{ "about": { "what": "Engine E3's settings and costs: Prairie City's energy hub (the three districts behind their substation limits) as a linear program over prairie-city.json's eight representative days. Prairie City's own numbers are in prairie-city.json; this file holds only what the engine adds.", "line": "Prairie City is fictional; its numbers are illustrative.", "built": "2026-11-06", "builtBy": "scripts/build_learn_e3_data.py (ResearchPortfolio repository): python3 scripts/build_learn_e3_data.py --site ; the `precomputed` block is written by the tests' --write mode", "set": "Costs read from other course files say so in `via`; everything marked \"teaching\" is illustrative, set for this course, with a range the reader can change." }, "dollarYear": 2025, "finance": { "rate": 0.04, "plantLife": 30, "note": "Every up-front cost is paid as a yearly amount: the up-front cost x the capital recovery factor at a 4% real rate over the item's life, plus its upkeep. 4% real is lesson 13's rate (a round value inside the 2025 ATB's financing range).", "via": "13-capstone.json finance", "src": [ "atb2025-fin" ] }, "heatPump": { "capex": 7355, "capexSource": 6730, "capexYear": 2022, "life": 15, "note": "EIA's minimum-efficiency air-source heat pump, installed, per home ($6,730 in 2022 dollars, x 1.0928 to 2025 dollars with EIA's GDP deflator, as engine E0 does); 15-year life. Its efficiency through the year is Prairie City's COP curve (prairie-city.json, cop), not this unit's rating. Commercial buildings are counted as home-equivalents by their heat need.", "via": "e0.json home.hp.standard", "src": [ "eia-aeo2026-rdm", "eia-steo-9a" ] }, "retrofit": { "cost": { "def": 9000, "lo": 3000, "hi": 25000, "step": 500 }, "save": { "def": 18, "lo": 10, "hi": 50, "step": 1 }, "life": 30, "anchor": { "gasCut": 17.8, "costPerHome": 4695, "costYear": 2008, "programYear": 2008 }, "note": "Set for teaching: an envelope package (air sealing, attic and wall insulation, duct sealing) that cuts a home's space-heat need by the share you set, at a cost per home you set (2025 dollars), lasting 30 years. For scale: ORNL's national evaluation of DOE's Weatherization Assistance Program found that gas-heated single-family homes weatherized in program year 2008 cut their gas use by 17.8%, at an average cost of $4,695 a home in 2008 dollars (not converted here).", "set": "teaching", "src": [ "ornl-wap-2014" ] }, "dh": { "network": { "cost": { "def": 12000, "lo": 5000, "hi": 25000, "step": 500 }, "life": 40 }, "plant": { "cop": 3, "capex": { "def": 1200, "lo": 600, "hi": 2000, "step": 50 }, "life": 25, "boilerEff": 0.9 }, "store": { "capex": { "def": 3000, "lo": 1000, "hi": 8000, "step": 250 }, "life": 30, "lossPerHour": 0.005, "minHours": 4 }, "loss": 0.1, "note": "Set for teaching: a hot-water network in the dense core; each connected home-equivalent costs the network sum you set (pipes and connections, 40 years); 10% of the heat sent out is lost in the pipes. The plant is a large electric heat pump on a steady heat source (COP 3.0 every hour, fed through the core's substation; cost per kW of heat, 25 years) with a gas boiler (90%) for the rest, which is assumed to exist already and is counted at its fuel only. The store is a water tank: cost per MWh of heat it holds (30 years), 0.5% of its heat lost each hour, filled or emptied in 4 hours or more.", "set": "teaching" }, "ev": { "minHours": 6, "note": "Managed charging moves each day's charging energy to any hour of the same day, at most one sixth of it in one hour (a day's charge takes 6 hours or more): it assumes cars can plug in at home or at work. Unmanaged charging follows prairie-city.json's evening profile. Vehicles' prices are outside the boundary: only their fuel and electricity are counted.", "set": "teaching" }, "rooftop": { "capex": 