WAI Extension: Energy Methods

Mirrored from the canonical text at commit c5e7133e (2026-11-11).

Status: Draft. Registers no capability. Maps WAI’s signed energy records onto the methods the media and ICT industry uses to measure and report energy and emissions, method by method: what quantity each asks for, over what functional unit and boundary, which fields of which WAI record supply it and under what conditions, where a WAI record supplies more (a signed reading that names its counter, its span and its acquisition class), and where it supplies nothing. A field WAI cannot supply is stated as not supplied, with the reason; nothing is estimated to fill it. It defines two figures of WAI’s own, energy per viewing hour and per gigabyte delivered, with their exact numerators and denominators (§5); a signed, location-based factor table an operator supplies, the only way carbon enters (§6); and an export, a signed document that states each method’s report form from a set of signed records and a factor table, every figure naming the records it rests on, a partial total marked partial and no two classes ever summed (§7, §8), with its verification (§9). The reference implementation is the energy_methods module of wai-rs (feature energy_methods); the corpus is live-conformance/energy-methods/, written by wai_energy_methods_vectors, and its second implementation is live-conformance/energy_methods_verify.py. Keywords MUST, MUST NOT, SHOULD, MAY are RFC 2119/8174.

Texts read for this revision, each the revision named (decision D43 names each file read by the first and last eight digits of its SHA-256):

• ITU-T L.1333 (09/2022), edition 1.0, Carbon data intensity for network energy performance monitoring, whole.
• ITU-T L.1480 (07/2025), edition 2.0, Enabling the Net Zero transition – Assessing how the use of information and communication technology solutions impacts greenhouse gas emissions of other sectors: clauses 1 to 14 and Annex A; its appendices in part.
• GHG Protocol Scope 2 Guidance (2015), as published with its electronic corrections to April 2025: chapters 4 to 7. A revision was in public consultation from 2025-10-20 to 2026-01-31 and is not yet a standard; this text maps the 2015 guidance.
• GHG Protocol ICT Sector Guidance (July 2017), built on the Product Life Cycle Standard: chapters 1, 2, 4 and 6, and the Product Standard’s §13.2 for the report.
• ISO/IEC 21031:2024, edition 1.0: its text is sold, and the publisher’s page refused an unattended fetch, so it was not read. The Green Software Foundation’s public SCI specification was read in its versions 1.0.0 (which the Foundation states became the ISO standard) and 1.1.0.
• The Green Software Foundation’s SCI for AI, ratified for public review 2025-12-17: the ratification-era text and the later main and development texts of 2026.
• The DIMPACT methodology, version 1.0 (October 2022), whole, with the public papers that describe its model. Its tool and input tables are given to members only and were not read.
• Greening of Streaming: its nine public publications (May 2023 to February 2026). It has published no reporting format; its members’ area was not read.
• AFNOR SPEC 2314 (June 2024): its text is behind a registration form and was not read; the public summary its government sponsor published was.
• Blauer Engel DE-UZ 215, Ressourcen- und energieeffiziente Softwareprodukte, edition January 2020, version 6 (07/2026), with its annexes, whole.
• UNE 0086:2025 (edition 2025-10-08, corrected 2026-07-29): its text is reached only through a store’s checkout and was not read; its public scope and the sponsor’s release were.
• CEN/CLC/TR 18145:2025: sold, not read; its public scope pages were.

1. Scope

In scope: what WAI’s energy records supply to each method (§3, §8); the rules every statement of a WAI figure under a method follows (§4); WAI’s own derived figures (§5); the factor table (§6); the export, its forms and their CSV (§7, §8); its verification (§9).

Out of scope: how a figure is measured, which energy-measurement governs; a method’s own rules for what an organisation must report; and any statement that a method is satisfied. An export is a record of what signed records state, in the fields a method names. It is not a submission under any method or regime and claims to satisfy none: how an organisation enters a figure in its own inventory, and what it adds from other sources, is its own. An export compares nothing with anything: it states no baseline, no saving and no avoided emission, and a field a method defines for one of those is stated as not supplied (§4, rule 7).

