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ERCOT vs Oncor vs Centerpoint: supplier vs T&D fees

State spotlight

ERCOT runs the grid. Oncor and Centerpoint own the wires (TDU). REPs sell the energy. The fee bucket each one collects on a Texas bill.

Featured infographic

Three-layer Texas electricity market diagram

ERCOT (wholesale grid operator) → TDU (wires + delivery) → REP (supply rate). Each layer bills a different bucket.

Open graph image · /og/two-pool-bill.png

A Texas electric bill has three layers. ERCOT runs the wholesale grid. The TDU (Oncor, Centerpoint, AEP Texas, TNMP) owns the wires and bills delivery. The REP (Retail Electric Provider) sells the supply rate. Each layer collects a different fee bucket. Switching REPs changes only the supply portion. ERCOT and TDU charges are regulated and identical across all REPs in your territory.

The three layers and their roles

ERCOT (Electric Reliability Council of Texas) operates the wholesale grid. ERCOT does not deliver electricity to households or bill them directly. ERCOT runs the wholesale auctions, ensures grid reliability, and dispatches generators.

TDU (Transmission and Distribution Utility): Oncor (Dallas-Fort Worth), Centerpoint (Houston), AEP Texas (south + west), TNMP (north + central). TDUs own and operate the wires, transformers, and meters. TDUs deliver electricity, read meters, and handle outages.

REP (Retail Electric Provider): the company you contract with for your supply rate. The REP bills you for both their supply rate and the TDU delivery charges (passed through). Single bill from the REP covers everything.

Fee buckets on a Texas bill

TDU delivery: 3.8 to 4.4 cents per kWh + small fixed monthly charge. Regulated by PUCT. Identical across all REPs.

ERCOT system administration: typically 0.05 to 0.15 cents per kWh embedded in the TDU charge. The customer does not see ERCOT as a separate line.

REP supply: your contracted rate per kWh. Competitive. Locked rate if you have a fixed-rate plan; varies if you have variable or indexed.

Who do I actually pay?

You pay your REP. The REP collects both supply and delivery charges on your single bill, then remits the delivery portion to the TDU. You do not interact directly with the TDU for billing.

If you have a power outage, call the TDU emergency line, not your REP. The TDU restores service. Your REP only handles billing questions related to the supply portion.

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Common questions

Quick answers from the editorial desk

Who do I actually pay on a Texas electric bill?
Your REP. The REP collects everything on one bill including the TDU delivery charges (passed through). You do not pay the TDU directly under deregulated retail.
Can I switch my TDU?
No. The TDU is determined by your address. Dallas-Fort Worth is Oncor. Houston is Centerpoint. The TDU owns the wires; you cannot pick a different one for the same physical location.
Why does TDU charge a fixed monthly fee?
To cover the cost of the meter, the connection, and the wires regardless of how much electricity you use. Even a vacant home with zero kWh pays the fixed TDU charge for being connected to the grid.
Who do I report a power outage to — REP or TDU?
TDU. The TDU operates the wires and emergency response. Your REP only handles supply rate billing. Save the TDU emergency line in your phone separately from the REP customer service number.

Further reading

Pillar guide, cluster siblings, and state pages cited above

Sources

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