Scott Wise · August 29, 2026
Every announcement states an entry and an exit TRL. It is not scored. It is the gate you pass before scoring starts, and a technology ranked too low or too high against the stated band is rejected. Below are DOE's definitions for levels 1 through 7, with what actually establishes each rung. Levels 8 and 9 exist; federal R&D rarely funds there.
| TRL | DOE definition | What frames the level |
|---|---|---|
| 1 | Basic principles observed and reported | Published research identifying the underlying principle. Paper studies and observation of the physical world. No application yet. |
| 2 | Technology concept and/or application formulated | A practical use has been named. Analytic work only. DOE's own wording: applications are speculative, and there may be no proof or detailed analysis to support the assumptions. |
| 3 | Analytical and experimental critical function and/or characteristic proof of concept | Lab work has verified the concept on separate elements. Components validated individually, with no attempt to integrate them into a system. |
| 4 | Component and/or system validation in a laboratory environment | The pieces work together. Low fidelity compared with the eventual system — ad hoc hardware, bench conditions, small-scale tests. |
| 5 | Laboratory scale, similar system validation in a relevant environment | Same components, but the system configuration now matches the final application in almost all respects and is tested against realistic conditions. This is the entry gate on most federal R&D announcements. |
| 6 | Engineering or pilot-scale, similar prototypical system validation in a relevant environment | Step up from laboratory to engineering scale. Scaling factors determined. The prototype performs every function the operational system will require. |
| 7 | Full-scale, similar prototypical system demonstrated in a relevant environment | Full-scale prototype in the field. Final design virtually complete, with results analysed against the eventual operating environment. This is the exit gate on most federal R&D announcements. |
The definitions provided above are published in the DOE funding announcements. Other agencies use scales that differ in wording and scope. Never assume government continuity: refer to the definitions relevant to your agency application.
Both are laboratory work. The difference is the environment you tested in. TRL 4 is bench conditions. TRL 5 is conditions that represent where the technology will actually operate.
The solicitation defines the relevant environment, not you. If an announcement specifies sub-1-millidarcy rock at reservoir temperature, then lab work at conventional conditions is TRL 4 evidence no matter how rigorous it was.
This is why one technology can hold two different numbers at the same time. A product with ten years of commercial results in one environment can be scored TRL 3 for a new use case, because none of the testing was done under the conditions the announcement names. The technology did not change. The intended use did.
Write down the operating environment the announcement names: permeability, temperature, pressure, salinity, duty cycle, whatever it specifies. Conventional and unconventional wells are not the same environment, and performance at altitude is not the same as performance in a pressure test chamber. Then list what you have tested, and under which of those conditions. Where the two lists diverge is your real TRL. The gap to the entry gate is your work plan.
The band is published in the announcement. Your evidence is in your own files. The comparison takes an afternoon. If the two do not line up, that is worth knowing in week one rather than week eleven.
Use the NOFO specification as the only guide. TRL definitions vary between agencies and occasionally even between departments or programs within the same agency.
Other helpful resources: the federal acronym glossary, the engagement checklist, and current open opportunities.