Methodology

How Megawatt Index builds, checks, dates and refreshes its datasets and calculators.

Four kinds of page

• Trackers follow things that change status: bills, utility tariffs, local moratoriums.
• Datasets republish an official table in a form you can sort, filter and download, such as EIA electricity prices or BLS wages.
• Directories list records or organizations from official sources, such as state facility records or operators' careers pages.
• Calculators do arithmetic on your inputs with published constants, and show every assumption.

Sourcing rules

• Each row comes from an official or public source: a federal or state agency, a utility commission docket, a legislature, a county or city record, a utility tariff, or an operator's own report.
• Each row stores the URL it was checked against (source_url) and the date of that check (verified_at). Both are in every CSV download.
• A page's last updated date is the newest check date among its rows.
• Numbers are recorded exactly as the source states them, with the source's unit and reporting period. Where we convert units (for example liters to gallons), the converted column is labelled.
• We do not copy other trackers' datasets, and we do not take figures from search engine summaries.

Estimates

Only calculators estimate, and only for a hypothetical site you describe. They show a low, middle and high result where the published inputs are a range, label the result as an estimate, and list each constant with its source. We never estimate the electricity or water use of a named facility.

How often data is refreshed

• Bills and large-load tariffs: an automated job rechecks each row's official source page every week and updates status fields when the page changes. A row's check date moves forward only when its source was fetched and read successfully; sites that block automated checks are listed in the job's report and rechecked by hand.
• Electricity rates: refreshed when EIA publishes a new Electric Power Monthly, usually late each month.
• Pay data: refreshed when BLS publishes new Occupational Employment and Wage Statistics, once a year in spring.
• Everything else: rechecked by hand at least once a quarter, and whenever a reader reports a change.

State pages

A state page is published only when we hold enough verified rows about that state across our datasets to be useful on its own. States below that bar link to the national datasets instead.

Mistakes

If you find one, see corrections. Every change made because of a report is logged there.