Relationship to other documents:

• energy-measurement. Every figure an export states carries the acquisition class of its §2, and its rules hold: an unmetered figure is not zero (§2), a class says what backs the uncertainty and not where the counter sits (§2.2), a figure is scoped to what its counter reports (§5), and an estimate is presented as one (§9.4, §9.5).
• energy-binding §4. Carbon is a modelled quantity beside the measured joules, never in their place, and is never derived from a grid factor and presented as measured. §6 here is the one way an export states carbon.
• live-metering, sink-energy and task-fidelity §5. The records an export reads (§3.1), each verified by its own extension’s verifier.
• receipt-ledger §5.2. The registry of record kinds. An export names records by the kinds registered there: 1 (WMR1), 2 (WMH1), and the kinds this extension registers there, 28 (a sink session receipt), 29 (a sink segment receipt), 30 (a split-computation claim) and 31 (a factor table, §6).
• receipt-ledger §6.6. An export’s energy rows follow the same rule as an invoice’s: one row per class, max_ppm the largest declared relative uncertainty of tags 4 and 5, whole or partial.

2. Terms

• Figure: one energy figure of one record, in microjoules, with its acquisition class (energy-measurement §2); or the unmetered marker, which is not a figure of zero joules.
• Class: CalibratedInstrument (tag 5), OnChipCounter (4), ModelBased (2) or Estimator (3) (energy-measurement §2.7). HwShunt is never a class of a figure an export states: every record an export reads refuses it (energy-measurement §2.6).
• Component: where in a delivery a figure was spent (§3.1): delivery_relay, delivery_compositor, delivery_ingest, device_decode, device_display, computation_head, computation_tail, in that order.
• Coverage: whole or partial (energy-binding §4).
• Span: the instants a figure was spent over, [from_us, to_us), in microseconds since 1970-01-01T00:00:00Z, ignoring leap seconds.
• Region: a label of 1 to 64 characters from a–z, 0–9 and -, neither first nor last a hyphen, naming a grid area as the operator’s factor table names it.
• Scope of a factor: generation (the emissions of generating the electricity only) or lifecycle (generation with the fuel supply chain and transmission and distribution losses).
• Source: the records an export reads together under one head (§7.1).
• Reference to a record: { "kind": <record kind>, "id": <64 hex digits> }, the kind from receipt-ledger §5.2 and the identity its own extension defines.
• JCS: RFC 8785. Hexadecimal is lowercase. A quantity is a non-negative integer written as a JSON string of decimal digits with no leading zero ("0" for zero); every other number in a record of this extension is a JSON integer from 0 to 2⁵³ − 1. ⌊x⌋ is the floor, and every division is exact integer arithmetic.

3. What the records supply

3.1 The records an export reads

A sink session receipt’s origin and relay entries are not figures of an export. Each restates a hop’s own record (sink-energy §6.4), which reaches an export as that hop’s figure in a room source, once.

Where a WAI record supplies more than a method asks: every figure names the class that backs its uncertainty, and for the hardware classes a declared standard uncertainty with its window (energy-measurement §2.3); a hop’s figure names the hop’s key and the span it covers, and is signed by that key; a sink’s decode figure names its counter profile and the fabrics it covers (energy-measurement §9); a measured figure was sealed only from a live rail and a bracket whose ratio met energy-measurement §4. No method this text maps asks for any of these, and the forms carry the class and the largest declared uncertainty beside every figure so that none is lost.

3.2 Records an export of this revision does not read

These carry figures a method could use; this revision maps them and its export does not read them. A later revision that reads one adds it to §3.1.

• An energy binding (energy-binding): microjoules, acquisition, coverage, workUnits and method for one reconstruction. No Ed25519 key signs it, so an export, which cites what its signer signed, does not read it.
• JWP object and group receipts and energy claims: a figure per object, its class in the object’s leaf or in the claim (energy-measurement §1). They supply a per-object functional unit (an image, a segment, a frame) for the methods that state one.
• OER/2 receipts (oer-receipts §3.1): a job’s energy.joules_total with its class in minor version 1, and the evidential grade of its §2. They supply a data centre’s processing energy per job.
• An invoice’s energy rows (receipt-ledger §6.6): per scope and class, already summed. An export reads the records the rows were summed from instead.
• delivery-telemetry observations carry no energy figure and are signed by nobody (its §1). They supply nothing here.

