If you are a North Carolina Duke Energy customer shopping for solar plus a home battery in 2026, the headline PowerPair number is “up to $9,000.” The number that actually matters for the battery itself is smaller.

On a typical Tesla Powerwall 3 (13.5 kWh / 11.5 kW), our calculator’s default math shows a $5,400 battery rebate, about $636 a year in Battery Control credits, a modeled $117 in time-of-use bill savings, and a cash payback of about 12.5 years on the battery add-on — after the rebate, with no federal residential clean energy credit. Those figures are a model, not a guarantee.

How the PowerPair rebates work

PowerPair is a North Carolina-only pilot from Duke Energy Carolinas and Duke Energy Progress. The North Carolina Utilities Commission approved it on January 11, 2024, in Docket E-7, Sub 1261 and Docket E-2, Sub 1287. Capacity is limited to 30,000 kW-AC of solar in each territory, and enrollment is first come, first served. The system has to be installed by a Duke-approved Trade Ally. If it is already operating, the application generally must be in within 90 days of the operational date.

The “up to $9,000” cap is two separate rebates:

  • Solar: $0.36 per watt-AC, capped at 10 kW-AC, or $3,600.

  • Battery: $400 per kWh, capped at 13.5 kWh, or $5,400.

A Powerwall 3 hits the battery cap exactly, so the storage rebate is $5,400. The $3,600 solar rebate offsets the panels and should not be subtracted from the battery’s cost. The upfront rebate is only for a new paired solar-plus-battery system. Adding a battery alone, or adding panels onto existing solar, does not qualify. A standalone battery can still be enrolled for monthly Battery Control credits, but it does not get the $5,400.

You also agree to stay in the program for 10 years. Leave early — for example by removing the equipment — and Duke can require a pro-rated repayment, unless it finds good cause, which the terms say can include selling the home.

What you give Duke in return

To get the rebate, you enroll on either the Net Metering Bridge rider (Rider NMB) or the Residential Solar Choice rider (Rider RSC). You generally have to stay on the rider you pick for 24 months, and you may switch only twice in the 10-year term.

The monthly bill credit is paid only if you enroll in Battery Control: Power Manager for Duke Energy Carolinas, or EnergyWise Home for Duke Energy Progress. That enrollment is required on the Net Metering Bridge rider. If you take Residential Solar Choice, confirm with Duke whether you will be in Battery Control. A data-only track does not receive the monthly credit.

The credit is not a flat $6.50 times the battery’s nameplate kilowatts. Manufacturer FAQs state the formula as $6.50 per kW of nameplate continuous discharge, multiplied by a capability factor that is currently 70.9% and can change. On an 11.5 kW Powerwall 3, that is 11.5 × $6.50 × 0.709, or $53.00 a month ($636 a year). Duke’s Trade Ally battery table currently lists that same Powerwall 3 at $52 a month ($624 a year), a rounding difference on the same formula.

In exchange, Duke can charge, discharge, or hold the battery during 30 to 36 events a year, and not below a 20% state of charge. Customers may opt out of up to four events each year. On the Net Metering Bridge rider there is also a minimum bill of $22 a month for Duke Energy Carolinas and $28 a month for Duke Energy Progress, and the Battery Control credit can be applied toward it.

A worked example: adding one Powerwall 3

This is the default scenario in our Duke Energy PowerPair calculator: a new paired solar-plus-battery system, one Tesla Powerwall 3, and a 20% backup reserve.

An estimated $14,800 installed cost, minus the $5,400 PowerPair battery rebate, leaves a net battery cost of $9,400. The separate $3,600 solar rebate is left out of this payback, because it offsets the panels. Year-1 value is $753: $636 in Battery Control credits using the 70.9% factor, plus about $117 of modeled time-of-use savings. That TOU figure is a modeling estimate, not a filed Duke tariff price. Simple cash payback is $9,400 divided by $753, or about 12.5 years. If those amounts hold, the calculator’s 10-year modeled total is $12,931.

Federal Section 25D, the 30% residential clean energy credit, is not in this math. Under Public Law 119-21, that credit does not apply to expenditures made after December 31, 2025. The IRS has also said that paying in 2025 is not enough if installation is completed after that date. The calculator therefore defaults to a 0% federal credit for a homeowner-owned 2026 installation.

What changes the payback

The upfront battery rebate stops at 13.5 kWh, so a larger pack does not earn a larger installation check. The monthly credit is based on nameplate discharge kilowatts, so a higher-discharge battery can earn more each month. Duke’s Trade Ally table posts the credit for each approved model.

The $117 TOU figure is only a modeled spread, not a copy of Rider RSC prices. Actual rates, the rider you are on, and how much energy you can shift will change the bill savings. Raising the backup reserve above 20% also cuts the modeled TOU savings. A cheaper or more expensive quote than the $14,800 estimate moves the 12.5-year payback almost dollar for dollar, as does any change in the 70.9% capability factor.

Who this is a good deal for — and who it isn't

PowerPair is most useful for a North Carolina homeowner who is already installing new solar with a Trade Ally, wants backup power, and

It is a weaker cash deal if you expected the old 30% federal credit to carry the numbers, if you are only adding a battery to existing solar, or if you need the full pack held in reserve at all times. South Carolina Duke customers are outside the pilot, and a reservation is not guaranteed until Duke approves your application under the 30,000 kW-AC cap. Backup value is real, but it is not in the 12.5-year figure.

How to check your own numbers

Use the calculator linked above with your battery model, your installed price, and the backup reserve you actually want. Then get a written Trade Ally quote and ask Duke whether capacity is still open, which rider you will be on, and what monthly credit is listed for your equipment. Compare that credit with the 70.9% formula so you are not using a raw $6.50-per-kW quote that skips the factor.

Program rules, the capability factor, and remaining capacity can change. Confirm the current terms on Duke’s PowerPair Trade Ally page and, for the federal credit, the IRS FAQ on Section 25D under Public Law 119-21 before you sign. For other utility battery and rate calculators, see the GridPayouts utilities directory.