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METHODOLOGY & DATA SOURCES

How SiteLitmus works

SiteLitmus turns a street address into a standardized, sourced first-look at whether a clean-energy project pencils — and what it takes to build it. The same diligence an experienced developer assembles by hand over a few hours, pulled from scattered tariff books, utility spec manuals, code tables and incentive rules, here arrives in minutes: consistent, cited, and confidence-scored.

Every number on a result card is traceable to a method and a public source, and is stamped with the date the underlying data was last verified. This page explains exactly how each module reaches its answer, what standards it follows, and — just as importantly — where it stops and a licensed professional or the utility takes over.

The modules & methods

⚡ Cost of power

Resolves the serving utility from the address, then computes a blended ¢/kWh from the applicable commercial tariff — energy, demand and fixed charges modeled against a usage profile.

Sources: a curated registry of ~185 U.S. utility commercial tariffs, backstopped by the U.S. Utility Rate Database (OpenEI USURDB). blended ¢/kWhdemand + energy

📈 Revenue & offtake

For generation/storage, values energy against the relevant regime: net energy metering (NEM 2.0 full-retail vs. NEM 3.0 / net-billing avoided-cost), an avoided-cost / PPA framing for exported energy, plus RECs and escalation. For EV charging, models session revenue from throughput and price assumptions you control.

Sources: published NEM / net-billing schedules and avoided-cost (ACC) values, LBNL and wholesale LMP references for export pricing. NEM 2.0 / 3.0PPA / avoided-costRECs

🔌 Grid hosting capacity (export headroom)

Reads the serving utility's published Integration Capacity Analysis (ICA) layer at the project's location to estimate how much generation the local circuit can absorb before upgrades are likely triggered.

Sources: utility ICA / hosting-capacity map services (live for PG&E and SCE today, expanding to additional open data utilities). utility ICAcircuit-level

🔀 Interconnection & metering

Surfaces the service and metering design facts you can determine without contacting the utility — metering sequence (hot/cold), CT-location options, dedicated termination, EUSERC, and the primary-(MV)-vs-secondary-(LV) metering threshold for your service size. Project-specific items that genuinely require utility contact are grouped separately rather than guessed.

Sources: a utility metering matrix covering 99+ utilities plus deep profiles built from real Electric Service Requirements Manuals (ESRM / "blue books"). ESRM-basedMV vs LV

📜 Permitting

Maps the project to its Authority Having Jurisdiction (AHJ) and returns the permitting framework — adopted code cycle, licensing, plan-review and inspection path, ADA, and (for storage) fire-code requirements. Curated AHJs return validated detail; others return the authoritative state framework with site-specific fields flagged to verify.

Sources: state code frameworks + a curated AHJ database (top ~200 metros by population), referencing NEC, NFPA 855 / IFC (ESS), and ADA. NECNFPA 855 / IFCADA

🎁 Incentives

Estimates the federal investment tax credit (§48E) on the eligible basis and layers eligible adders — energy community, domestic content, low-income, and prevailing-wage / apprenticeship — alongside applicable state and utility programs.

Sources: current federal statute and IRS guidance plus a curated state/utility program set; reflects post-2025 legislation. §48E ITCenergy-community / DC / LMI adders

📐 Engineering single-line diagram

Generates a preliminary, engineering-grade one-line: load/PV/storage sizing, overcurrent protection, conductors, transformer, and a screening available-fault-current value, drawn with standard IEEE-315 / ANSI symbols and a title block. Intended as a draft a licensed Professional Engineer can finalize and stamp.

Standards: NEC 310.16, 625, 690 & 705 sizing; IEEE 315 / ANSI Y32.2 symbols; infinite-primary fault-current screening. NEC 690/705IEEE 315PE-stampable draft

Confidence scoring & data freshness

Confidence (1–5)

Each result carries a 1–5 confidence score with a plain-language reason. Higher scores mean the answer came from deep, validated data (a real spec book or curated AHJ); lower scores mean a standard framework was applied and specific fields should be verified. Nothing is presented as more certain than the data supports.

"As of" dating

Data-driven cards show the date the underlying source was last verified. A re-verification cadence runs in the background (codes annually; tariffs, fees and programs more often), and any value past its cadence is flagged ⚠ verify rather than shown as current — so you always know how fresh a number is.

What this is — and isn't

Screening-grade, not a commitment. SiteLitmus accelerates early due diligence; it does not replace a utility study, a stamped engineering design, or counsel. Interconnection results are not a utility commitment of capacity. The single-line is a preliminary draft requiring review and stamp by a licensed Professional Engineer before submittal. Permitting and incentive outputs are informational and not legal, tax, or financial advice. Always confirm site-specific items with the utility, the AHJ, and your advisors.

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Go deeper: The five-question feasibility framework for clean-energy sites — our cross-segment whitepaper on screening any site fast.

SiteLitmus aggregates and standardizes publicly available data (utility tariff and spec publications, ICA map services, OpenEI USURDB, federal and state code and incentive sources). Figures are estimates for screening purposes. © SiteLitmus.