3.3 What no WAI record supplies

No WAI record states, and an export therefore never states:

• Embodied emissions: raw material, manufacture, transport, installation, end of life.
• The energy of networks between hops: core, metro and access networks, a home gateway. A hop’s figure is its own (live-metering §4.6: an attributed share says nothing of what the network between hops spent), and a sink reads no network’s energy (sink-energy §1).
• Site energy: cooling, power feeding and the building around a hop. A figure is scoped to its counter (energy-measurement §5).
• Contractual instruments: certificates, power purchase agreements, supplier rates. An export states no market-based figure.
• Where a sink is, or when it decoded: a sink’s records name no place and no instant, and WAI texts say nothing of how an operator identifies a person.
• Training energy, water, standby energy, and any counterfactual (a reference scenario, a saving, an avoided emission).

4. Rules every export follows

1. Classes are never summed. Every energy, carbon or derived figure an export states is the figures of one class. A method field that its method defines as one number over all of a component’s energy is stated once per class present, each marked partial where any other class or any unmetered figure is present. A total of two classes is neither a counter reading nor a model’s output (live-metering §4.5).
2. Unmetered stays unmetered. An unmetered figure is counted, in no row, and never written as zero joules, zero carbon or zero intensity (energy-measurement §2).
3. Partial is marked partial. A row is whole only where every figure of its component is of its class and none is unmetered; otherwise partial, and a partial row MUST NOT be presented as the component’s energy. A form field is supplied only on the same condition over every component it reads, and partial otherwise.
4. Nothing is estimated to fill a gap. A field no record supplies is not_supplied, with its reason (§8.1). No default, typical value, intensity per byte or power model stands in for a figure, and no figure of one class stands in for another.
5. Every figure names its records. Each line, row and field names the records it rests on, by reference (§2), so a reader can recompute it.
6. Carbon only from the operator’s signed, location-based factor table (§6), each factor naming its source by digest; never from a built-in factor. Carbon is a model beside the measured joules (energy-binding §4) and is always stated beside them.
7. No comparison. An export states no baseline, no saving, no avoided emission and no claim about any method’s labels; it compares no figure with any other party’s.
8. Estimates stay apart. An Estimator figure is presented as an estimate. A display’s figure is its own component and is never added to a decode’s (energy-measurement §9.5).

5. WAI’s derived figures: per viewing hour and per gigabyte delivered

5.1 Viewing time

The viewing time V of an export is the sum, over its room sources, of each receipt’s subscriber_us for layer classes 0 to 7 (live-metering §3.3, §4.4): the subscriber-microseconds during which a subscriber session held a media track of the room. It is the receipt’s own unit, recomputed by the receipt’s verifier from the per-hop records (live-metering §5.1 step 8). Layer class 8, a session subscribed to tracks of the room and to none of its media tracks, views nothing: its time is stated apart as events_only_us and is in no denominator. A viewing hour is 3.6 × 10⁹ µs of V.

5.2 Bytes delivered

The bytes delivered D of an export is the sum, over its room sources, over every per-hop record each receipt names, of its ledger entries’ bytes_out (live-metering §3.4): the payload bytes the hops sent the room’s sessions. In a receipt of version 2 it is the receipt’s own bytes_out unit (live-metering §4.4); in a receipt of version 1 it is the same sum, read from the ledgers whose roots the records sign. Bytes a hop sent another hop over a hop link are in no ledger (live-metering §3.10), so a byte is counted once, at the hop that delivered it to a session. A gigabyte is 10⁹ bytes.

5.3 The figures

For each class c among the figures of the export’s delivery_relay, delivery_compositor and delivery_ingest components, let J_c be the sum of their figures of class c, in microjoules. Then:

per viewing hour, class c   = ⌊J_c · 3 600 000 000 / V⌋   µJ per viewing hour
per gigabyte delivered, c   = ⌊J_c · 1 000 000 000 / D⌋   µJ per gigabyte

each stated with its numerator J_c and its denominator V or D, and none at all where the denominator is 0. A figure is whole only where every figure of the three components is of class c and none is unmetered; otherwise it is partial, and is the class-c hops’ energy over the delivery’s viewing time or bytes, not the delivery’s energy per hour or per gigabyte.

