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Tariff data · 2026-08-27

Southwestern Public Service Co · TX

When are Southwestern Public Service’s peak hours?

Southwestern Public Service’s peak hours are noon–6pm, midnight–midnight, June–September. Everything outside those hours is off-peak.

At peak, Residential Heating Service TOU - Rate 39 charges 28.5¢ a kWh; off-peak it is 8.3¢ 3.4× apart. Prices from the filed tariff.

These hours only apply if you are on a time-of-use plan. Southwestern Public Service’s default plan, R (Residential Service) - Rate 1, charges one rate at every hour of the day. A household that never switched has no peak hours to avoid — and no cheap hours to use.

What the day looks like on Residential Heating Service TOU - Rate 39

  • peak28.55¢
  • off-peak8.29¢
Weekdays
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Weekends
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Full pricing, eligibility and the annual cost for three households: Residential Heating Service TOU - Rate 39

Every Southwestern Public Service plan with peak hours

Peak hours and prices on each Southwestern Public Service time-of-use plan
PlanPeak hoursPeakOff-peakWeekends
Residential Heating Service TOU - Rate 39noon–6pm, midnight–midnight, June–September28.5¢8.3¢partly priced

Peak and off-peak are the highest and lowest energy prices on each plan; some plans add a shoulder price between them. Fixed monthly charges are not included here — they are on each plan’s page.

What is it worth to move a load out of peak?

On Residential Heating Service TOU - Rate 39, every kilowatt-hour a day you move from noon to midnight is worth about $74 a year in the month the gap is widest. An electric car charging 10 kWh a night, or a water heater on a timer, is the kind of load that actually moves.

When should you charge an electric car at home? →

Where this comes from

Hours and prices are read from the tariff Southwestern Public Service filed with its regulator, as published in the NREL Utility Rate Database, and drawn the same way on every plan page. If your plan is not listed here, either it has no hourly pricing or its filing is too old or too partial for us to price honestly — we leave those out rather than guess.

All Southwestern Public Service plans compared →