{
  "_provenance": {
    "fitted_by": "energy-biophysical-economics seat, memo-03, reply to d021",
    "primaries": [
      "DOE LPT Resilience Report to Congress 2024 (md5 89c09245f41fac3e62582a6ff1487393)",
      "DOE Large Power Transformers and the U.S. Electric Grid, April 2014 update"
    ],
    "class_boundary_flags": [
      "production/base figures: LPT >=100 MVA",
      "demand series: >60 MVA \u2014 growth rates transferable, LEVELS are not",
      "750 (>60 MVA demand 2019) vs 754 (LPT-class supply 2019) is a numerical coincidence across classes \u2014 never conflate"
    ]
  },
  "age_structure": {
    "anchor_year": "2014 survey vintage",
    "form": "gamma(years)",
    "central": {
      "k": 3.047,
      "theta": 12.798,
      "check_P_ge_25": 0.7,
      "diag_P_ge_70": 0.0945
    },
    "corners": {
      "mean38_q0.65": {
        "k": 2.413,
        "theta": 15.747,
        "check_P_ge_25": 0.65,
        "diag_P_ge_70": 0.1037
      },
      "mean38_q0.75": {
        "k": 4.563,
        "theta": 8.328,
        "check_P_ge_25": 0.75,
        "diag_P_ge_70": 0.0547
      },
      "mean40_q0.65": {
        "k": 2.068,
        "theta": 19.344,
        "check_P_ge_25": 0.65,
        "diag_P_ge_70": 0.1335
      },
      "mean40_q0.75": {
        "k": 3.819,
        "theta": 10.474,
        "check_P_ge_25": 0.75,
        "diag_P_ge_70": 0.0855
      }
    },
    "upgrade": "EIA-860 vintage pull replaces this fit wholesale (N_a(0) direct) and enables cohort hazard"
  },
  "hazard": {
    "form": "weibull replacement hazard",
    "beta_band": [
      2.5,
      4.5
    ],
    "eta_band": [
      55.0,
      75.0
    ],
    "central": {
      "beta": 3.5,
      "eta": 65.0
    },
    "diagnostics": {
      "central": {
        "beta": 3.5,
        "eta": 65.0,
        "median_life_yr": 58.5,
        "P_survive_40": 0.833,
        "P_survive_70": 0.274,
        "fleet_avg_hazard_pct_yr": 2.33,
        "implied_replacements_per_yr_on_4900_6799": [
          114,
          159
        ]
      },
      "lo": {
        "beta": 2.5,
        "eta": 75.0,
        "median_life_yr": 64.8,
        "P_survive_40": 0.812,
        "P_survive_70": 0.431,
        "fleet_avg_hazard_pct_yr": 1.36,
        "implied_replacements_per_yr_on_4900_6799": [
          66,
          92
        ]
      },
      "hi": {
        "beta": 4.5,
        "eta": 55.0,
        "median_life_yr": 50.7,
        "P_survive_40": 0.788,
        "P_survive_70": 0.052,
        "fleet_avg_hazard_pct_yr": 6.45,
        "implied_replacements_per_yr_on_4900_6799": [
          316,
          439
        ]
      }
    },
    "boundary": "replacement hazard (failure + age-retirement), not catastrophic-failure-only; shock removals are the engine's separate pulse stream"
  },
  "demand": {
    "level_anchor_LPT_class_2019_units": 754,
    "level_anchor_boundary": ">=100 MVA, US-bound supply 2019 (137+617) used as demand proxy [stated approximation]",
    "growth_rate_source_boundary": ">60 MVA class (DOE 750@2019 -> 900@2027)",
    "g_central_per_yr": 0.0231,
    "floor_band_g_per_yr": [
      0.015,
      0.03
    ],
    "coupled_boom": {
      "g_per_yr_band": [
        0.05,
        0.1
      ],
      "window": "2024-2032 [ASSUMED]",
      "order_intake_surge_multiplier_band": [
        1.1,
        1.4
      ],
      "surge_note": "the 70% y/y is ORDER INTAKE (incl. backlog-race and double-ordering), not underlying demand \u2014 modeled as a transient arrival multiplier, mean-reverting; NOT a demand growth rate"
    },
    "ltra_flag": "DOE spread suffices for floor+central at build-start; NERC LTRA pull REQUIRED before the phase diagram / coupled band renders"
  },
  "capacity": {
    "domestic_nameplate_2019_units_yr": 343,
    "domestic_actual_2019_units_yr": 137,
    "utilization_2019": 0.4,
    "util_consistency_check": 0.399,
    "import_2019_units_yr": 617,
    "import_baseline_growth_band_per_yr": [
      0.0,
      0.02
    ],
    "ramp_cap": {
      "r_max_per_yr_band": [
        0.15,
        0.3
      ],
      "basis": "ESTIMATED \u2014 skill-formation physics: winding/assembly/test proficiency ~2-4 yr apprenticeship; sustainable mentor ratio ~1-2 trainees/master; primary evidence that personnel limit capacity: DOE 2014 ('availability of trained personnel set limits', line 1053)",
      "applies_to": "utilization recovery toward nameplate AND staffing of new lines; DPA relaxes project DELAYS, not the skill cap"
    },
    "expansion_paths": {
      "frozen": "nameplate 343 fixed; utilization free under ramp cap",
      "announced": "Cox-notes expansions (Virginia Transformer, Hitachi, Siemens) \u2014 SECONDARY, capacity increments TO PRIMARY before coupled-band render; timing band announcement->first unit 30-48 mo, +12-24 mo to rated [ASSUMED]",
      "dpa": "announced minus 12-18 mo on project delays [ASSUMED]; skill cap unchanged"
    }
  },
  "build_time": {
    "LPT": {
      "form": "lognormal(months)",
      "central": {
        "mu": 2.1972,
        "sigma": 0.3448,
        "median_mo": 9.0,
        "p90_mo": 14.0
      },
      "median_band_mo": [
        7.0,
        11.0
      ],
      "sigma_band": [
        0.25,
        0.45
      ],
      "anchor": "2010 slack-market 5-12 mo domestic / 6-16 foreign (DOE 2014 \u00a73.1.4)"
    },
    "distribution_class": {
      "form": "lognormal(months) PLACEHOLDER",
      "median_band_mo": [
        1.0,
        3.0
      ],
      "tag": "ASSUMED \u2014 the two DOE primaries are LPT-only (2024 report \u00a7: 'not distribution transformers'); needs its own primary before the distribution-class run (which is queued second per d020)"
    }
  },
  "calibration": {
    "DO_NOT_INPUT": true,
    "target": "36 mo commonly quoted, 60 mo max (DOE 2024); pre-COVID <1 yr",
    "corridor_backlog_units": {
      "at_36mo": [
        1462,
        1912
      ],
      "at_60mo": [
        2762,
        3612
      ],
      "basis": "Q ~= (quoted lead - B_central) x throughput; C band 650-850/yr spans US-bound supply 2019 +-13%; ILLUSTRATIVE consistency corridor derived FROM the target \u2014 using it as an input would be circular, so it is a check, never a parameter"
    }
  }
}