5.4 What they are not

• They are the hops’ own energy over their spans, which is largely what running a hop costs whatever it carries, divided by what the hops delivered. They are not the marginal energy of one more viewer or one more byte, and dividing does not make a hop’s energy proportional to either (live-metering §4.6).
• They count no network between hops, no sink and no display (§3.3). A reader MUST NOT present either figure as the energy of watching for an hour or of moving a gigabyte end to end.
• They are one deployment’s figures over its own records, and an export states no comparison of them with anyone’s (§4, rule 7).

6. The factor table

6.1 The record

A factor table is a JSON object (RFC 8259) an operator signs: where its hops’ figures were read (sites), and each grid area’s location-based emission factor over a period (factors), each naming the publication it was taken from by its SHA-256.

Its body is the object without sig. It is signed with Ed25519 (RFC 8032) by signer over wai:energy-factors\x01 ‖ JCS(body), verified as WAI verifies every signature (SPEC §7 Signatures). Its identity, record kind 31, is SHA-256(wai:energy-factors-id\x01 ‖ JCS(body) ‖ signature bytes).

6.2 Rules

A table is refused, factors_invalid, unless: it has exactly these members, of these types; basis is location-based; it has at least one factor; each factor’s region is a region (§2), its scope one of the two, from_us < to_us, mg_co2e_per_kwh at least 1, source 64 hexadecimal digits and source_title 1 to 200 characters, not all of them a space, a tab, a line feed or a carriage return; no two factors of one region and one scope have periods that overlap; each site’s key is 32 B hex, its region a region and from_us < to_us; no two sites of one key overlap; and its signature verifies.

A factor of zero states no factor. A factor without a source cannot be fetched and checked. A market-based factor rests on instruments no WAI record carries, so a table states none.

6.3 A figure’s carbon

For a figure and a scope, its carbon is the first of these that applies:

1. no factor table is given: none, no_factors;
2. the figure is unmetered: none, unmetered;
3. the figure has no span: none, no_span;
4. no site of the figure’s signer overlaps its span: none, no_site; a site overlaps it but none holds the whole span: none, span_split;
5. of the site that holds the span, no factor of its region and the scope overlaps the span: none, no_factor; one overlaps it but none holds the whole span: none, span_split;
6. otherwise the factor that holds it gives ⌊joules_micro · mg_co2e_per_kwh / 3 600 000 000⌋ micrograms of CO2e, and is named by k, its place in factors counted from 0.

A site or factor overlaps a span when its from_us is below the span’s to_us and the span’s from_us below its to_us, and holds it when its from_us is at most the span’s and its to_us at least the span’s. A figure whose span crosses two periods has no carbon: dividing it between them would assume a draw constant over the span, which no record states.

7. The export

An export is a JSON object signed by its exporter. Its body is the object without sig; it is signed over wai:energy-export\x01 ‖ JCS(body), and its identity is SHA-256(wai:energy-export-id\x01 ‖ JCS(body) ‖ signature bytes).

7.1 Sources

An export is computed from a list of sources, each a JSON object whose kind names it:

An export’s sources member lists { "kind", "head" } for each, the head a reference.

A source that is not such an object, whose kind is none of these or whose members are not exactly its kind’s, each of its form, is source_malformed. A sink source gives the session’s segment receipts, at least one, each an object as its session is; one that gives none is source_malformed. A split source’s head is the head: a pair that composes with its tail given as head is refused, source_refused with split_side_mismatch. A source one of whose spans ends past 2⁵³ − 1, or one of whose declared uncertainties is past it, cannot be stated and is source_malformed.

7.2 Figures

Each figure of each source is one line, the sources in the order given; in a room source the hop entries in the receipt’s order; in a sink source its decode, then its display where the session has one; in a split source the head, then the tail.

A source reads its head and the records its figures are stated from: a room source its receipt and each per-hop record the receipt names; a sink source its session receipt and each segment receipt; a split source its two claims. A record that two sources read, or one source twice, is refused, record_duplicate, at the later source: a figure is counted once. The hop records a sink source gives for its origin and relay entries are not read in this sense (§3.1).

