beamed-power-interface

§6 BPI-M — Metering and Settlement

6.1 Metering points

[R-M-001] Both segments SHALL declare their metering points, each with a name, a one-line-diagram reference, and the physical boundary it represents.

Point Owned by Definition
Revenue metering point Receiving The named electrical boundary at which delivered energy is settled — typically the medium-voltage terminals of the power conversion system, or a declared DC bus
Check metering point Receiving Optional independent second meter
Radiation point Space RF output of the antenna, or DC input to the amplifier chain — stated which

[R-M-002] The settled quantity SHALL be the receiving-side delivered energy at the revenue metering point.

Rationale: that is what the customer actually receives. The space-side figure is not a competing truth — it exists to bound disputes and to compute end-to-end efficiency.

6.2 Sampling, aggregation and meter class

[R-M-010] Interior samples SHALL be taken at 1 Hz at each declared metering point, timestamped per §2.2.

[R-M-011] Energy SHALL be aggregated both per delivery window and into the receiving segment’s declared settlementIntervalMin.

A LEO delivery window is 1.5–3 minutes, shorter than any electricity market interval. A supplier delivering four windows inside one 15-minute interval must be able to produce both views, because one is the physics and the other is how the money moves.

[R-M-012] A revenue meter SHALL be of accuracy class 0,1 S, 0,2 S or 0,5 S per IEC 62053-22:2020, or 0.1, 0.2 or 0.5 per ANSI C12.20, and the record SHALL carry its class, the standard and edition the class is claimed under, its serial number, and its calibration certificate date.

[R-M-014] A meter accuracy class SHALL NOT be presented as evidence that a particular meter’s readings are valid for trade. The record SHALL carry the legal metrology basis separately, or declare that it holds none.

Why [R-M-014] exists, and it is the useful half of this section. IEC 62053-22:2020 states that it “applies to their type tests only”. A type test establishes that a design of meter meets a class in a laboratory. Whether this meter, in this cabinet, on this date, produces readings admissible for settlement is a different question, governed by national legal metrology — the Measuring Instruments Directive in Europe, state regulation in the United States, and their equivalents elsewhere. A specification that let an implementer write “class 0,2 S” and consider the matter closed would be inviting exactly the wrong inference at exactly the point where money changes hands.

Two further consequences of the same reading, worth stating because they are easy to miss:

[R-M-013] Every value in the settled energy path SHALL carry provenance per §2.6.

6.3 The MeteringRecord

MeteringRecord {
  recordId, commitmentId, sessionId, window { start, end },
  delivered  { energy_kWh, _prov, meteringPointRef,
               meterClass, meterSerial, calibrationDate },
  transmitted{ energy_kWh, _prov, radiationPointRef },
  efficiency { value, numeratorPoint, denominatorPoint, pathLength_m, _prov },
  samples[]  { t, receivedPower_kW, transmittedPower_kW, elevationDeg,
               rainRate_mmh, _prov },
  settlementIntervals[] { start, end, energy_kWh },
  nonDelivery[]{ start, end, energy_kWh_shortfall, causeCode, bearer,
                 evidenceRef, disputed },
  atmosphericConditions { modelRefs[], source, _prov },
  attestationRef, sessionLogRef,
  signatures[] { role, org, keyId, sig, signedAt }
}

[R-M-020] A record is settleable only when it carries signatures from two opposing roles and the two independent energy figures reconcile within the declared tolerance:

| E_delivered − E_transmitted × η_expected |  ≤  tolerance

[R-M-021] η_expected SHALL be computed from the declared propagation models using the actual elevation and weather over the window. A nameplate efficiency SHALL NOT be used.

[R-M-022] A record containing any estimated or declared value in the settled energy path SHALL NOT settle without explicit countersignature of that specific field by both parties.

[R-M-023] efficiency SHALL name both endpoints and the path length, per [R-C-010]. A bare efficiency figure is invalid.

The motivation this rule used to carry was wrong, and the correction is more useful than the original. An earlier draft set Xidian’s 20.8% DC-to-DC at 100 m against Virtus Solis’s ARPA-E target of ≥70% “source to delivered DC” at 200 m and called them incomparable. The first external comment this specification received pointed out that if “source to delivered DC” means DC in to DC out, those are the same measurement class, and DOE’s description of the target as roughly a 4× improvement on the best DC-to-DC systems to date is internally consistent. That comment was correct. See DISPOSITIONS.md C-1.

What survives the correction is narrower and is the actual reason this requirement exists. Those two results were obtained with a 4 m transmitter into a 4 m receiver at 200 m, and a 1.2 m transmitter into a 5.2 m rectenna at 100 m. Beam coupling depends on the aperture-range product, so two figures of the same measurement class still do not separate component efficiency from coupling geometry. Naming the endpoints and the path length is a partial answer to that and is in force today.

It is not the right answer. The literature already carries a subsystem decomposition whose stage efficiencies multiply to the total, published expressly to establish a common nomenclature for assessing power beaming systems — Power Beaming: History, Theory, and Practice (Jaffe, Nugent, Strassner II and Szazynski, World Scientific, 2024). Under a decomposition, coupling is one stage, so declaring the chain declares the geometry’s effect without a separate rule about apertures. [R-M-023] and [R-C-010] will be rewritten for 0.2 to profile that method rather than to invent a parallel one, and are deliberately not being rewritten from a summary: this project does not carry a method it has not read. Recorded as OBJECTIONS.md O-10.

6.4 Non-delivery attribution

[R-M-030] Every second of shortfall inside a committed window SHALL be attributed to a cause code.

Each code carries a default cost bearer. The default is a starting point for a commercial agreement, which may override it; BPI’s job is to make the attribution a matter of record, not to decide who pays.

Cause Default bearer
WEATHER_BELOW_RATE_FLOOR Neither — shared
AVIATION_TRANSIT Receiving
PERSON_INTRUSION Receiving
RECEIVER_PLANT_TRIP Receiving
GRID_CURTAILMENT Receiving
SPACE_FAULT Space
POINTING_LOSS Space
EFFICIENCY_ANOMALY Space
CONJUNCTION_MANOEUVRE Space
REGULATORY_ORDER Neither
TOKEN_EXPIRY Determined from evidence — see below
SCHEDULED_END n/a

[R-M-031] Where the cause is TOKEN_EXPIRY, both segments SHALL produce their SessionLog covering ±60 s around the event, and the bearer SHALL be determined from the hash-chained seq on both sides.

Whether the receiving segment stopped issuing or the space segment stopped receiving is a question of fact. Because the chain is signed and sequential, it is answerable from artefacts created before anyone knew there would be money at stake — which is the only kind of evidence worth having.

[R-M-032] A SessionLog SHALL be produced by both segments for any session containing a non-nominal event, at 1 Hz, signed, and retained for the period declared in capability.

6.5 Dispute ladder

[R-M-040] Disputes SHALL be resolved in this order, declared in advance so that no discretion is exercised at settlement time:

  1. The receiving-side revenue meter, if its calibration certificate is current per the declared interval.
  2. The check meter, if declared and independently calibrated.
  3. Reconstruction from the 1 Hz telemetry against the declared atmospheric model. The result is flagged derived and therefore requires countersignature per [R-M-022].
  4. Independent re-measurement by a mutually named third party.
  5. The dispute mechanism of the commercial agreement.

Steps 1–3 are this specification’s job. Step 5 is not, and BPI defines nothing about it beyond leaving the seam clean.