§01 · Methodology
A scientific instrument, not a calculator.
H₂VALIS converts a transparent user scenario into harmonised inputs, calibrated engine results, a delivered-hydrogen cost, financial indicators, environmental and social profiles, uncertainty, evidence confidence and a traceable technical report.
Five governing principles
- 01
Calculate only where evidence supports it
Otherwise show a transparent guide, benchmark, proxy, missing-data state or out-of-scope warning. Every result cell renders value, unit, evidence status, provenance and confidence range.
- 02
Harmonise before comparing
Every literature-derived cost is normalised to a EUR 2024 base then converted to the project's currency and reference year using annual-average FX and inflation, with provenance attached.
- 03
Version every equation
The equation registry stamps every result with the exact equation version used. Reproducibility packages travel with every downloaded report.
- 04
Uncertainty is not R²
R² describes fit quality of a curve — it is not prediction uncertainty. Uncertainty is expressed via low/base/high scenarios, parameter distributions and Monte Carlo propagation.
- 05
Never auto-reject a project
The preliminary production-only gate offers 'continue / revise / save-and-stop'. Language is favourable / marginal / unfavourable / insufficient information — never 'better than the bank'.
§02 · Evidence status system
Every number wears one of five tags
Derived from a first-principles or peer-reviewed equation inside the H₂VALIS engine, using inputs that fall inside the equation's validity range.
Reported directly by a cited technical study, harmonised to the project year/currency; propagation carries the source's own uncertainty band.
Estimated by analogy to a comparable geography, sector or technology. Flagged prominently; excluded from decision-critical claims.
A user-defined or benchmark scenario input (e.g. hydrogen sale price, uncertainty draw). Not a measurement.
The indicator is applicable but calibrated evidence has not yet been incorporated. Shown as a badge; no numeric value is displayed.