7.3 Rows

• units: one row per unit, in this order, each { "unit", "value", "cites" }, value a quantity and cites the heads of the sources it is summed over: viewing_us (V, §5.1), events_only_us, sessions, delivered_bytes (D, §5.2) and traffic_bytes (every ledger entry’s bytes_in and bytes_out) over the room sources; media_us and presented_us over the sink sources; computations, the number of split sources, over them.
• energy: for each component in order, for each class among its metered figures in ascending tag: { "component", "class", "figures", "uj", "max_ppm", "coverage", "delivered_bytes", "traffic_bytes", "cites" }: the figures’ count, an integer, and their sum, a quantity; the largest relative_ppm among them for tags 4 and 5, 0 for tags 2 and 3, an integer; whole or partial by §4 rule 3; for a delivery_* component the sums of its figures’ bytes, quantities, otherwise null; and each figure’s record in line order.
• unmetered: for each component with an unmetered figure, in component order, { "component", "figures", "cites" }: their count and each one’s record.
• carbon: for each energy row and each scope, generation then lifecycle: { "component", "class", "scope", "coverage", "ug", "why", "cites" }. Where every figure of the row has carbon at the scope, ug is their sum and why is null; otherwise ug is null and why is the reason of the first figure, in line order, that has none. Its coverage is the energy row’s, and its cites the energy row’s, then the factor table’s reference where one is given.
• derived: for each class among the delivery_* components’ metered figures, in ascending tag, two rows, per_viewing_hour then per_gigabyte_delivered: { "figure", "class", "coverage", "uj", "over", "value_uj", "cites" }, uj its J_c, over its V or D, value_uj §5.3’s figure or null where over is 0, and cites the figures’ records.

7.4 The CSV

An export’s CSV is its forms, one line per field, under the header method,field,class,status,value,unit,reason,rests_on: each field’s members in that order, null written as nothing, rests_on joined by single spaces. A value holding a comma, a double quote or a line feed is enclosed in double quotes, each double quote in it doubled (RFC 4180). Lines end with a line feed, the last too. The CSV is not signed: it is a rendering of the signed forms, and a verifier recomputes it.

8. The methods

Each method’s form is { "method", "revision", "not_covered", "fields" }: the method’s name, the text read, what of the method this revision could not read (null where it read the text), each exactly as this table writes it, and its fields in the order of its section’s table. An export states the twelve forms in this order.

8.1 Fields

Each field is { "field", "class", "status", "value", "unit", "reason", "rests_on" }. status is supplied, partial or not_supplied; a field that is not supplied has value null and a reason, and one that is has reason null. value is a string or null, and class a class label or null. rests_on names, as strings, the rows it is computed from: energy:<component>:<class>, unmetered:<component>, carbon:<component>:<class>:<scope>, unit:<unit>, period, and factors for the factor table.

A field’s group is the components it reads. A class is present in a group when one of its metered figures has it; the per-class quantities state one field for each present class, in ascending tag, and where none is present, one field of class null, not_supplied, with the reason no_figure where the group has no figure at all and unmetered where all its figures are unmetered (rests_on its unmetered rows). A per-class field’s energy rows are the rows energy:<component>:<class> of its group’s components that have one, in component order. Its quantity is one of:

The status of an E, C, I, CI, Q or P field that states a value is supplied where every figure of the group is of its class and none is unmetered, and partial otherwise. A field’s unit is the unit it is stated in (null for Q, R, F, T and N), also where it is not supplied. A value is a decimal of the unit’s places, floored, with no other rounding: ⌊n · 10^places / divisor⌋ written with its integer part, at least one digit, a point, and exactly places digits:

An intensity is the decimal of its numerator × m over the product of its denominator and its numerator unit’s divisor, at that unit’s places: kWh per viewing hour, kWh per GB and kWh per inference at the places of kWh, over 3 600 000 000 000 times the denominator; gCO2e per viewing hour and gCO2e per GB at the places of gCO2e; and kgCO2e/TB, with m 2⁴⁰, at the places of kgCO2e, a terabyte being 2⁴⁰ bytes as ITU-T L.1333 clause 8 counts it. The floor is taken once, of the whole quotient, in exact integers of any size.

