WattPal Architecture & Methodology
Under the Hood: How WattPal Analyzes Texas Electricity Plans
Most electricity shopping sites look at three arbitrary snapshot numbers (500, 1,000, and 2,000 kWh) or rely on provider referral commissions. Here is how WattPal's engine actually analyzes your interval data against live Texas plans.
Published Sep 28, 2026 · By WattPal Editorial Team
35,040
15-min intervals analyzed per home
750+
Active Texas EFLs parsed & monitored
10M+
Calculations evaluated per report
$0
Broker kickbacks, ads, or bias
1. 15-Minute Interval Ingestion (35,040 Data Points)
Every home with a smart meter in the deregulated ERCOT grid records energy usage in 15-minute intervals. A standard 12-month export from Smart Meter Texas contains exactly 35,040 individual readings (4 intervals/hour × 24 hours × 365 days). Evaluating those 35,040 intervals across ~300 applicable active plans in your utility territory yields over 10.5 million calculation operations per report—before factoring in monthly tiered brackets, bill credits, and base charges.
Why interval granularity matters:
Seasonal Swings
Texas summers require massive air conditioning loads, while mild spring and autumn months drop usage substantially. Annual average calculations hide seasonal bill jumps.
Peak vs. Off-Peak Timing
When you run appliances, cook, or charge an electric vehicle directly determines whether a time-of-use (TOU) plan saves you money or penalizes you.
Learn how to export your interval file in our Smart Meter Texas CSV Guide.
2. Daily Extraction of 750+ Electricity Facts Labels
Electricity providers publish legally binding rate terms on an Electricity Facts Label (EFL). WattPal continuously tracks and parses over 750 active EFL documents across all deregulated Texas utilities (Oncor, CenterPoint Energy, AEP Texas Central, AEP Texas North, and Texas-New Mexico Power [TNMP]), extracting:
Retail Energy Charge
The fixed or tiered rate per kWh charged by the Retail Electric Provider (REP).
Base / Monthly Customer Charge
Fixed monthly account fees (often $4.95 to $9.95/month) applied regardless of usage.
TDU Delivery Charges
Regulated utility pass-through delivery fees updated bi-annually with PUCT tariffs.
Bill-Credit Triggers & Caps
Exact usage minimums and maximums required to trigger bill credit discounts.
You can test individual EFL documents using our free EFL Inspector Tool.
3. Bill-Credit Cliff & Fine-Print Detection
Many of the "cheapest" plans on comparison websites use bill-credit cliffs. For example, a plan might offer a $100 credit if you use between 1,000 and 2,000 kWh in a billing cycle. If you use 995 kWh in April or 2,005 kWh in August, you receive $0 credit and your effective rate doubles.
How WattPal evaluates credit traps:
Instead of checking if your annual average hits 1,000 kWh, WattPal runs the calculation for each individual monthly billing period using your actual recorded readings. If you miss the credit in shoulder months, WattPal's total annual cost accurately reflects that penalty.
For a deep dive on credit mechanics, read our Bill-Credit Trap Guide.
4. Real Time-of-Use (TOU) & Solar Buyback Matching
Time-of-use plans (e.g., Free Nights from 9 PM to 6 AM, or Free Weekends) charge higher daytime rates in exchange for free off-peak electricity. Generic comparison tools cannot accurately score these plans because they do not know when you use electricity.
Our hourly simulation methodology:
- • Window binning: Each 15-minute interval is tagged as paid or free based on the plan's exact day-of-week and hourly window.
- • TDU delivery pass-through: Even when energy is free, some plans pass through TDU delivery fees during free hours. WattPal models both fully exempt and energy-only free structures.
- • Solar export evaluation: For rooftop solar homes, export credits are calculated using contracted buyback rates exclusively during paid windows, ensuring zero-credit periods during free windows don't artificially inflate projected earnings.
To see how break-even analysis works for TOU schedules, read our Free-Nights Analysis Guide.
Independent & Math-Only: Why $9.99?
“If you aren’t paying for the product, you are the product.”
“Free” electricity comparison sites and brokers make money through referral commissions (often $100 to $150 per enrolled customer). That business model inherently incentivizes brokers to steer you toward high-commission providers and sponsored plans.
WattPal charges a simple, one-time $9.99 fee for a comprehensive 12-month analysis report. We do not accept broker fees, affiliate payments, or sponsored rankings from energy companies.
Editorial Methodology & Data Sources
WattPal rate data is sourced directly from public Electricity Facts Labels (EFL) filed under the Public Utility Commission of Texas (PUCT) §25.475 disclosure rules and retail offers indexed from Power to Choose. Regulated delivery tariffs are derived from certified transmission and distribution utilities (Oncor, CenterPoint Energy, AEP Texas Central, AEP Texas North, and Texas-New Mexico Power [TNMP]). Calculations use exact decimal arithmetic and evaluate individual calendar billing periods rather than annual averages.
Ready to analyze your electricity data?
Upload your Smart Meter Texas CSV to see your ranked plans across every active Texas provider.
See real-world data in our 15-minute usage case study, read our EFL guide, test rate structures in the plan simulator, or visit the Guides hub.