ElectrifyCost

Sources

Sources

We anchor every cost driver, energy price, incentive amount, and building-load assumption to a primary source. 200 sources are catalogued below — federal agencies, national labs, code bodies, and independent research organizations. We re-review at least quarterly. The "last reviewed" badge on each calculator reflects the most recent review across the data that calculator uses.

Authority bias

We prefer .gov, national lab (.lbl.gov, .nrel.gov, .pnnl.gov), and major-association sources. Industry sites and contractor blogs are excluded.

Versioning

Every source has a last-reviewed date. We don't silently move numbers — model changes ship with notes.

Show-your-work

Each calculator's result page lists the specific source IDs used, with publisher and review date.

Federal tax credits

15 sources

Authoritative IRS and ENERGY STAR pages for the residential energy tax credits we apply (25C, 30C, 25D where relevant).

Rebate programs

29 sources

Federal, state, and program-administrator portals for rebates that stack with credits — DOE Home Energy Rebates, DSIRE, NYSERDA, Mass Save, TECH Clean California, and more.

Product eligibility lists

32 sources

ENERGY STAR Product Finder and NEEP databases used to verify equipment eligibility for credits and qualifying-equipment rebates.

Energy price data

14 sources

EIA retail-rate datasets for electricity, natural gas, propane, heating oil, and gasoline; updated quarterly.

Labor & equipment cost data

4 sources

BLS Occupational Employment & Wage Statistics for electricians, HVAC mechanics, and plumbers; PPI for equipment-price tracking.

Climate & weather data

1 source

NOAA climate normals (HDD/CDD) and ASHRAE/IECC climate-zone definitions used in our heating-load model.

Research & cost benchmarks

30 sources

NREL, LBNL, PNNL, RMI, ACEEE, and DOE Building Technologies Office studies that anchor our installed-cost ranges and operating-cost estimates.

Consumer guides

18 sources

Plain-language explainers from DOE Energy Saver, Building America, and Consumer Reports — what we point users to when they want to read more.

Codes & standards

16 sources

NEC (NFPA 70), ACCA Manual J/S/D, NEMA panel standards, ASHRAE design data, and IECC climate-zone definitions.

If you spot a stale link or value, the numeric tables (cost ranges, state multipliers, rebate programs, climate zones) live in data/csv/ and the source-notes index lives in src/data/source-notes.json. Every source row has a clear last_reviewed date.