The reasons a field states: no_figure, unmetered, no_record (no WAI record states the quantity, §3.3), embodied, market_based, outside_records (a scenario, an effect or a base year no record states), no_claim (§4 rule 7), no_factors, no_site, no_span, no_factor, span_split, no_denominator, no_uncertainty, average_factor (§8.6).

The groups: delivery is delivery_relay, delivery_compositor, delivery_ingest; data centre is delivery_compositor, delivery_ingest, computation_head; user premises is device_decode, computation_tail; computation is computation_head, computation_tail; operational is every component but device_display.

A split computation’s head is the origin side and its tail the sink side (task-fidelity §5: the work partition between an origin and a sink); that is where a form places them.

8.2 ITU-T L.1333

itu-t-l1333. The KPI is NCIe, network carbon intensity energy (clause 8): the GHG emissions of the electricity of every site of a network, its supporting equipment included (clause 6), over one year (clause 9), per terabyte of the traffic at the network’s user interface (clause 9). WAI meters no equipment of a network in its clause 7 sense. What it supplies is a relay hop’s own energy, a part of the energy of the site it runs in, and the bytes that hop exchanged with the sessions it served, which are traffic at the hop’s user interface. The NCIe it states is that of its relays alone, and partial against the clause.

Clause 8 asks factors that include the supply chain and distribution losses, so the form uses factors of scope lifecycle. The KPI’s period is one year; the form states the export’s.

8.3 ITU-T L.1480

itu-t-l1480. The assessment asks the net second-order effect of an ICT solution against a reference scenario (clause 11), its first-order effects in four parts (11.3.7.1.2) over the life cycle (11.2.4), and a statement of data quality distinguishing primary data, secondary data and estimates (11.4.2). WAI supplies the use stage of parts 1 to 3 where its records meter them, and none of the rest. Since higher-order effects are never supplied, the study’s result is initial guidance (11.5).

8.4 GHG Protocol Scope 2 Guidance

ghg-scope2. The inventory asks scope 2 emissions by the location-based and by the market-based method, each labelled (7.1), from generation-only factors (4.2), with the electricity consumed recommended beside them (7.2). The figures an export holds of an operator’s own consumption are its hops’; a sink’s and a half’s are someone else’s, and are in no field here. A field’s status is about the export’s own figures (§4 rule 3). Against the guidance every figure is a part: a hop’s figure is its counter’s scope, not the site’s metered electricity that scope 2’s activity data is.

8.5 GHG Protocol ICT Sector Guidance

ghg-ict. A service’s footprint per functional unit, its elements reported apart (1.8.8), the use stage in kWh and kgCO2e with the factors stated (1.8.8), factors that include the energy source’s life cycle (1.8.6), shared components allocated by use (1.8.4), and primary and secondary data documented (4.5).

8.6 ISO/IEC 21031 (SCI)

iso-iec-21031. SCI = ((E × I) + M) per R: E the energy of the software boundary in kWh, I a region-specific carbon intensity that excludes market-based measures, M the embodied emissions of its hardware, R the functional unit; disclosed with the boundary and the methodology (Procedure). WAI supplies E and, with a factor table, E × I; it supplies no M, so it states no SCI score, and states the operational part per R. Version 1.0 of the text asks marginal emission rates for I; version 1.1 also admits averages, which is what a location-based factor table states.

8.7 SCI for AI

sci-ai. A consumer score per functional unit of the service (an inference for a classical model), over the operation stage; a provider score over training. WAI’s one computation per split source is one inference over one tensor (task-fidelity §5.4). A claim states no span, so it has no carbon.

8.8 DIMPACT

dimpact. The footprint of serving a digital media product over a period of at least one calendar month, per component: data centre processes (its equation 1, from the owner’s energy data), CDN (supplier energy data, its equations 7 and 8), the internet network (data volume × an intensity, its equation 2), the home router and end-user devices (duration × power, its equation 13), location-based generation-only factors by default. WAI supplies its hops’ energy as the owner’s and supplier’s data, the data volume, and a device’s measured decode energy where the methodology models it; it supplies no network or home router energy, and no intensity per byte stands in for one.

