Relationship, requires input

Power transformer requires input Refined copper

The stored status is what a reviewer approved. The level below it is what the overlapping data support; the two are shown side by side and only a human moves the status.

Stored statusEstablished relationEvidence level (latest analysis)not analysed yet

Mechanism, evidence, reviewer judgements

The edge as stored

Power transformer requires input Refined copper3 evidenceEstablished relation

Power transformer depends on Refined copper.

Mechanism

Transformer windings are conductors carrying the full load current. Copper is the standard winding material for its conductivity and mechanical strength; aluminum windings are used in many distribution transformers at a larger cross-section.

Evidence

documentUSGS, Copper statistics and informationusgs.govEnd uses (building construction, electrical and electronic products) and substitutes (aluminum in power cables and some transformer windings).checked 2026-09-07
documentIEA, The Role of Critical Minerals in Clean Energy Transitionsiea.orgCopper and aluminum intensity of grids and electrical equipment.checked 2026-09-07
sourceUSGS National Minerals Information CenterSeeded source; commodity summaries are the cited documents.checked 2026-09-07

Substitutes for Refined copper

aluminum Aluminum windings, larger cross-section for the same current; common in distribution transformers.

Status: established_identity_or_engineering_relation
Reviewer confidence: 0.95
Stated strength: 0.80
Lag: not stated
Version: curated_seed_v1
Reviewed: 2026-09-07

Confidence and strength are curated judgements recorded with the edge, not measured quantities.

Entity pages: Power transformer, Refined copper. Part of the mechanism More delivered electricity needs more transformers, which need copper, aluminum and electrical steel.

Not computed

Statistical evidence

No analysis has been stored for this edge. The causal.analyze_all job runs monthly over every edge with a catalog metric linked to both entities; edges without a series on both ends are not analysed.

Not computed

Causal estimate

A causal estimate needs at least 20 overlapping periods and was not attempted for this edge yet.

What each rung means

Levels

Level 0: No association found
the overlapping data show no significant association.
Level 1: Correlation only
statistically associated in the overlapping periods; no direction, no mechanism.
Level 2: Predictive lead/lag
one series historically contains predictive information about the other.
Level 3: Mechanism supported
a documented physical, economic or institutional mechanism with cited evidence.
Level 4: Causally supported
a backdoor-adjusted estimate that survived refutation, on stated assumptions.
Level 5: Established relation
follows from engineering, accounting or scientific structure.

Every stored run, newest first

Analysis history

No runs stored.