Glossary

Concepts

These are the concepts we lean on throughout TEA. Each page covers one topic in the context of building a techno-economic analysis — what it is, how it's used, and where it tends to break — and stands on its own, so you can read just the one you need. They're grouped by layer below; 14 so far, with more on the way.

Structural 2

• Capacity factor The capacity factor (CF) is the ratio of a plant's actual output over a period to what…
• System boundary A system boundary is the line an analysis draws around a process, separating what it…

More structural concepts are on the way — one we should cover? hello@tea-commons.org

Mass & Energy 1

• Mass balance A mass balance is the accounting statement that, at steady state, the mass entering any…

More mass & energy concepts are on the way — one we should cover? hello@tea-commons.org

Economic 7

• Accounting (capex, opex & revenue) Accounting is the money ledger of a TEA: the one-time cost to build the plant (capex),…
• Capex estimation (equipment-first build-up) Estimating capex means building the plant's one-time capital up from the ground: cost…
• Capital recovery factor (CRF) The capital recovery factor (CRF) is the multiplier that converts a one-time capital sum…
• Cost of capital The cost of capital is the minimum annual return a project must earn to justify the…
• Discounted cash flow (DCF) Discounted cash flow (DCF) values a project by projecting its net cash flow in every…
• Levelized cost (e.g., $/t NH₃) Levelized cost is the constant per-unit cost — dollars per tonne of product — that,…
• Six-tenths rule The six-tenths rule estimates the cost of equipment at a new size by scaling a known…

More economic concepts are on the way — one we should cover? hello@tea-commons.org

Analytical 2

• False precision False precision is presenting a number with more apparent exactness — more significant…
• Tornado chart A tornado chart is the standard display of a one-way sensitivity analysis — varying one…

More analytical concepts are on the way — one we should cover? hello@tea-commons.org

Cross-cutting 2

• TEA Readiness Levels (TEA-RL) The TEA Readiness Levels (TEA-RL) are a four-level ladder describing how far a…
• Uncertainty & accuracy class (FEL-1/2, ±30%) An accuracy class is the ± band a TEA result carries, fixed by how mature and resolved…

More cross-cutting concepts are on the way — one we should cover? hello@tea-commons.org