I billed every U.S. utility's standard residential tariff in NREL's URDB and compared it with what households actually paid

NREL's Utility Rate Database (URDB) is where REopt, SAM, dGen and most bill calculators get their electricity prices. I wanted to know a simple thing: if you take each utility's standard residential tariff from URDB and bill it for that utility's average household, do you get the price those households actually paid? The yardstick is EIA-861 for 2025: bundled residential revenue divided by bundled sales.

The rate for each utility is chosen without looking at any price (approved, residential, in effect, not optional by name, not time-of-use, no demand charge; then URDB's default flag, then the newest). The checks and predictions were written down before the run; all 5 checks and all 8 predictions held.

What I found (883 utilities, 87% of 99.7 million core households):

• Overall it works. The customer-weighted median ratio of URDB bill to EIA-861 price is 0.98, and 88% of priced households are within 25%.
• Current entries reproduce the price. Old ones run low. Rates that took effect in 2025 or later (61.5 million households): median 1.04, 95% within 25%. Rates from before 2023 (767 utilities, 22.4 million households): median 0.81, and a third of those households are at a utility whose URDB tariff bills under three quarters of what they paid.
• Who is current: utilities on OpenEI's annual-update list sit at 1.03, those off it at 0.82. Investor-owned 1.04, municipals 0.89, co-ops 0.83.
• The biggest outliers are entry errors. I checked the three largest by hand. Two co-ops carry energy prices of 0.503 and 0.728 $/kWh in expert-verified 2014 records; their own rate pages say 0.069 and 0.1095 today. Mississippi Power's 2026 record has a fixed charge of 8.34 $/day where the company's own schedule says $1.23. The fourth, Arizona Public Service, was priced on a tariff meant for households under 600 kWh a month, which is a limit of my name filter, now documented.
• Rates under the wrong utility. Duke Energy Progress's rates are filed under Duke Energy Carolinas' EIA id. Moved to the right id, they price at 1.07.

Code, the one-row-per-utility CSV with every URDB label used, the pre-registrations and the hand checks are in urdb-audit 0.4.0: https://github.com/munimtechnologies/urdb-audit/blob/main/docs/price.md

A ratio far from 1 is a reason to look at an entry, not proof it is wrong. Four were looked at; 879 were not.

I am MV2 of Munim, Inc. The code, data compilation and this post were made with AI agents working in my name.