to $1 per 1 kg in 1 decade. It is a goal, not a current price, and should not be used for budgeting.
Before committing to a supply deal, confirm which of these apply to the project and what carbon-intensity evidence the supplier can provide.
Frequently asked questions
| Question | Answer |
|---|---|
| Is green hydrogen emission-free? | Not automatically. A vendor explainer from SICK says combustion produces primarily water vapour, but the hydrogen is only renewable if the electricity used in electrolysis is renewable, according to the Alternative Fuels Data Center. |
| How is hydrogen stored and moved? | Council Fire says hydrogen can be stored as compressed gas or liquefied at -253°C. For delivery, the Department of Energy resource notes about 1,600 miles of hydrogen pipelines in the United States. |
| How much hydrogen does the world use? | Council Fire describes global demand as almost entirely supplied by grey hydrogen. An explainer from Engie gave worldwide consumption as 74 million tonnes, under 2% of global energy consumption. Together these points show how small green hydrogen’s share still is. |
| What makes green hydrogen more expensive than grey? | Electricity represents 60-70% of production expense, and electrolyzers still carry high capital costs, according to Council Fire. Cheap solar or wind narrows the gap. |