Delivered vs Produced Hydrogen

In plain terms

Between the electrolyzer stack and the customer's flange, hydrogen is lost at several points:

• Gas conditioning: hydrogen burned in the deoxo and purge gas from the dryer.
• Compression: small leaks and recycle.
• Storage: venting and leaks. Cushion gas is different: it is a one-time fill, counted as an initial cost, not a recurring loss.
• Operations: start-up and shutdown purges, and gas vented on safety trips.

Produced hydrogen is measured at the stack. Delivered hydrogen is measured at the custody-transfer point. The difference is the plant's internal loss.

Typical range

There is no single figure: the gap depends on purity grade, dryer design, compression and storage configuration, and how often the plant cycles. As one measured example, a vacuum-assisted PSA dryer on a 50 kW alkaline electrolyzer recovered 98.4 % of the hydrogen, a 1.6 % loss at the drying step alone (Ligen et al., 2020).

Why it moves LCOH

LCOH is total discounted cost divided by discounted hydrogen output. The NREL H2A method, used by the US DOE, solves for the minimum hydrogen price that meets a target rate of return, which only makes sense on hydrogen that is actually sold. Using stack output instead inflates the denominator and understates cost per kilogram by the full loss share. It also hides the cost of the equipment that causes those losses.

Common mistake