Concept
The TEA Readiness Levels (TEA-RL) are a four-level ladder describing how far a techno-economic model has been built out — from a one-line process sketch to a diligence-grade model — with each level fixed by the depth of its scope, the quality of its data, and the analysis it can support. It grades the analysis itself, distinct from the technology behind it (not a Technology Readiness Level) and from the error bar on the answer (its accuracy class). It is a handbook-specific framework, not an industry standard like the FEL/AACE estimate classes.
What it is. A TEA is built up layer by layer, in increasing depth, precision, and accuracy; TEA-RL names four resolved stops along that path. Each level is set by three things: the objective it serves, the key question it can answer, and the concrete contents of the model at that stage — its process flow, cost build, cost data, sensitivities, visuals, and scenario handling. The same model is a different level at different stages of build-out, even for an identical technology.
| Level | Objective | Key question it answers | Owner |
|---|---|---|---|
| 1 | Outline the basic process concept | What unit operations does this require? | Founders |
| 2 | Establish a first-pass, end-to-end economic picture | Is there an economically viable concept here? | Founders |
| 3 | Build a robust model for internal decisions and optimization | Which unit operations and assumptions need more granularity? | Founders + engineer |
| 4 | Create a high-fidelity model suitable for external diligence | Which technical or strategic levers most improve feasibility? | Founders + engineer |
What deepens between levels. The ladder isn’t about polish — it’s about resolution. Each row below sharpens as the level climbs:
| Dimension | Level 1 | Level 2 | Level 3 | Level 4 |
|---|---|---|---|---|
| Model footprint | Block-flow sketch | ~2 connected sheets | ~4–7 sheets, 2–3 deep-dives | ~8–12 sheets, heavy validation |
| Process flow | Block-flow diagram | All unit ops in one sheet, ~4–5 lines each | ~8–10 lines each; core-tech deep-dives | Adds auxiliaries (utilities, wastewater) |
| Data input | Desktop refs for a few key assumptions | Rough estimates / comps for all assumptions | Detailed ranges, expert-validated, some quotes | Multiple vendor quotes; dedicated validation tabs |
| CAPEX | Order-of-magnitude equipment list | ~2–3 priced items per unit op → total capex; annualized via CRF | Sizing tied to flow; 2–3 refs per major driver; plant- and unit-level comps | 5+ refs for the ~10 biggest drivers; vendor quotes for core tech |
| Variable costs & pricing | Datapoints for 2–3 main inputs/outputs | All costs linked to the mass & energy balance; incl. consumables | Referenced ranges for all main inputs/outputs | Validated, location-specific pricing; offtake pricing |
| Fixed costs | — | Rough % of capex or revenue | Bottom-up labor, maintenance, overhead | Detailed staffing plan; taxes, insurance |
| Sensitivities | — | Rough (waterfall + tornado) | Univariate sweep across a comprehensive variable set | Univariate + multivariate; scenarios |
| Visuals | Market-sizing waterfall | Unit-economics waterfall; tornado chart | Comps, cost curves | Advanced analysis visualizations |
| Scenarios | Single base case | Base case | Dashboard over a defined set (e.g. high/low price); feedstock/output toggles | Integrated scenario manager; version control + changelog |
Relationship to accuracy class. TEA-RL and accuracy class read the same maturity axis from opposite ends. TEA-RL describes the model you built — how resolved its scope, data, and analysis are; accuracy class describes the ± band on the answer that resolution earns. They move together: a Level-1 outline supports only an order-of-magnitude (FEL-1 / AACE Class 5) result, while a Level-4 diligence model built on vendor quotes can carry a far tighter class. The level is the input maturity; the class is the output tolerance.
Distinct from a Technology Readiness Level. A TEA-RL grades the economic analysis; a Technology Readiness Level grades the technology. The two are independent: a bench-scale process (low technology readiness) can carry a thoroughly built Level-3 model, and a commercially mature technology can sit behind a Level-1 back-of-envelope. The shared “readiness level” name is the only thing the two scales have in common.