Duke Energy offers a voluntary time-of-use program in North Carolina called the Flex Savings Option. Enrolling requires a smart meter. The peak hours shift by season:
- Summer (May 1 – September 30): Peak 6–9 pm. Discount hours 1–6 am.
- Winter (October 1 – April 30): Peak 6–9 am. Discount hours 1–3 am and 11 am–4 pm.
Off-peak covers everything else. Rates differ by territory:
| Period | Duke Energy Carolinas (Charlotte) | Duke Energy Progress (Raleigh) |
|---|---|---|
| Discount | 7.05¢/kWh | 6.88¢/kWh |
| Off-peak | 9.74¢/kWh | 9.50¢/kWh |
| On-peak | 21.34¢/kWh | 20.80¢/kWh |
| Critical peak | 44.26¢/kWh | 43.18¢/kWh |
On up to 20 designated critical peak days per year, the on-peak rate jumps to the critical peak figure above. Duke notifies customers a day in advance by text or email.
Rates verified April 2026. Verify current figures at duke-energy.com before quoting to customers.
This affects battery storage differently by season. In summer, a battery can store solar generation during the day and discharge it during the evening peak window. In winter, the peak is in the morning, so the more useful strategy is charging the battery overnight during discount hours and drawing from it during the 6-9 am peak.
Duke Energy’s Power Manager Battery Control program takes this further. Duke manages when your battery charges and discharges in exchange for a monthly bill credit, specifically targeting those peak and discount windows. It’s available as an add-on to the PowerPair incentive program.
When you’re getting quotes
The Flex Savings Option is voluntary. Electricity is cheaper 21 hours a day under it — only the three on-peak hours cost more than the standard flat rate. For homeowners who can shift big loads (EV charging, water heater, dishwasher) out of those three hours, the math tends to work in their favor. Customers who actively shift loads report saving $10–35/month.
If you’re adding a battery, ask your installer whether enrolling in the Flex Savings Option would change the financial case. The battery can charge during discount hours and discharge during the 6–9 pm or 6–9 am peak window, capturing the full rate spread automatically.
Common questions
- What are Duke Energy's peak hours in North Carolina?
- Under Duke Energy's Flex Savings Option, peak hours are 6–9 pm in summer (May–September) and 6–9 am in winter (October–April). Current summer rates for all-electric homes: Duke Energy Carolinas (Charlotte) — on-peak 21.34¢, off-peak 9.74¢, discount 7.05¢, critical peak 44.26¢/kWh. Duke Energy Progress (Raleigh) — on-peak 20.80¢, off-peak 9.50¢, discount 6.88¢, critical peak 43.18¢/kWh. Both utilities can call up to 20 critical peak days per year with a day's advance notice.
- Should I enroll in Duke Energy's Flex Savings Option if I have an EV charger?
- For most EV owners, yes. Electricity is cheaper 21 hours a day under the Flex Savings Option — only the three on-peak hours cost more than the standard flat rate. Customers who shift loads (EV charging overnight, water heater off during peak) report saving $10–35/month. An EV charged during discount hours (1–6 am in summer) is about as cheap as residential electricity gets. Smart chargers with scheduling features handle this automatically.
- How do time-of-use rates affect solar savings in North Carolina?
- They can reduce solar savings if your system exports power during off-peak hours when credits are worth less. Most NC homes export solar production in the middle of the day, which is off-peak under the Flex Savings Option. Adding a battery lets you store that midday production and use it during the 6–9 pm peak window rather than exporting it at a low credit rate.