Base Charge
A flat monthly fee charged regardless of usage. Also called "monthly customer charge" or "minimum usage fee". Typically $4.95 to $9.95 per month for residential Texas electricity plans.
Example
For low-usage households (under 600 kWh/month), a $9.95 base charge adds ~1.7¢/kWh to the effective rate all on its own — often more than the difference between plans.
Bill Credit
A flat dollar discount applied to your monthly bill ONLY when usage hits a specific kWh threshold (typically 1,000 or 2,000 kWh). Miss by a single kWh and the credit vanishes entirely — the most common trap in Texas electricity.
Example
A plan advertising 9.7¢/kWh with a $100 bill credit at 1,000 kWh has an effective rate of 9.7¢ only if you hit 1,000+ kWh. At 950 kWh the effective rate jumps to 14.2¢ — a 46% increase.
Deregulated Market
An electricity market where consumers can choose their retail provider. About 85% of Texas ZIP codes are deregulated. In non-deregulated areas (like most of Austin and San Antonio proper), you have no choice — the local municipal utility is your only option.
Example
Austin Energy and CPS Energy (San Antonio) are municipal utilities, not deregulated REPs. Residents inside their service territories cannot shop for electricity plans; residents in surrounding suburbs often can.
Effective Rate
Your actual cost per kilowatt-hour including every fee, charge, credit, and tax. Calculated as total bill divided by total kWh. The only rate that matters for comparing plans honestly.
Example
A plan advertised at 10.9¢/kWh can have an effective rate of 16¢/kWh if you fall below a bill-credit threshold. Voltcheckr computes effective rate automatically from your uploaded bill.
EFL (Electricity Facts Label)
A legally-required one-page disclosure for every Texas retail electricity plan. Shows the rate, fees, term, early termination fee, and the average price per kWh at 500, 1,000, and 2,000 kWh usage levels.
Example
Before signing any Texas electricity contract, always read the EFL — the number in the usage column closest to YOUR average kWh is the only number that matters.
ERCOT (Electric Reliability Council of Texas)
The independent operator that manages the electric grid serving about 90% of Texas. ERCOT handles real-time generation dispatch, grid stability, and the switching process when you change providers.
Example
When you switch electricity providers in Texas, the new REP submits a Move-In request through ERCOT's switching system and ERCOT handles the cancellation of your old service automatically.
ESI-ID (Electric Service Identifier)
A 17-digit number that uniquely identifies your electric meter in the ERCOT system. Required when signing up with a new Texas electricity provider. Printed on every Texas electricity bill.
Example
If you can't find your ESI-ID on your bill, most Texas REPs can look it up from your service address. The ESI-ID never changes, even if you switch providers 10 times.
ETF (Early Termination Fee)
A penalty charged when you cancel a fixed-term Texas electricity contract before it expires. Typically $150 to $295 depending on the provider and contract length.
Example
Texas law grants a 14-day grace period before your contract end date during which you can switch without paying the ETF. Voltcheckr auto-calculates whether switching mid-contract still saves money net of the ETF.
Fixed-Rate Plan
A Texas electricity plan where the energy rate is locked for the duration of the contract (typically 12, 24, or 36 months). Protects against rate spikes but locks out any savings if wholesale rates drop.
Example
The safest fixed-rate term for most Texas households is 12 months — long enough to lock in predictability, short enough to re-shop when rates shift. 36-month locks are rarely worth the ETF risk.
Free Nights Plan
A Texas electricity plan that charges 0¢/kWh during a specified nighttime window (typically 9pm-6am) and a premium rate during paid hours. Only saves money if you shift significant usage to the free window — EV owners, pool pumps, or battery storage households.
Example
You need roughly 37% of your monthly usage to happen in the free window for a free-nights plan to break even against a standard 12¢/kWh fixed plan. Typical households get 15-25% overnight usage.
kWh (Kilowatt-hour)
The unit of electrical energy you're billed for. One kWh is the energy a 1,000-watt appliance uses running for one hour. Your monthly usage is measured in kWh.
Example
A typical Texas household uses between 800 and 2,500 kWh per month, depending on house size, AC load, and season. Summer usage in Houston can be double the winter baseline.
Power to Choose
The state-run Texas electricity plan comparison website operated by the Public Utility Commission (PUC). Lists every retail plan available in every deregulated ZIP code, though its sort order favors bill-credit plans that game the display.
Example
Voltcheckr pulls fresh data from Power to Choose every night but ranks plans by effective rate at YOUR usage instead of advertised rate at 1,000 kWh.
PUC (Public Utility Commission of Texas)
The state agency that regulates Texas electricity, telecom, and water utilities. Enforces the Electricity Facts Label requirement, handles consumer complaints, and operates the Power to Choose website.
Example
If you have a dispute with your Texas electricity provider that customer service can't resolve, filing a formal complaint with the PUC is free and typically gets a response within 30 days.
REP (Retail Electric Provider)
The company you pay for electricity. In deregulated Texas markets, you choose your REP (TXU, Reliant, Gexa, etc.) but the electricity itself flows through the same TDU wires regardless.
Example
Switching REPs does not involve any physical change to your service, meter, or wires. Only the company you pay changes.
TDU (Transmission and Distribution Utility)
The company that owns the poles, wires, and meters delivering electricity to your home. In Texas, the TDU is separate from your retail provider and cannot be chosen — it's determined by your address.
Example
Houston is served by CenterPoint Energy as its TDU. Dallas and Fort Worth are served by Oncor. You can shop retail electricity providers but your TDU stays the same.
Variable-Rate Plan
A month-to-month Texas electricity plan where the rate can change with wholesale market conditions. No ETF and no long-term commitment, but significantly more risk during summer price spikes.
Example
Variable-rate plans are a good fallback for customers between contracts (e.g., moving in 2 months) but a terrible default choice because Texas summer wholesale rates can 3x in a single month.