Methodology

Alex Reyes — Founding editor

Alex trained as an electrical engineer and has spent the fourteen years since working in the energy sector — the years that taught the difference between a rate schedule that looks simple on paper and the tiered, time-of-use bill it actually produces.

WattClear exists because that gap is exactly what most bill-comparison tools paper over. It is built to price a household's actual tariff correctly rather than quote a state average, and to say plainly when a figure cannot be trusted rather than publish a confident guess.

Rate structures come from the NREL/OpenEI Utility Rate Database, published by NREL and OpenEI under CC0 1.0. The current snapshot holds 450 residential tariffs from 45 utilities, retrieved September 2, 2026. 450 of them can be priced for a household.

A pilot snapshot, not national coverage. Utilities are discovered by probing population-centre coordinates in 18 states, because URDB cannot be queried by utility or by address. A provider outside every probed territory — most rural cooperatives — will not appear here yet.

Geographic attribution is separate: US Census Bureau Geocoder (public domain), geographies at the coordinate the tariff was discovered at. Only tariffs discovered through an archived, coordinate-anchored URDB query can be attributed. Curated edge-case records and any anchor whose fetch never completed have no coordinate and therefore no state; they appear on utility pages only.

Every figure is produced by the same rate engine, whether it appears in a calculator or on a utility page. It reads the published tariff structure and applies it to a consumption profile — it does not use an average rate, and it does not interpolate between published figures.

The engine models:

• Tiered energy charges, including per-tier adjustments. Tier bands reset each billing month, so seasonal usage matters: the same annual total spread unevenly costs more.
• Time-of-use periods, from the 12×24 weekday and weekend schedule matrices URDB publishes, including seasonal period changes.
• Demand charges, both scheduled and flat monthly.
• Fixed and minimum charges, billed whether or not any electricity is used.

Calendar effects are real and are modelled: bills are computed against the 2026 calendar, so month lengths and the weekday/weekend split are the actual ones, not an average.

Where a value is not supplied, an assumption is made — and every assumption travels with the number it affects. Open “How this was worked out” on any result to see the list, including whether each assumption is likely to push the estimate up or down.

The significant ones:

• Hourly usage shape. Given only a monthly total, consumption is spread evenly across every hour. On a time-of-use tariff that is a real limitation — a household concentrating usage in peak hours pays more than this shows, one avoiding peaks pays less. Those estimates are marked low confidence for exactly this reason, and no load-shape dataset has been adopted to fill the gap because none has been approved as a source.
• Taxes. Zero unless entered. Most US jurisdictions add sales or utility tax, so an untaxed figure understates a real bill.
• Riders. Fuel and environmental adjustments are included where URDB publishes them as part of the rate structure. Riders billed outside the schedule are not captured.

Effective rate

The total bill divided by the kilowatt-hours used. It is the only figure comparable across plans, because it includes fixed charges. Advertised headline rates exclude them and therefore always look lower.

Tiered tariff

Charges more per kilowatt-hour as monthly consumption climbs through bands. The practical consequence: an added appliance is billed at whatever band the rest of the household has already reached, not at the household average — which is why multiplying watts by an average rate understates its cost.

Time-of-use tariff

Prices the same kilowatt-hour differently depending on the hour and the season. Shifting flexible loads changes the bill without changing total consumption.

Demand charge

Billed on the highest rate of draw in a period, not on total consumption. Rare on residential plans, and costly when present.

Fixed charge

A standing monthly amount billed regardless of usage. On a low-usage household it can exceed the cost of the electricity itself.

Export-only schedule

A net-metering rate that publishes a sell-back price and no purchase price. It cannot price household consumption, so the engine refuses it rather than treating the missing rate as zero and reporting free electricity.

Pages generated from data are not published automatically. Each is measured before it is allowed into the index, and one that falls short is still readable but carries noindex and states why on the page.

The thresholds:

• at least 10 computed facts specific to that entity
• at least 250 words of narrative generated from its own data
• at least 1 table or chart built from that data
• a data-quality score of 0.7 or better, combining how many plans are priceable, how complete the records are, and how recently they were fetched
• no more than 82% textual similarity to any other published page

Where several pages would describe an identical set of tariffs, one is chosen as canonical and the others point at it. Three addresses for one page helps nobody.

Estimate based on published tariff data. Your actual bill may differ. WattClear is not a utility, broker, or financial advisor.

Estimates are priced at 500, 1,000, 2,000 kWh per month on entity pages, and at whatever you enter in the calculators. They describe published tariffs, not your account: deposits, arrears, budget-billing arrangements and the fact that meter reads rarely align with calendar months all sit outside them.

If a number here looks wrong, the source link on the page goes to the tariff record it came from. Checking it against a real bill is the right instinct, and the gap between the two is itself informative.