4738, "capexSource": 4336, "capexYear": 2022, "fom": 20, "life": 25, "note": "EIA's residential solar system, installed, per kW ($4,336 in 2022 dollars, x 1.0928 to 2025 dollars, as engine E0 does); upkeep $20 per kW a year (illustrative, E0's); 25-year life. Output per MW follows prairie-city.json's solar shape on each day, scaled to EIA's 17.6% rooftop capacity factor.", "via": "e0.json home.pv", "src": [ "eia-aeo2026-rdm", "eia-steo-9a", "eia-dg-2024" ] }, "battery": { "capex": 1371, "fomShare": 0.04, "life": 15, "hours": 4, "rte": 0.85, "note": "Neighbourhood batteries at the substations, 4 hours: NREL's 2024 cost ($372 per kW plus $241 per kWh, 2024 dollars, x 1.0263 to 2025 dollars with BEA's deflator, as capstone C2 does), 4% of it a year of upkeep, 15 years; 85% of a charge comes back (the loss is taken on charging).", "via": "e2-plains-grid.json c2.costs.bat; e0.json farm.battery.rte", "src": [ "nrel-battery-2025", "bea-nipa-119", "eia-aeo2026-emm" ] }, "upgrade": { "capex": { "def": 800, "lo": 200, "hi": 2000, "step": 50 }, "life": 40, "note": "Set for teaching: more room at a district's substation (a transformer and feeders), an up-front cost per kW you set, paid over 40 years. The model buys only what the busiest hour needs after every flexible load has moved.", "set": "teaching" }, "tie": { "peak": 20, "cityPeak": 10, "wear": 1, "storeWear": 0.5, "ev": 0.1, "note": "Stated small costs, far below any real one, that pick one plan when several cost the same: $20 a year per MW of each district's busiest hour, $10 per MW of the three districts' busiest hour together, $1 per MWh out of a battery, $0.50 per MWh out of the heat store, and $0.10 per MWh of managed charging times the hour's share of SPP's peak demand (charging prefers quieter hours). They are left out of every reported cost." }, "c3": { "budget": { "def": 1500, "unit": "$ million up front, 2026 to 2040", "set": "teaching" }, "wind": { "capex": 1712, "fom": 34.57, "life": 30, "via": "13-capstone.json techs.wind", "src": [ "eia-aeo2026-emm" ] }, "solarFarm": { "capex": 1484, "fom": 23.6, "life": 30, "via": "13-capstone.json techs.solar", "src": [ "eia-aeo2026-emm" ] }, "electrolyzer": { "capex": 2186, "capexSource": 2000, "capexYear": 2022, "fomShare": 0.05, "stackShare": 0.11, "stackHours": 40000, "life": 30, "via": "e0.json farm.electrolyzer", "src": [ "doe-h2-24005", "eia-steo-9a" ] }, "indHP": { "cop": 3, "capex": 900, "life": 20, "set": "teaching", "note": "Set for teaching: industrial heat pumps for the food plants' heat below 100 C (washing, pasteurizing, hot water), COP 3.0, $900 per kW of heat, 20 years, running flat all year." }, "avoided": { "def": 35, "lo": 20, "hi": 80, "step": 5, "set": "teaching", "note": "Set for teaching: what one MWh from the wind contract or the solar farm saves the city's supplier when it replaces a bought MWh; the wires part of the bill is still paid." }, "gasInd": { "lo": 3, "hi": 7, "step": 0.25, "unit": "$ per thousand cubic feet", "set": "teaching", "note": "Set for teaching: the range C3's sensitivity test moves the industrial park's gas price over (prairie-city.json prices.gasPerMcf.industrial, itself set for teaching from EIA's Kansas citygate price); not a forecast." }, "note": "C3 plans Prairie City for 2040 with 2025's people, homes and prices and the course's synthetic weather: only the plan changes. The industrial park and the data-center campus take power at their own substations (no limit modelled); the park's new loads are flat all year." }, "sources": { "atb2025-fin": { "text": "NLR, 2025 Electricity Annual Technology Baseline, Financial Cases and Methods", "url": "https://atb.nlr.gov/electricity/2025/financial_cases_&_methods", "asOf": "checked 2 Nov 2026 (via 13-capstone.json)" }, "eia-aeo2026-rdm": { "text": "EIA, Assumptions to the Annual Energy Outlook 