8.9 Greening of Streaming

greening-of-streaming. No reporting format is published. Its public measurement work measures power per component of a delivery chain (encoder, origin and packager, cache, telco, home, end device) with an instrument at a stated sampling interval and resolution. The form states WAI’s figures per those components.

8.10 AFNOR SPEC 2314

afnor-spec-2314. Its public summary states the indicators (climate change, final and primary energy, water, resource depletion, ocean acidification, fine particles, ionising radiation), the functional unit (the AI service to all its users over a year), the life cycle as its boundary, and what a quantitative communication states. The form reads the AI work WAI’s records name as such, the split computations. Not covered: the text itself.

8.11 Blauer Engel DE-UZ 215

de-uz-215. Its criteria measure a software product’s energy on a defined test system as net values above the system’s base load for a standard usage scenario (3.1.1.4), with a meter whose tolerance is stated (3.1.1.2), at least ten runs within a relative standard deviation of 5 % (Annex A 1.1). WAI supplies a sink’s net decode energy (an idle bracket taken off, energy-measurement §3) and a hop’s own, with the declared uncertainty, and none of the scenario statistics.

8.12 UNE 0086:2025

une-0086. Its public scope names energy consumption, carbon footprint, water consumption and performance of an AI system across its life cycle, on premises and in the cloud. Not covered: the text.

8.13 CEN/CLC/TR 18145:2025

cen-clc-tr-18145. Its public scope names an AI system’s operational energy, its other resources (water) and its carbon footprint. Not covered: the text.

9. Verification

A verifier is given the sources, the factor table or none, and the export. It stops at the first refusal, which it reports with its reason and its place, a list:

1. The sources, in order, at ["sources", i], i the source’s place in the list from 0: each reads as its kind (§7.1), else source_malformed; each verifies under its extension, else source_refused, with that extension’s reason beside it.
2. The records, at ["sources", i], i the later source: no record is read twice (§7.2), else record_duplicate.
3. The table, at ["factors"]: it meets §6.2, else factors_invalid.
4. The export, at ["export"]: it is an object of exactly §7’s members, wai_energy_export the integer 1, signer and sig hexadecimal of 32 and 64 bytes, factors and period each an object or null, the other members arrays, and every number in it an integer of §2, else export_malformed; its signature verifies (bad_key, bad_signature).
5. The recomputation: the verifier computes the export’s body again from the sources and the table, with the stated signer. Where the two are equal the export is accepted. Otherwise it goes through the members in the order below and stops at the first that differs. For a member that is a list of rows, the place is the member and i, the first position at which the stated list and the recomputed one differ or only one has a row; a stated row is matched to the recomputed row with the same members named.
   1. sources, then factors: a source or the table that the export does not name as given, not_recomputable, at ["sources"] or ["factors"].
   2. figures, at ["figures", i]. Where both have a line at i, the first of: the recomputed line is the unmetered marker and the stated one has a class or a uj, unmetered_as_zero; at a scope, generation then lifecycle, the stated line states carbon (a ug) and the recomputed one states none or names another factor: carbon_unsourced where no table is given or the stated factor is no place in the table’s factors, and factor_mismatch otherwise, the factor being one of another region, scope or period than the figure’s site, the scope and the figure’s span. Otherwise not_recomputable.
   3. energy, at ["energy", i]. The stated row at i, matched by component and class, is the first of: one whose uj is the matched row’s together with those of one or more of the recomputed rows of its component of other classes, classes_summed; one whose cites name the record of an unmetered figure of its component, unmetered_as_zero; one stated whole whose matched row is partial, partial_as_whole. Otherwise, and where the stated list has no row at i, not_recomputable.
   4. unmetered, at ["unmetered", i]: where an unmetered figure’s record is cited by no stated row of its component, unmetered_as_zero; otherwise not_recomputable.
   5. carbon, at ["carbon", i]. The stated row at i, matched by component, class and scope, is the first of: one stating a ug where no table is given and no matched row states one, carbon_unsourced; one stated whole whose matched row is partial, partial_as_whole. Otherwise not_recomputable.
   6. units, at ["units", i]: where the recomputed row at i is viewing_us or delivered_bytes and the stated row’s value is not the signed sum of §5.1 or §5.2, denominator_mismatch; otherwise not_recomputable. Then derived, at ["derived", i]. The stated row at i, matched by figure and class, is the first of: one whose over is not the matched row’s, denominator_mismatch; one whose uj is the matched row’s together with those of one or more of the recomputed rows of its figure of other classes, classes_summed; one stated whole whose matched row is partial, partial_as_whole. Otherwise not_recomputable.
   7. forms, at ["forms", m], m the first form that differs: where its method, revision, not_covered and number of fields are the recomputed form’s, at ["forms", m, "fields", f], f its first field that differs: one stated supplied that is partial, partial_as_whole; otherwise not_recomputable.
   8. period, at ["period"], and any other difference, at ["export"]: not_recomputable.

