South Carolina Utility Guide

Solar Choice & Time-of-Use Rates

Updated over 2 weeks ago

Top Takeaways

1. Time-of-Use rates are required with solar
2. Dominion has 1-to-1 Net Metering with a November settlement
3. Duke Energy has Monthly Net Metering (monthly settlement), and a $30 minimum bill

Net Metering in South Carolina

South Carolina closed its traditional net metering program to new customers in June 2021. Today's program is called 'Residential Solar Choice.' Solar customers are required to change rate plans to a Time-of-Use (TOU) rate.

TOU rates charge more for consumption during on-peak hours, and less during off-peak hours compared to the standard rate. In South Carolina, excess production is only allowed to net with grid consumption in the same TOU period it's produced in. Excess on-peak credits may net with on-peak grid consumption, and off-peak credits may net with off-peak consumption.

Dominion Energy and Duke Energy (DEC & DEP) have different net metering policies. In summary,

• Dominion offers 1-to-1 net metering where excess credits rollover month to month until the November billing period where they are credited at a low avoided cost rate (~3.8 cents). Dominion has a $14 minimum monthly bill.
• Duke Energy offers monthly net metering where excess credits may net 1-to-1 with consumption consumed only in the same billing cycle, and the same TOU period. Remaining excess credits at the end of the month are credited a low avoided cost rate (~3.8 cents), called the 'Net Excess Energy Credit.' Duke has a $30 minimum monthly bill among other nuances described below.

Dominion Energy (SC)

Rate 5 Time of Use

Dominion switches solar customers to Rate 5 TOU branded as You Shift/You Save Plan.

• Summer On-Peak Hours are 4pm-8pm
• Winter On-Peak Hours are 6am-9am
• Super Off-Peak Hours are 1am-5am (year-round) & noon-3pm in the winter
• Off-Peak Hours are all other times

Dominion on-peak hours are 4pm-8pm in summer
& 6am-9am in winter (weekdays only)

Time of Use rates can be beneficial for customers who can shift some of their energy usage away from on-peak hours, and utilize low-cost energy during discount hours.

• Off-peak periods are ~7 percent cheaper compared to the Standard rate.
• Super off-peak periods are ~40 percent cheaper compared to the Standard rate.

Tips on ways to shift and save

• Charge an electric vehicle overnight starting at 1am
• Reduce your air conditioning in the summer by pre-cooling your home before the 4pm peak begins…use a smart thermostat to set a schedule
• Reduce electric heat consumption if you have any during winter peak mornings
• Dry laundry during off-peak hours

Illustration of Rate 5 TOU

1-to-1 Net Metering per TOU period

Solar production will first power your home, and avoid grid purchases at the retail utility rate (the price per kWh you pay the utility). Any solar not immediately consumed or stored in a battery will be exported to the grid. Excess production will be tracked by Dominion for each TOU period.

Consumption from the grid will 'net,' or subtract, with excess Production for each TOU period. Excess On-Peak credits will net with On-Peak consumption 1-to-1. Excess Off-Peak credits will net with Off-Peak consumption 1-to-1. Any remaining solar credits will rollover to the next month until November.

Remaining Utility Bill

Even if solar provides 100% of your electricity needs, you will still have a utility bill to recover fixed customer charges that all consumers contribute to operate the grid. Rate 5 has a $14 per month Basic Facilities Charge. In addition, you will have a separate Palmetto bill for the solar system production.

Annual Cash Out

After the November billing cycle, your Dominion will credit any remaining net excess credits at the avoided cost per kWh rate. This value changes annually is currently 3.8 cents per kWh.

Utility rates adjust over time. The terms above are effective as of July 1, 2026. To learn more, visit Dominion Energy.

Duke Energy (SC)

Rate: Residential Solar Time of Use (R-STOU)

Duke Energy switches solar customers to rate Residential, Solar Time of Use (R-STOU).

• Summer On-Peak Hours are 6pm-9pm
• Winter On-Peak Hours are 6am-9am and 6pm-9pm
• Summer Months have a Super Off-Peak time of midnight - 6am
• Off-Peak Hours are all other times
• The rate includes Critical Peak Pricing, which means that for up to 20 days per year when electricity demand is at its highest, a higher critical peak rate will apply to the peak time period for that day.

Duke on-peak hours are 6pm-9pm year round,
& also 6am-9am December-February (weekdays only)

Time of Use rates can be beneficial for customers who can shift some of their energy usage away from on-peak hours, and utilize low-cost energy during discount hours. The easiest thing to remember in Duke is that peak is 6pm-9pm year round with the 3 months of winter also having 6am–9am peak.