2026: Residential Demand Module, Table 2, p. 4 (heat pumps, furnaces; 2022 dollars) and Table 3, p. 5 (rooftop solar; 2022 dollars, 25-year life)", "url": "https://www.eia.gov/outlooks/aeo/assumptions/pdf/RDM_Assumptions.pdf", "asOf": "April 2026; checked 3 Nov 2026", "short": "EIA AEO2026, residential assumptions, Tables 2-3" }, "eia-aeo2026-emm": { "text": "EIA, Assumptions to the Annual Energy Outlook 2026: Electricity Market Module, Table 3, p. 5 (2025 dollars), and its note on storage losses", "url": "https://www.eia.gov/outlooks/aeo/assumptions/pdf/EMM_Assumptions.pdf", "asOf": "April 2026; checked 3 Nov 2026", "short": "EIA AEO2026, electricity assumptions, Table 3" }, "eia-steo-9a": { "text": "EIA, Short-Term Energy Outlook, Table 9a: GDP implicit price deflator (2017 = 100), yearly means 2022 118.035, 2023 122.389, 2024 125.430, 2025 128.989", "url": "https://www.eia.gov/outlooks/steo/", "asOf": "October 2026 issue (1 Oct 2026)", "short": "EIA STEO, Table 9a" }, "eia-dg-2024": { "text": "EIA, Distributed Generation, Battery Storage, and Combined Heat and Power System Characteristics and Costs in the Buildings and Industrial Sectors, Table 2-2, p. 12 (residential solar: 17.6% capacity factor in 2022)", "url": "https://www.eia.gov/analysis/studies/buildings/dg_storage_chp/pdf/dg_storage_chp.pdf", "asOf": "March 2024; checked 3 Nov 2026", "short": "EIA, distributed generation costs (2024), Table 2-2" }, "doe-h2-24005": { "text": "DOE Hydrogen Program Record 24005, Clean Hydrogen Production Cost Scenarios with PEM Electrolyzer Technology, Table 1, p. 2, and p. 9 (fixed and replacement costs)", "url": "https://www.hydrogen.energy.gov/docs/hydrogenprogramlibraries/pdfs/24005-clean-hydrogen-production-cost-pem-electrolyzer.pdf", "asOf": "20 May 2024; checked 3 Nov 2026", "short": "DOE Hydrogen Program Record 24005" }, "nrel-battery-2025": { "text": "Cole, Ramasamy and Turan, Cost Projections for Utility-Scale Battery Storage: 2025 Update, NREL/TP-6A40-93281 (2024 costs, section 2 and Figure 2; O&M and life, section 3)", "url": "https://docs.nlr.gov/docs/fy25osti/93281.pdf", "asOf": "June 2025" }, "bea-nipa-119": { "text": "U.S. Bureau of Economic Analysis, NIPA Table 1.1.9: Implicit Price Deflators for Gross Domestic Product, line 1, annual (2017 = 100): 2024 125.587, 2025 128.893", "url": "https://apps.bea.gov/iTable/?reqid=19&step=3&isuri=1&1921=survey&1903=13&1904=2022&1905=2026&1906=a&1911=0", "asOf": "last revised 29 October 2026; accessed 5 November 2026" }, "ornl-wap-2014": { "text": "Tonn and others, Weatherization Works: Summary of Findings from the Retrospective Evaluation of the U.S. Department of Energy's Weatherization Assistance Program, ORNL/TM-2014/338, Oak Ridge National Laboratory: executive summary p. xiv ($4,695 average cost a unit, program year 2008) and section 3.1, p. 12 (gas use of single-family gas-heated homes down 17.8%)", "url": "no link", "asOf": "September 2014; read 6 Nov 2026" } }, "precomputed": { "sb3": { "head": "Result: 2025 as it is, then \"Electrify heat and cars\" (80% of furnaces and resistance heat to heat pumps, half the cars electric)", "rows": [ [ "2025 as it is: yearly cost against 2025 (2025 dollars; equipment and upgrades as yearly payments)", "$0.0M" ], [ "2025 as it is: CO₂ of the three districts' buildings and cars", "1,921,977 t a year" ], [ "2025 as it is: busiest hour against the limit, core · suburbs · fringe", "213/250 · 192/230 · 48/60 MW" ], [ "2025 as it is: substation upgrades bought", "0 MW" ], [ "2025 as it is: energy burden, homes below 80% of area median income (screening estimate)", "6.1%" ], [ "Electrify heat and cars: yearly cost against 2025 (2025 dollars; equipment and upgrades as yearly payments)", "−$65.8M" ], [ "Electrify heat and cars: CO₂ of the three districts' buildings and cars", "1,527,234 t a year" ], [ "Electrify heat and cars: busiest hour against the limit, core · suburbs · fringe", "276/250 · 288/230 · 67/60 MW" ], [ "Electrify heat and cars: substation upgrades bought", "91 MW" ], [ "Electrify heat and cars: energy burden, homes below 80% of area median income (screening estimate)", "5.4%" ] ], "note": "Precomputed with HiGHS on 6 November 2026: the hub as a linear program over eight representative days. Prairie City is fictional; its numbers are illustrative. With JavaScript on, the bench runs your own plan." }, "m12": { "table": "
