Public evidence

electrical.kwh_to_watts

Machine-checked verification for calculation version 1.2.1 · tier engine_tested

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Verification

12/12 calculation tests · Production surface contract 4/4

Golden tests 12 / 12
Boundary tests 0 / 0
Property tests 0 / 0
Production surface contract 4 / 4
Engine tested Yes
Source checked Yes
Artifact integrity PASS
Production attestation Embedded snapshot: STALE · Last attested schema matched 1.2.1 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
Semantic contract PASS
Evidence attested at 2026-09-16T06:44:24.203Z
Last production check 2026-09-16T06:44:24.203Z
Public / cache PASS
Origin PASS
Supplemental domain review Not performed
Named expert review Not performed

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS

Fingerprint sha256:2f1243deb47ae5d58324b74d1c5a729429371ccd16a27ccbd6e28b9b5b375e05

Input schema sha256:36e03de4cc6a5f64bdde21771eed9c9ef1588b32cd0bf841ea44730e408d23cb · Output schema sha256:ebe8b63eb3d9e96be3160fd6e10cb21f9aca1d8ca48e6fefe6f1a2c5f3f91e75 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: kwh-to-watts
Engine: scale-quotient
Engine build: 2026-09-15
Evidence core: 2026-09-15T06:31:46.555Z
Rendered: 2026-09-16T22:03:43.707Z
Last reviewed: —

Assumptions

Power is the average over the stated period
Time is expressed in hours

Limitations

Average power over the interval — not instantaneous peak
Time must be in hours
Shares the scale-quotient helper with W→kVA; contracts are distinct (time vs PF)

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

Energy–power identity — E = P × t; W = 1000 × kWh / h
Supports: P(W) = 1000·E(kWh)/t; E = P·t/1000
NIST Guide to the SI (SP 811) — Watt, joule, and watt-hour relationships
Supports: 1 kWh = 3.6 MJ; 1 kW = 1000 W scaling
IEC 60050 — International Electrotechnical Vocabulary — Active power (IEV 131-11-42)
Supports: P is active power; unit watt (W)
IEC 60050 — International Electrotechnical Vocabulary — Watt hour (IEV 131-11-58)
Supports: 1 Wh ≔ 3600 J; kWh is the common multiple for billing / energy meters
BIPM SI Brochure (9th edition, version 4.01) — Watt, joule, and hour · 2026-06 · DOI
Supports: P = E/t; 1 kW = 1000 W; 1 kWh = 3.6 MJ

Published checks

Golden, boundary, and property cases included in this evidence build.

ID	Kind	Status	Detail
`1kWh-1h`	golden	pass	Expected 1000 · Actual 1000
`3-6.5`	golden	pass	Expected 461.538 · Actual 461.53846153846155
`12-24`	golden	pass	Expected 500 · Actual 500
`w-to-kwh`	golden	pass	Expected 7.5 · Actual 7.5
`10-5`	golden	pass	Expected 2000 · Actual 2000
`1000W-1h-reverse`	golden	pass	Expected 1 · Actual 1
`linear-2x-E`	golden	pass	Expected 923.077 · Actual 923.0769230769231
`inverse-half-t`	golden	pass	Expected 923.077 · Actual 923.0769230769231
`soft-zero-t`	golden	pass	Expected 0 · Actual 0
`soft-zero-E`	golden	pass	Expected 0 · Actual 0
`soft-zero-P-reverse`	golden	pass	Expected 0 · Actual 0
`soft-zero-t-reverse`	golden	pass	Expected 0 · Actual 0