HomeWattCost

Duke Energy Carolinas SC RS vs RSTC

RS and RSTC cost about the same for a typical South Carolina home (within $13 a year). RS is cheaper below about 1,900 kWh a month and RSTC above it, with the same daily pattern of use.

Utility Duke Energy CarolinasTariffs checked 2026-11-07Typical use 1,070 kWh/mo, South Carolina

Head to head

ScenarioRSRSTCCheaper
Typical home, per month$175$176Tie
All-in price per kWh16.3¢16.4¢RS
Home + EV, charged at the cheapest hour$217$204RSTC
Home + EV, plugged in at 6 pm$217$226RS
Fixed charge$12.07$13.20

Typical home: South Carolina average use by month (EIA), shaped hour by hour (NREL ResStock), before taxes. EV: Tesla Model Y Long Range AWD, 1,000 miles a month; cheapest start any hour on RS, 1 am on RSTC.

Month by month

Typical-home bill each month on each plan.

PlanJanFebMarAprMayJunJulAugSepOctNovDec
RS$208$184$136$128$150$194$242$232$166$137$136$182
RSTC$206$181$136$125$158$200$247$237$171$130$135$181

RS: price by hour

July weekday.

Same price all day
15.8¢12a3a6a9a12p3p6p9p12a

RSTC: price by hour

July weekday.

Off-peakMid-peakPeak
14.4¢10.1¢14.4¢27.8¢14.4¢12a3a6a9a12p3p6p9p12a

RS or RSTC: common questions

Is RS or RSTC cheaper?

RS and RSTC cost about the same for a typical South Carolina home (within $13 a year). RS is cheaper below about 1,900 kWh a month and RSTC above it, with the same daily pattern of use. Adding an EV driven 1,000 miles a month and charged at each plan’s cheapest hour, RSTC gives the lower total ($204 against $217 a month).

What is the difference between RS and RSTC?

RS is tiered: the price per kWh rises with monthly use, with a fixed charge of $12.07 a month. RSTC is time-of-use (summer weekdays: Mid-peak 12 am–1 am, Mid-peak 6 am–6 pm, Peak 6 pm–9 pm, Mid-peak 9 pm–12 am; lowest price 1 am–6 am), with a fixed charge of $13.20 a month.

More Duke Energy Carolinas comparisons

How the two plans work

RS: Residential Service

  • In July the first 1,000 kWh a month cost 15.1¢ each; then 15.8¢ above 1,000 kWh a month.
  • An average South Carolina home (1,499 kWh in July) goes past the first tier, so extra load such as an EV is priced higher.
  • Fixed charge: $12.07 a month.

RSTC: Residential Time of Use with Critical Peak Pricing

  • Mid-peak 12 am–1 am, Mid-peak 6 am–6 pm, Peak 6 pm–9 pm, Mid-peak 9 pm–12 am on July weekdays; 3 of 24 hours carry the top price of 27.8¢.
  • The cheapest July weekday hour costs 10.1¢, so moving 1 kWh out of the top hours saves 17.7¢.
  • January weekdays range from 10.1¢ to 27.8¢.
  • Summer pricing applies May–Sep; winter pricing Oct–Apr.
  • Weekends differ: Mid-peak 12 am–1 am, Mid-peak 6 am–12 am.
  • Fixed charge: $13.20 a month.

Your own pattern of use decides the winner: compare every Duke Energy Carolinas plan on your usage, or see all Duke Energy Carolinas plans, sources and peak hours.