Billing quantities

Arbeitsmenge, Spitzenleistung and Benutzungsstundenzahl; tariff registers and § 14a Modul 3; Blindmehrarbeit, Mehr-/Mindermengen, network losses and the annual forecast.

Quantities only — kWh, kW, kvarh, hours; prices are the Preisblatt's.

Arbeitsmenge and Spitzenleistung

aggregate(&series, period) sums the billable intervals in the period and takes the Spitzenleistung as the highest average power of one of them, kWh × 3600 ÷ s — the Jahreshöchstleistung of § 17 Abs. 2 StromNEV. On a grid coarser than an hour or a non-energy channel it is None.

use metering::prelude::*;
use time::{Duration, macros::date};

let day = DayBoundary::Strom.day(date!(2026 - 06 - 01)).unwrap();
// The evening's last six hours never arrived.
let slots = (0..72)
    .map(|i| MeterInterval::quarter_hour(day.start() + Duration::minutes(15 * i), dec!(0.5), QualityFlag::Measured))
    .collect::<Result<Vec<_>, _>>().unwrap();
let series = Series::new(Resolution::QUARTER_HOUR, DayBoundary::Strom, slots).unwrap();

let period = aggregate(&series, day).unwrap();
assert_eq!(period.arbeitsmenge, dec!(36));
assert_eq!(period.spitzenleistung_kw, Some(dec!(2)));
assert_eq!(period.spitzenleistung_at, Some(day.start()));
assert_eq!(period.coverage.pct(), Some(dec!(75))); // of the declared day

Coverage is against the declared period. Import and export are two channels, so two calls; sum_by_direction balances intervals by the direction their OBIS code names.

Benutzungsstundenzahl — BillingPeriod::benutzungsdauer_h(), Arbeitsmenge ÷ Spitzenleistung, cut to BENUTZUNGSDAUER_DP (§ 17 Abs. 1 StromNEV, Anlage 4). StromNEV expires on 31.12.2028 (STROMNEV_AUSSERKRAFT); nothing gates on the date.

Tariff registers

A Zaehlzeitdefinition is ordered windows over months × day group × local time band, each naming a register, with a fallback — the Zweitarif, § 14a Modul 3, or any definition transmitted over UTILTS. in_land books the Land's holidays as Sundays.

§ 14a Modul 3

HT, NT and ST, mandatory for every Netzbetreiber from 1 April 2025 (BNetzA BK8-22/010-A). HT/NT may be restricted to single quarters (BDEW AWH Modul 3 v1.1, § 2: "Der Netzbetreiber hat das Wahlrecht, den Gültigkeitszeitraum auf einzelne Quartale zu beschränken"); outside them everything books into ST.

use metering::billing::zaehlzeit::{
    HT, NT, ST, Modul3Conformance, Modul3Context, Quarter, Zaehlzeitdefinition, assess_modul_3,
};
use metering::time::holiday::Bundesland;
use time::macros::{date, datetime};

let zzd = Zaehlzeitdefinition::modul_3(
    "NB-14A-3",
    date!(2026 - 01 - 01),
    (17 * 60, 20 * 60), // HT 17:00–20:00 local
    (22 * 60, 6 * 60),  // NT 22:00–06:00, across midnight
    &[Quarter::Q1, Quarter::Q4],
)
.unwrap()
.in_land(Bundesland::Nw)
.until(date!(2026 - 12 - 31));

assert_eq!(zzd.register_for(datetime!(2026-01-05 17:00 UTC)), Some(HT)); // 18:00 MEZ
assert_eq!(zzd.register_for(datetime!(2026-01-05 2:00 UTC)), Some(NT));
assert_eq!(zzd.register_for(datetime!(2026-07-06 16:00 UTC)), Some(ST)); // Q3

let assessment = assess_modul_3(&zzd, &Modul3Context::new().at_a_conforming_delivery_point());
assert_eq!(assessment.verdict, Modul3Conformance::Conforms);

assess_modul_3 checks the AWH rules — three reachable registers covering every instant, HT ≥ 2 h on every day class, identical windows across whole billed quarters, at least two, one calendar year — and the Modul3Context preconditions (Modul 1, iMSys, no RLM). An unstated precondition is Unknown. Price corridors and the publication deadline are not checked.

Splitting energy

split_energy books each billable interval into its register; Σ per_register + Σ straddling + Σ unassigned is the billable energy exactly. An interval across a band boundary is straddling.

use metering::billing::zaehlzeit::{HT, Zaehlzeitdefinition};
use metering::{MeterInterval, QualityFlag};
use rust_decimal::dec;
use time::macros::{date, datetime};

let zzd = Zaehlzeitdefinition::ht_nt("NB-1", date!(2026 - 01 - 01), 6 * 60, 22 * 60).unwrap();
let midday = MeterInterval::quarter_hour(datetime!(2026-01-05 9:00 UTC), dec!(3), QualityFlag::Measured).unwrap();
// An hour across 06:00 local holds both registers.
let across = MeterInterval::hour(datetime!(2026-01-05 4:30 UTC), dec!(1), QualityFlag::Measured).unwrap();

let split = zzd.split_energy(&[midday, across]).unwrap();
assert_eq!(split.per_register[HT], dec!(3));
assert_eq!(split.straddling.len(), 1);
assert!(!split.is_complete());

Blindmehrarbeit

Blindmehrarbeit = max(0, Blindarbeit − ratio × Wirkarbeit). The ratio is the Netzbetreiber's (§ 17 Abs. 1 StromNEV); ReactiveLimit::HALF and COS_PHI_0_9 are the published practice, neither a default.

use metering::billing::reactive::{ReactiveBalance, ReactiveLimit};
use rust_decimal::dec;

let b = ReactiveBalance::new(dec!(100000), dec!(62000), ReactiveLimit::HALF).unwrap();
assert_eq!(b.blindmehrarbeit_kvarh(), dec!(12000.0));

let strict = ReactiveBalance::new(dec!(100000), dec!(62000), ReactiveLimit::COS_PHI_0_9).unwrap();
assert_eq!(strict.blindmehrarbeit_kvarh(), dec!(13570.0000));

Mehr-/Mindermengen, losses, forecast