Ask the utility which tariff the address is on
South Carolina no longer offers simple one-to-one retail net metering to new solar homes. Solar choice metering rates became available to consumers applying for new service on or after June 1, 2021 and are available for ten years, with export value tied to time-of-use rates.
Existing customers who enrolled earlier continue to receive one-to-one compensation into 2029 depending on when they initially enrolled. If the house you are buying has an older system, it may be on that better arrangement.
Ask the utility directly what arrangement the property is on, how long it runs, and whether it transfers to a new owner. Ask in writing and before closing, because the answer can affect what the system is worth to you by a large margin.
Ask also what would happen if the system were expanded or replaced. Modifying an existing system can move it onto current terms, so if you are planning to add panels or a battery, find that out before you buy rather than after.
And who owns the array
Establish whether the system is owned outright, financed with a loan, or subject to a lease or power purchase agreement. Those are three different situations and only the first is straightforward.
If there is a loan, find out whether it is being settled at closing or whether anything is expected to pass to you, and get that in writing as part of the transaction.
Under a lease or a power purchase agreement you do not get the array by buying the house. A third-party owner holds it and you would generally have to qualify for and assume the agreement, so ask for the agreement itself and read the transfer terms and the buyout cost.
Ask about the state tax credit too. It is claimed by the taxpayer who installed the system on Form TC-38 and has a 10 year carryforward, so ask what the position is rather than assuming any unused credit comes with the house.
Condition, documentation and warranties
Ask for the permits, the inspection sign-offs, the interconnection approval and the equipment specifications with model numbers. A system without documentation is difficult to warranty, difficult to service and difficult to sell on again.
Establish who honours each warranty and how much term remains. Panels, inverter and workmanship are commonly covered by three different parties, and a company that has left the market cannot support a workmanship warranty however well written.
Ask about the roof underneath. If the covering is near the end of its life you will eventually pay to remove and reinstall the array, which is a real cost attached to the house that a listing will not mention.
Ask for production history if any exists. Actual generation over a year or two is far better evidence than a projection, and a system that has quietly underperformed is worth knowing about while you can still act on it.
The state credit, and how much of it you will actually use
South Carolina offers a state income tax credit of 25 percent of the total system cost, up to a total credit of $35,000, claimed on Form TC-38. That headline is genuinely generous and it is the main reason solar still works here now that the federal residential credit has gone.
The limit that decides what it is worth to you is annual. A taxpayer may use only $3,500 of the credit in a year, or 50 percent of their state tax liability, whichever is less, and the excess for each facility can be carried forward for 10 years.
So a household with modest South Carolina tax liability may not use the whole credit within the carryforward period. That is not a reason to avoid it, but it does mean the number in a sales presentation and the number you receive can differ substantially. Ask a tax advisor how much you would realistically realise given your own liability.
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase now receives no federal credit. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so ask any such provider what they claim and what of that value reaches you.