Method · illustration
A grade, step by step
How a data center's facts become a letter, from A to E. A grade is built in two stages: indicators make each pillar, pillars make the grade. Expand a pillar to audit its score.
This is an illustration. It shows the intuition of the calculation — the path from data to a letter — not its depths. The exact thresholds, the confidence level and the “announced ≤ proven” cap live in the full method. The goal: understand, not reproduce. The numbers are deliberately simple.
The example site
A fictional data center — the raw material of the calculation.
Stage 1 — indicators make each pillar
Each pillar aggregates its indicators. We expand just one — Energy, the heaviest — to watch its score being built. The principle is the same for all five: expand them if you like.
Energy weight 25 % sub-score 48 · D
Water weight 20 % sub-score 47 · D
Land & biodiversity weight 20 % sub-score 58 · C
Local impact weight 20 % sub-score 60 · C
Transparency & governance weight 15 % sub-score 50 · C
Stage 2 — pillars make the site grade
The five sub-scores, each at its weight, combine into a global score — and a letter.
And what would have made it a B?
The letter does not reward an average: it counts the pillars under tension, and how severe they are.
- A no marked weakness on the pillars published
- B solid, with one shadow
- C two clear tensions — our example's case
- D several pillars in the red
- E one major tension, or red almost everywhere
A single very poor criterion is enough to pull the letter down — that is deliberate, as with the food Nutri-Score. And the cap only lifts on third-party verified proof: no site in Europe reaches A today.
Why we don't publish the numeric thresholds →What we don't show here
That's the intuition. The real calculation goes further.
A weak pillar weighs but doesn't destroy. It isn't everything. Under the hood, the method adds:
- Two grades: site (endured) & project (chosen)
- Minimum indicator coverage
- A confidence level per grade
- The “announced ≤ proven” cap
Pedagogical illustration · deliberately simple numbers on a zz-demo fixture. The real thresholds are in the method.