PlanYearly cost against 2025CO₂ of the districts (a year)Substation upgradesBurden, homes below 80% of area median income (AMI; screening)
2025 as it is$0.0M1,921,977 t0 MW6.1%
Electrify heat and cars−$65.8M1,527,234 t91 MW5.4%
Electrify, managed charging, 40 MW of batteries−$60.5M1,527,266 t48 MW5.5%
The LP's choice, CO₂ ≤ 80% of 2025−$86.2M1,537,582 t5 MW5.1%

Precomputed with HiGHS on 6 November 2026. Cost includes the cars' fuel and charging, not their prices; equipment and upgrades as yearly payments.

", "ref": { "runs": { "today": { "peaks": [ 212.807, 192.368, 48.012 ], "upg": [ 0, 0, 0 ], "cost": 614595991, "co2": 1921977, "imp": 2010138, "burdenLow": 0.06116, "burdenOther": 0.02036 }, "electrify": { "peaks": [ 275.525, 288.425, 67.496 ], "upg": [ 25.525, 58.425, 7.496 ], "cost": 548750600, "co2": 1527234, "imp": 2446087, "burdenLow": 0.05427, "burdenOther": 0.01818, "value": [ 40418.79, 40418.79, 40418.79 ] }, "flex": { "peaks": [ 256.855, 268.372, 62.922 ], "upg": [ 6.855, 38.372, 2.922 ], "cost": 554136706, "co2": 1527266, "imp": 2446165, "burdenLow": 0.05497, "burdenOther": 0.01841 }, "choose": { "peaks": [ 172.481, 168.698, 64.735 ], "upg": [ 0, 0, 4.735 ], "cost": 528394145, "co2": 1537582, "imp": 2050690, "burdenLow": 0.05093, "burdenOther": 0.01692, "capDual": 191.05, "hp": [ 0.307, 0.2677, 0.888 ], "pvAdd": 92.314 } }, "cap": 80, "base": 1921977, "my": { "plan": { "hp": 70, "ret": 40, "dh": 30, "dhp": 100, "sto": 800, "ev": 60, "evm": "managed", "pv": 100, "bat": 20 }, "burdenLow": 0.05216, "dhPrice": 130.8 } } }, "c3": { "head": "Result: 2025 as it is, then the reference plan of the exemplars (70% heat pumps, 40% electric cars, 200 MW of wind, a 100 MW solar farm at A19's site A)", "rows": [ [ "2025: up front, 2026 to 2040 (2025 dollars)", "$0.0M of a $1,500.0M budget" ], [ "2025: the city's yearly cost against 2025", "$0.0M" ], [ "2025: the city's CO₂ (location-based, operating)", "2,765,433 t a year" ], [ "2025: busiest hour against the limit, core · suburbs · fringe", "213/250 · 192/230 · 48/60 MW" ], [ "2025: energy burden, homes below 80% of area median income (screening)", "6.1%" ], [ "Reference plan: up front, 2026 to 2040 (2025 dollars)", "$1,227.9M of a $1,500.0M budget" ], [ "Reference plan: the city's yearly cost against 2025", "−$29.2M" ], [ "Reference plan: the city's CO₂ (location-based, operating)", "2,423,488 t a year" ], [ "Reference plan: busiest hour against the limit, core · suburbs · fringe", "250/250 · 256/230 · 60/60 MW" ], [ "Reference plan: energy burden, homes below 80% of area median income (screening)", "5.5%" ] ], "note": "Precomputed with HiGHS on 6 November 2026. Prairie City is fictional; its numbers are illustrative. With JavaScript on, you run your own plan." }, "c3ex": { "title": "Two summaries of the same brief", "task": "Recommend Prairie City's 2040 energy plan within the budget, and say who gains and who pays.", "id": "c3-ex", "lines": true, "answers": [ { "key": "weak", "label": "Weak summary", "level": "Developing", "parts": [ "Prairie City should ", { "text": "go green with heat pumps and wind", "note": "No sizes, no shares, no budget: the council cannot check or cost it." }, ". ", { "text": "Emissions will fall a lot", "note": "By how much, on what boundary, against