An accepted export’s outcome is its identity and its CSV (§7.4).

10. Reasons

A verifier also raises bad_key and bad_signature for the export (SPEC §7 Signatures), and reports a source’s own reason beside source_refused.

11. Conformance

live-conformance/energy-methods/ holds the corpus, one file, vectors.json, written by wai_energy_methods_vectors gen. Its sources are records of the live-metering, sink-energy and machine-coding corpora, read from their committed files; its factor tables and exports are signed from fixed seeds, and its factors are made up for the corpus. Each vector is a list of sources, a factor table or none, an export, and the outcome §9 gives them:

• Accepted: a delivery whose hops are all one class, with carbon at both scopes; a delivery of three classes; a receipt of version 2 whose delivered bytes are its own unit; a delivery with an unmetered hop; the same records with no factor table; a table that leaves every figure without carbon, each for its own reason of §6.3; one export over rooms, sinks of three classes and split computations whole and partial; one with no room; and one with no source at all.
• Refused: each reason of §10 at least once, and both signature codes. The faults of §9 step 5 are each planted in an otherwise correct export that is then signed again, so that its signature is never what refuses it: a figure of another class summed into a row and into a per-viewing-hour figure; an unmetered figure written as zero, counted in a row, and left out of the unmetered rows; carbon with no factor table, in a line and in a row, and carbon naming no factor of the table; a factor of another region, of another period and of another scope; a viewing time that counts layer class 8, a per-viewing-hour figure over the session’s length, and bytes delivered that count bytes received; a figure that is not its record’s, a form field no row gives, another source named, and another period; and a partial row, carbon row, derived figure and form field each stated whole. Before the export is read: a source of another form, a source of each kind that does not verify, a record two sources read, and tables with a factor of zero, a factor with no source, a market-based basis, overlapping periods and sites, and a factor changed after signing.

wai_energy_methods_vectors verify and the test tests/energy_methods.rs check that the file regenerates byte for byte, that wai-rs gives every vector its outcome, that every reason of §10 refuses a vector, that §10 lists exactly the reference’s codes, that §8’s tables are the forms the reference writes, and that a stated outcome changed to another is noticed. live-conformance/energy_methods_verify.py is the second implementation, written from this text: it shares no code with wai-rs, verifies each source with that corpus’s own second implementation (live_metering_verify.py, sink_energy_verify.py, claim_verify.py and machine_coding_verify.py), verifies signatures with WAI’s strict rule written from RFC 8032 (claim-conformance/_ed25519.py), reads the forms and their fields from §8’s tables as this text writes them, recomputes every export itself, gives every vector the same outcome and CSV, requires every mutated copy of the corpus to fail, and runs once with each of its checks dropped, each such run failing on the corpus.

12. Security and privacy considerations

• An export restates what signed records state. Its signature makes the export attributable to its exporter; the figures remain their signers’ statements, and their classes say how they were obtained (energy-measurement §5). A verifier recomputes every row from the records, so an exporter cannot state a figure no record states.
• A factor table states where an operator’s hops ran, by region and period. An operator that gives its table to a reader discloses that.
• An export names no person: a sink’s session is random per viewing session (sink-energy §10), and the units are sums over sessions. A room’s units are its receipt’s, which a deployment that publishes a receipt already publishes.