Pre-FEED and FEED
A pre-FEED study and FEED are the front-end engineering stages that take a hydrogen project from a chosen concept to a design and cost estimate firm enough for investment.
In plain terms
Large hydrogen projects move through gated stages. Each stage spends more money to remove more uncertainty before the next decision.
- Concept or screening: is the site worth studying? Rough sizing and cost.
- Pre-FEED: compare configurations, such as electrolyzer technology, solar-wind mix, storage and water source, and select one.
- FEED (front-end engineering design): develop the selected option into process flow and P&ID drawings, equipment data sheets, a plot plan and a cost estimate firm enough to tender the EPC contract.
- Final investment decision (FID), then detailed engineering, procurement and construction.
Typical range
AACE RP 18R-97 classes estimates by project definition, not by study name. In common practice, a pre-FEED estimate sits around Class 4 (1 to 15 % definition) and a FEED estimate around Class 3 (10 to 40 %). Study cost and duration scale with plant size, scope and the number of options screened, so there is no single benchmark. The better measure of a study is the estimate class it delivers.
Why it moves LCOH
The configuration chosen in pre-FEED locks in much of the plant's lifetime cost. Electrolyzer pressure, oversizing ratio and storage strategy are hard to change once FEED starts. A well-screened pre-FEED therefore protects LCOH more than most later optimisation.