{
 "about": "M2 (On or off? Unit commitment as a mixed-integer program). Prairie Town's fleet from lesson 0 (town.json) on 29 July 2025, the 2025 summer day with the highest hourly demand on the Southwest Power Pool grid (EIA-930 shapes in town_days.json, key summer_peak), scaled to the town exactly as lesson 0 scales its day (grid-operator.js prepare(): wind and solar = shape x farm size, rounded; demand = shape x 450 MW, rounded so that the need left for gas is a multiple of 5 MW). The switching data of the two gas plants (minimum output, no-load and start-up costs, minimum run and down times, states before and after the day) and the unserved-energy penalty are illustrative. The reference block is precomputed with the vendored HiGHS (labelled precomputed where the page shows it before a solve); _tests/learn/test_m02-unit-commitment.js re-solves every number in it.",
 "accessed": "2026-11-03",
 "day": {
  "date": "2025-07-29",
  "label": "29 July 2025",
  "note": "the 2025 summer day with the highest hourly demand, among days with no repaired hours",
  "units": "MW, hour by hour (local time, Central daylight time)",
  "demand": [337, 321, 311, 302, 298, 302, 310, 321, 338, 360, 384, 407, 423, 426, 442, 452, 449, 449, 445, 434, 420, 400, 380, 354],
  "wind": [117, 116, 111, 107, 103, 102, 94, 81, 53, 40, 33, 30, 35, 42, 47, 50, 51, 55, 64, 75, 86, 105, 110, 109],
  "solar": [0, 0, 0, 0, 0, 0, 1, 35, 125, 160, 181, 177, 173, 159, 160, 157, 163, 139, 111, 54, 4, 0, 0, 0]
 },
 "fleet": {
  "nuclear": {
   "label": "Nuclear plant",
   "short": "Nuclear",
   "mw": 100,
   "cost": 10,
   "flat": true,
   "color": "var(--lx-nuc)"
  },
  "wind": {
   "label": "Wind farm",
   "short": "Wind",
   "mw": 150,
   "cost": 0,
   "color": "var(--lx-wind)"
  },
  "solar": {
   "label": "Solar farm",
   "short": "Solar",
   "mw": 200,
   "cost": 0,
   "color": "var(--lx-solar)"
  },
  "cc": {
   "label": "Gas combined-cycle plant",
   "short": "Gas CC",
   "mw": 150,
   "cost": 40,
   "min": 50,
   "noload": 300,
   "startup": 8000,
   "up": 6,
   "down": 6,
   "init": 1,
   "end": 1,
   "color": "var(--lx-cc)"
  },
  "pk": {
   "label": "Gas peaker",
   "short": "Peaker",
   "mw": 100,
   "cost": 100,
   "min": 30,
   "noload": 300,
   "startup": 2000,
   "up": 2,
   "down": 2,
   "init": 0,
   "color": "var(--lx-pk)"
  }
 },
 "fleet_note": "min = minimum output when on (MW); noload = $ per hour on; startup = $ per start; up and down = minimum run and down times (hours); init = on (1) or off (0) before the day; end = state required in the last hour. All illustrative; the peaker's 30 MW minimum is lesson 11's.",
 "penalty": 3000,
 "penalty_note": "Cost per MWh of unserved demand: a large illustrative number, as in lesson 11, so that every node of the branch-and-bound tree has an answer.",
 "lesson": {
  "focus": 17,
  "edit": [15, 16, 17, 18, 19, 20, 21, 22, 23],
  "stair": {
   "hour": 23,
   "max": 10,
   "step": 0.5
  },
  "check": [18, 20]
 },
 "reference": {
  "label": "precomputed with HiGHS 1.15 (the steps above solve the same models live)",
  "focus": 17,
  "lp": 159500,
  "lpFocus": 5,
  "lpHigh": "17:00–22:00",
  "relax": 168975,
  "relaxFocus": "5%",
  "relaxFocusSw": "0.05",
  "relaxStarts": "0.8",
  "milp": 173200,
  "peakerOn": "17:00–22:00",
  "condPrices": [40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 100, 100, 100, 40, 40],
  "condHigh": "19:00–21:00",
  "uplift": 9200,
  "settle": {
   "pk": {
    "revenue": 21600,
    "cost": 30800,
    "running": 27000,
    "noload": 1800,
    "startup": 2000,
    "energyShort": 5400
   },
   "cc": {
    "revenue": 138200,
    "cost": 118400,
    "profit": 19800
   }
  },
  "stair": [0, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 1700, 2340, 2360, 2380, 2400, 2420, 2440, 2460, 2480, 2500],
