Green hydrogen

The short version

Green hydrogen is hydrogen produced by splitting water molecules (H₂O) into hydrogen and oxygen using electricity from renewable sources — a process called electrolysis. Unlike grey hydrogen (made from natural gas via steam methane reforming, producing significant CO₂) or blue hydrogen (grey hydrogen with carbon capture), green hydrogen produces no direct carbon emissions.

The physics is straightforward. The economics are harder. Green hydrogen currently costs $4–8/kg to produce, compared to $1–2/kg for grey hydrogen. Closing that gap through electrolyzer cost reductions, cheap renewable electricity, and the IRA's 45V hydrogen production tax credit is the central challenge of the nascent green hydrogen industry.

How electrolysis works

An electrolyzer passes an electric current through water, causing it to split into hydrogen gas at the cathode and oxygen at the anode. The two dominant electrolyzer technologies are PEM (proton exchange membrane) and alkaline. PEM electrolyzers respond quickly to variable renewable electricity, making them well-suited for co-location with wind and solar. Alkaline electrolyzers are more mature and typically lower cost, but less flexible. Solid oxide electrolyzers (SOEC) are an emerging high-efficiency technology still in early commercial deployment.

The cost challenge

Green hydrogen's cost is dominated by the electricity input — roughly 55–65 kWh of electricity is needed to produce 1 kg of hydrogen. At $30/MWh electricity, that's $1.65–$1.95/kg in electricity cost alone, before electrolyzer capital costs, compression, storage, and transport. For green hydrogen to compete with grey hydrogen at $1.50/kg, electricity costs need to fall to $15–$20/MWh and electrolyzer capital costs need to drop 60–70% from current levels.

The 45V hydrogen production tax credit

The IRA's Section 45V creates a production tax credit for clean hydrogen based on lifecycle carbon intensity — up to $3/kg for hydrogen with less than 0.45 kg CO₂e/kg H₂. The One Big Beautiful Bill Act, signed July 4, 2025, extended the 45V begin-construction deadline from December 31, 2025 to January 1, 2028 — making 45V the rare clean energy credit that became more generous under OBBBA rather than less. This is potentially transformative economics for green hydrogen projects, though the Treasury's guidance on how additionality, temporal matching, and deliverability requirements apply has been contentious. Green hydrogen projects with access to very cheap renewable electricity and qualifying under the 45V rules may achieve effective costs competitive with grey hydrogen at scale.