How Oncor separates small and demand-billed business accounts

Oncor publishes its retail delivery service tariff and rate schedules and an easy-to-read Delivery Charges 101 page. Oncor explains that charges depend on the PUCT-approved rate schedule, and that common business schedules include Secondary Service less than or equal to 10 kW and Secondary Service greater than 10 kW.

How Oncor generally calculates demand

For small secondary service, several delivery items are usage-based and billed per kWh. For Secondary Service greater than 10 kW, the bill can include demand-based components such as Distribution System Charge by Billing kW, certain rider items by Billing kW, and transmission-related components by NCP kW or 4CP kW depending on the tariff item.

Oncor states that kW demand is recorded as the highest demand over a 15-minute period during the billing month. It also explains that, in many cases, Billing kW is the higher of current NCP kW or 80% of the highest monthly NCP kW established in the prior 11 months. That ratchet is why one high-demand event can affect multiple future bills.

Practical takeaway: an Oncor business with rooftop HVAC, kitchen equipment, compressors, or refrigeration should avoid starting large loads together. Lowering the energy supply price helps, but preventing a large 15-minute spike may also lower the total bill.

How CenterPoint separates small and demand-billed business accounts

CenterPoint Energy Houston Electric posts its current tariff for retail delivery service, which contains delivery charges payable by the competitive retailer. In the CenterPoint tariff, non-residential secondary service is generally separated between less than or equal to 10 kVA and greater than 10 kVA.

How CenterPoint generally calculates demand

For Secondary Service less than or equal to 10 kVA, CenterPoint uses the small non-residential schedule when the customer’s peak demand is 10 kVA or less and has not exceeded that threshold in the previous 11 months. If the monthly peak goes over 10 kVA, the account can be moved to Secondary Service greater than 10 kVA for at least 12 months under the tariff.

For demand-billed CenterPoint accounts, NCP kVA is generally the kVA supplied during the 15-minute period of maximum use in the billing month. For Secondary Service greater than 10 kVA, the Distribution System Charge billing kVA is the current month’s NCP kVA. For Primary Service, CenterPoint’s tariff can use the higher of current NCP kVA or an 80% ratchet for certain larger loads. Transmission-voltage or IDR-metered charges may use 4CP kVA where applicable.

Practical takeaway: CenterPoint business customers should monitor both kWh and the highest 15-minute kVA interval. A short equipment spike can move the account into a demand-billed class or increase the delivery portion of the bill.

How AEP Texas Central separates business rate classes

AEP Texas publishes electric rate schedules for transmission and distribution service. For AEP Texas Central customers, the important business dividing line is often Secondary Voltage Service less than or equal to 10 kW versus Secondary Voltage Service greater than 10 kW, with additional classes for primary and transmission service.

How AEP Texas Central generally calculates demand

For Secondary Voltage Service greater than 10 kW, AEP’s tariff identifies service for non-residential delivery at secondary voltage with demand above 10 kW through one meter. The monthly delivery calculation can include customer and metering charges, distribution system demand billing, transmission-related demand billing, and applicable riders.

AEP’s tariff explains that 4CP billing demand for transmission system charges is based on the customer’s integrated 15-minute demands at the time of ERCOT’s monthly system 15-minute peak demand for June, July, August, and September of the prior year. For distribution system charges, the NCP kW billing demand is the kW supplied during the 15-minute period of maximum use, and the billing demand can be the higher of current NCP or an 80% ratchet depending on the schedule.

Practical takeaway: AEP Texas Central customers should review interval data in the summer and avoid controllable peaks during hot afternoon conditions, especially if the account is large enough to have 4CP exposure.

How AEP Texas North uses the AEP Texas tariff structure

AEP Texas North customers are also served under AEP Texas delivery tariff structures and rate schedules. Even when the customer changes retail electric providers, the AEP delivery tariff tied to the ESI ID controls the delivery pass-through charges.

How AEP Texas North generally calculates demand

The process is generally the same concept as AEP Texas Central: determine the correct service class, measure the account’s demand, apply the tariff’s customer, metering, kWh, demand, transmission, and rider components, and pass those charges through on the retail bill.

For demand-billed accounts, the customer’s 15-minute peak can drive NCP demand. Larger accounts may also need to understand 4CP because ERCOT’s summer peak intervals can affect transmission-related charges under the applicable tariff rules.

Practical takeaway: in AEP Texas North, a lower supply rate is only one part of the savings plan. Load scheduling, HVAC staging, and reviewing demand history can be just as important as shopping for the lowest business electricity rate.

How TNMP separates business rate classes

Texas-New Mexico Power publishes its retail delivery service tariff for the TNMP service territory. TNMP uses a smaller-business breakpoint of Secondary Service less than or equal to 5 kW, with larger Secondary Service greater than 5 kW and separate primary and transmission classes.

How TNMP generally calculates demand

For TNMP’s larger secondary service, tariff items can distinguish Non-IDR metered charges by NCP kW and IDR-metered charges by 4CP kW. TNMP’s tariff also states that billing kW for the Distribution System Charge is generally the higher of the current month’s NCP kW or 80% of the highest monthly NCP kW in the prior 11 months, with exceptions for certain seasonal, low-load-factor, or lower-demand accounts.

Practical takeaway: TNMP customers should know whether the account is IDR-metered or non-IDR-metered. That can change whether a demand component is tied to monthly NCP demand or 4CP-style billing determinants.

How LP&L separates business rate classes

Lubbock Power & Light provides LP&L document resources and its FY 2025-2026 System Delivery Tariff. LP&L’s tariff separates Secondary Service less than or equal to 10 kW from Secondary Service greater than 10 kW, plus primary distribution, primary substation, and transmission-voltage delivery classes.

How LP&L generally calculates demand

For Secondary Service less than or equal to 10 kW, LP&L states that it evaluates demand once per year in October, and if the customer’s demand exceeds 10 kW during that year, the premise is assigned to Secondary Service greater than 10 kW until the next evaluation. For service above 10 kW, LP&L includes a delivery system demand charge per kW under the tariff.

LP&L also states that it furnishes metering equipment to measure the customer’s kW demand of greatest use during the month for applicable demand-billed classes. Primary and transmission classes can also include power-factor and loss-adjustment provisions, so larger facilities should review the tariff and their interval data closely.

Practical takeaway: in LP&L territory, a business that crosses the 10 kW threshold can see a different delivery billing structure. Avoiding preventable peak demand can matter as much as comparing the retail supply rate.