which year?" }, " and ", { "text": "everyone will save money", "note": "Who? The household table is a screening estimate with an adoption rule; name the groups and the numbers." }, ". ", { "text": "Some people objected but the plan is the best", "note": "Each objection needs an answer: what you would change, or why you would not." }, "." ] }, { "key": "good", "label": "Strong summary", "level": "Proficient", "parts": [ "Recommendation: ", { "text": "switch 70% of furnaces and resistance heat to heat pumps, retrofit 10% of buildings, make 40% of cars electric with managed charging, add 30 MW of substation batteries, move the food plants' low-temperature heat to heat pumps, and contract 200 MW of wind and a 100 MW solar farm at site A", "note": "Every lever with its size: a plan the council can cost and check." }, ".\n", "Budget and cost: ", { "text": "$1,227.9M up front against $1,500.0M; the city's yearly cost −$29.2M against 2025 (energy bills plus equipment as yearly payments, 2025 dollars)", "note": "Up front and yearly kept apart, on one boundary." }, ".\n", "CO₂ and the grid: ", { "text": "the city's location-based CO₂ 2,423,488 t a year, 12% below 2025 (operating only; the contracts not deducted); 26 MW of substation upgrades, the suburbs the tightest", "note": "The cut with its boundary, and where the plan needs grid room." }, ".\n", "Who pays (screening): ", { "text": "energy burden of homes below 80% of area median income 6.1% → 5.5%, every group adopting alike; the cars' fuel and charging count as transport, outside the burden", "note": "The rule stated, and the estimate labelled as a screening estimate." }, ".\n", "Jobs (screening): ", { "text": "about 2,947 construction job-years to 2040 (gross), 2,358 net of displacement; at the farms 18 direct ongoing jobs, 29 gross supported, 23 net of displacement", "note": "Job-years kept apart from ongoing jobs, gross apart from net." }, ".\n", "Site: ", { "text": "site A, the best of A19's five blocks and the cheapest to connect ($5.3M), at a 23.8% capacity factor", "note": "The site's choice with its evidence from the map." }, ".\n", "Sensitivity: ", { "text": "the yearly cost runs from −$72.6M to −$2.9M with every input at its lower- or higher-cost end; value of a contract MWh moves it most, $20/MWh to $80/MWh; every tested input is set for teaching", "note": "A range, the input that matters most, and what kind of number each input is." }, ".\n", "Panel: ", { "text": "to the electric utility (26 MW of upgrades): I keep them, since with the plan's levers fixed they are the cheapest way to meet the suburbs' busiest hour (its dual equals the upgrade's yearly cost); to the climate group (12% cut): the wind and solar contracts do not lower the location-based CO₂ (a market-based report could claim about 301,316 t); deeper cuts need more heat pumps and retrofits, with $272.1M of the budget left; to the industrial park (+$2.2M a year, 7%): I keep the food plants' heat pumps for the gas they save, and show the park's gas price in the sensitivity table; to farmers and rural residents (site A): it is the screen's best block and the cheapest of the five to connect, $5.3M for its line, road and land, 1.0 km to S4, on about 542 acres", "note": "Each objection answered with a reason or a change, from the run's own numbers." }, ".\n", "Limits: ", { "text": "2025's people and prices held to 2040, one substation per district, eight representative days of synthetic weather, the household rule an assumption, the map's layers simulated", "note": "What the plan leaves out, so the council does not over-read it." }, "." ] } ], "note": "Both summaries are illustrative. The strong one quotes this engine's numbers for one reference plan within the budget, precomputed; another plan is just as strong when its evidence supports it." } } }