Greenville Utilities Commission sets your rules, not Duke
Greenville Utilities Commission is the municipal utility here. North Carolina has 76 municipally-owned electric utilities, and municipal electric providers and Electric Membership Cooperatives are not regulated by the North Carolina Utilities Commission, unlike investor-owned utilities.
That means the well-known changes to Duke Energy's arrangements, its move away from legacy flat retail net metering for new residential customers and onto time-differentiated or bridge rate options, are not the story in Greenville. They describe a utility you are not a customer of. Most published North Carolina solar advice is about Duke, and applying it here will give you the wrong answer.
Start by reading the name on your bill. If it says Greenville Utilities Commission, then the terms that matter to you are GUC's own, published by GUC, and a figure from anywhere else is a starting point for a question rather than an answer.
It is also a quick way to judge an installer. Someone who has worked in Greenville will know the arrangements by name and will ask which one you want before quoting. Someone who opens with Duke's net metering has not filed an interconnection application here.
The battery question decides which arrangement you can have
GUC's Net Billing arrangement, which it describes as Renewable Excess Energy Buy Back Bi-Directional Metering, is available to residential customers installing a renewable generation system of 20 kW-AC or less. Generated energy offsets what you consume from GUC first, you are billed for energy consumed at the Retail Rate, you are credited for excess energy supplied to GUC at the Avoided Rate, and battery storage is permitted.
The Buy All, Sell All Bilateral Metering arrangement is also available to residential customers at 20 kW-AC or less. Under it, all energy generation is supplied directly to GUC, and battery storage is not permitted.
That last clause deserves more attention than it usually gets. A homeowner who takes Buy All, Sell All because the credit arithmetic looked simpler, and who later wants a battery for outage cover, has closed off that option under the arrangement they signed. Ask GUC what changing arrangements later involves before you choose, rather than after.
The two structures also reward completely different behaviour. Under Net Billing, generation you consume yourself displaces electricity at the Retail Rate, so daytime usage is worth shifting. Under Buy All, Sell All, everything you generate has already gone to GUC, so running appliances in daylight does nothing. Make sure the quote in front of you models the arrangement you actually intend to be on.
A 20 kW-AC ceiling and a $250 application fee
For residential customers the maximum size system allowed is 20 kW-AC. That is roomier than several other North Carolina municipal utilities allow, and it will not constrain most homes, but it is a firm number to design against rather than discover late.
The application fee is $250, billed against the customer's account as a one-time Electric Solar Interconnection Fee at the time an application is received. Note the timing: the fee attaches when the application arrives, not when the system is switched on. Establish in writing whether your installer is paying it and passing it through, or whether it lands on your account directly.
GUC also lists a Time of Use with Demand Net Metering arrangement alongside the two above. Ask GUC directly which arrangements a new residential solar customer at your address can choose between today, since the answer determines everything downstream and it is a short phone call on 855-767-2482.
Ask for the terms in writing, particularly the Avoided Rate used to credit exports under Net Billing. An avoided-cost rate is a moving number rather than a fixed tariff, and a payback calculation built on last year's figure is not one to sign against.
What the state still gives you, and what the federal government no longer does
North Carolina excludes most of the added assessed home value of a residential active solar heating, cooling or electric system from property tax. The improvement does not raise your tax bill the way a renovation of similar cost would, and it applies whoever your utility is. There is nothing to file for it, which is exactly why it gets left out of people's arithmetic.
The federal picture has changed. The 30 percent residential tax credit under Section 25D applied through December 31, 2025 and is not available for a purchased home system placed in service after that date. A quote that still applies it is overstating your return substantially.
If you take a lease or a power purchase agreement instead of buying, the provider may claim the business version of the credit under Section 48E and reflect part of that value in the rate they offer. What they claim and what actually reaches you are different questions, so put both to the provider and confirm with a tax advisor rather than with the sales material.
Be careful with a neighbour's reported payback as well. Someone who connected earlier had the federal credit, and may be on a different GUC arrangement than the one open to you now. Their figures are accurate for their project and are not a guide to yours.