Tips on ways to shift and save

• Charge an electric vehicle overnight starting at midnight
• Reduce your air conditioning by pre-cooling your home before the 6pm peak begins…use a smart thermostat to set a schedule
• Reduce electric heat consumption if you have any during winter peak
• Dry laundry during off-peak hours
• Add battery storage to your system to reduce peak consumption and solar exports by selecting a 'Self-Consumption' mode in the battery app
• Sign up for Critical Peak Pricing alerts from Dominion (texts and emails), and reduce usage during this 3 hour events as much as possible.

'Monthly' Net Metering

Solar production will first power your home, and avoid grid purchases at the retail utility rate. Any solar not immediately consumed or stored will be exported to the grid.

Electricity supplied to your home by Duke and excess solar production sent to the grid will be netted within each TOU pricing period 1-to-1. Excess On-Peak credits will net with On-Peak consumption. Excess Off-Peak credits will net with Off-Peak consumption.

At the end of the monthly billing period, any remaining solar credits will be credited at the current Net Excess Energy Credit rate of approximately 3.8-4 cents per kWh depending on the utility's annual avoided cost.

Example Monthly NEM Billing

• Net Energy Consumed during on-peak:
  • If during on-peak hours, 100 kWh are produced while 300 kWh are consumed, then 200 kWh will be charged the on-peak $/kWh retail utility rate.
• Excess Energy Generation during off-peak:
  • If during off-peak hours, 500 kWh are produced while 400 kWh are consumed, then -100 kWh will be credited the Net Excess Energy Credit of 3.8-4 cents per kWh.

Residential Solar Choice Fees

There are a few solar fees that apply to Duke Energy solar customers

1. Non-Bypassable Charge based on the solar system size

   • $0.45/kW DC per month in Duke Energy Carolinas (DEC)
   • $0.47/kW DC per month in Duke Energy Progress (DEP)
   • A typical 8 kW system would be charged $3.60 per month in DEC or $3.76 in DEP

2. Grid Access Fee - System Sizes over 15 kW DC (only applicable on large systems)

   • $5.86/kW per month for each kW over 15 kW DC (DEC)
   • $4.29/kW per month for each kW over 15 kW DC (DEP)
   • For example:
     • A system sized 8 kW would NOT have this fee
     • A 16 kW DC system would pay $4.29 per month in DEP

3. Minimum Monthly Bill

   • $30 per month

Minimum Monthly Bill

A Minimum Monthly Bill will apply in months when the distribution costs and the $13-15 Basic Facilities Charge do not total to at least the $30 Minimum Charge. It could apply in months where net consumption from the utility is low. Some months the minimum charge will not apply when the grid charges are already over $30.

Customer and distribution costs, like the existing Basic Facilities Charge, apply toward the minimum bill calculation. The Non-Bypassable Charge and supply charges do not count toward the minimum bill.

Bill Savings Estimator

To learn more about Residential Solar Choice and the R-STOU Time of Use rate, visit Duke Energy's website and give their solar bill savings estimator a try.

Utility rates adjust over time. The terms above are effective as of January 1, 2026.

Duke explanation of Residential Solar Choice

Duke Energy Battery Storage Incentive

Duke Energy has an optional battery storage incentive for customers with storage who agree to allow the utility to discharge the battery (up to a 20% minimum reserve level) during 30-36 peak events per year.

The program is called EnergyWise in Duke Energy Progress and Power Manager in Duke Energy Carolina, and more broadly known as a Virtual Power Plant program.

Duke Energy offers electricity bill credits for participating at $6.50/kW of continuous power, up to 20 kW, and adjusted for a 70.9% capability factor.

• For example, one Tesla Powerwall 3 (rated 11.5 kW) is eligible for $52/month or $624/year of participation.
• Larger battery systems may participate, however, the monthly utility bill credit will be capped based on 20 kW.
• All Palmetto approved batteries are eligible for the program. Duke estimates the incentive for each battery type on their website.

Enrollment

• Participation is completely voluntary. You choose to enroll.
• The incentive is received as monthly credits on your electric bill starting approximately 30 days after enrollment.
• After the system is installed, and Duke has issued Permission to Operate, you may enroll in the program. You will enroll through your battery equipment manufacturer, which most provide prompts in their mobile app.
• Start by selecting Enroll Now on Duke Energy's website at the links above.

Battery Control Events

Battery control events often occur on very hot or cold days when demand on the grid spikes. Duke and your battery manufacturer will send you texts or notifications when an event is about to occur. You do not necessarily have to reduce consumption, but it's possible it corresponds with Critical Peak Pricing events (high kWh rates) where you would want to reduce home consumption when possible.