  "stairShed": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0.5, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  "stairPk": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1],
  "stairCross": 5.71,
  "tree": {
   "lps": 11,
   "branchings": 5,
   "rootFrac": 6,
   "nodes": [
    {
     "id": 0,
     "parent": null,
     "by": null,
     "val": null,
     "bound": 168975,
     "status": "branched",
     "shed": 0
    },
    {
     "id": 1,
     "parent": 0,
     "by": "u_pk_19",
     "val": 0,
     "bound": 328920,
     "status": "pruned",
     "shed": 55
    },
    {
     "id": 2,
     "parent": 0,
     "by": "u_pk_19",
     "val": 1,
     "bound": 169510,
     "status": "branched",
     "shed": 0
    },
    {
     "id": 3,
     "parent": 2,
     "by": "u_pk_21",
     "val": 0,
     "bound": 300695,
     "status": "pruned",
     "shed": 45
    },
    {
     "id": 4,
     "parent": 2,
     "by": "u_pk_21",
     "val": 1,
     "bound": 169735,
     "status": "branched",
     "shed": 0
    },
    {
     "id": 5,
     "parent": 4,
     "by": "u_pk_18",
     "val": 0,
     "bound": 242160,
     "status": "pruned",
     "shed": 25
    },
    {
     "id": 6,
     "parent": 4,
     "by": "u_pk_18",
     "val": 1,
     "bound": 170575,
     "status": "branched",
     "shed": 0
    },
    {
     "id": 7,
     "parent": 6,
     "by": "u_pk_22",
     "val": 0,
     "bound": 228515,
     "status": "pruned",
     "shed": 20
    },
    {
     "id": 8,
     "parent": 6,
     "by": "u_pk_22",
     "val": 1,
     "bound": 171415,
     "status": "branched",
     "shed": 0
    },
    {
     "id": 9,
     "parent": 8,
     "by": "u_pk_17",
     "val": 0,
     "bound": 185900,
     "status": "integer",
     "shed": 5
    },
    {
     "id": 10,
     "parent": 8,
     "by": "u_pk_17",
     "val": 1,
     "bound": 173200,
     "status": "best",
     "shed": 0
    }
   ],
   "first": {
    "t": 19,
    "x": 0.55
   },
   "last": {
    "t": 17
   },
   "firstOff": {
    "bound": 328920,
    "shed": 55
   },
   "firstPlan": 185900,
   "firstPlanShed": 5,
   "prunedByFirst": 4
  }
 },
 "sources": {
  "eia-930": {
   "text": "EIA, Hourly Electric Grid Monitor (Form EIA-930), Southwest Power Pool",
   "url": "https://www.eia.gov/electricity/gridmonitor/",
   "asOf": "2025 data, accessed 2 November 2026"
  },
  "ferc-primer": {
   "text": "FERC staff, Energy Primer: A Handbook of Energy Market Basics (April 2020), p. 55: day-ahead unit commitment",
   "url": "https://www.ferc.gov/sites/default/files/2020-06/energy-primer-2020_0.pdf",
   "asOf": "April 2020 edition; checked 3 November 2026"
  },
  "ferc-844": {
   "text": "FERC Order No. 844, Uplift Cost Allocation and Transparency in Markets Operated by RTOs and ISOs, 163 FERC ¶ 61,041 (issued 19 April 2018), P 7",
   "url": "https://www.ferc.gov/sites/default/files/2020-06/Order-844.pdf",
   "asOf": "checked 3 November 2026"
  },
  "oneill-2005": {
   "text": "O'Neill, Sotkiewicz, Hobbs, Rothkopf and Stewart (2005), Efficient market-clearing prices in markets with nonconvexities, European Journal of Operational Research 164(1), 269-285",
   "url": "https://doi.org/10.1016/j.ejor.2003.12.011",
   "asOf": "checked 3 November 2026"
  },
  "knueven-2020": {
   "text": "Knueven, Ostrowski and Watson (2020), On Mixed-Integer Programming Formulations for the Unit Commitment Problem, INFORMS Journal on Computing",
   "url": "https://doi.org/10.1287/ijoc.2019.0944",
   "asOf": "checked 3 November 2026"
  },
  "highs": {
   "text": "HiGHS, open-source linear and mixed-integer solver (documentation; option mip_rel_gap, default 0.0001)",
   "url": "https://ergo-code.github.io/HiGHS/dev/",
   "asOf": "solver 1.15 in the browser; checked 3 November 2026"
  }
 }
}