Solar on Dominion Energy SC

Why Dominion is the one set of terms you can actually look up

Dominion Energy South Carolina is an investor-owned electrical utility, which places it inside South Carolina’s net energy metering chapter and under Public Service Commission ratemaking. Its residential solar terms are set through a Commission process, and that process leaves a public record: filings, hearings, orders and an approved tariff.

That makes Dominion the only provider in our territory whose terms can be read from a document rather than confirmed by asking. It is also why almost every South Carolina solar page quotes Dominion’s figures, usually without saying so. If you are on a cooperative or on Santee Cooper, the number you have read somewhere is probably this utility’s and probably does not apply to you.

It cuts the other way too. Being tariffed means terms change through a visible process rather than quietly, but it does not mean they do not change. Programme structures for residential solar have been revised in South Carolina, and the arrangement that applies to a system depends on when it is interconnected. We confirm the current position rather than carrying last year’s forward.

Territory overlap around Charleston

Dominion’s Charleston-metro territory interleaves with Berkeley Electric Cooperative in a way that regularly catches people out. Daniel Island, where our office is, has both. Two houses on the same street can sit on different providers with materially different export terms.

This is the single most common source of a wrong quote in our market, and it is entirely avoidable. We read the provider off an actual bill rather than inferring it from an address, because on this side of the metro the address genuinely does not tell you.

If you are comparing quotes and one of them has not asked to see a bill, that is worth noting. There is no way to model a Charleston-area system correctly without establishing which side of that boundary the meter sits on.

What this means for system size

Where exported power is credited below the retail rate, the value of a system tilts towards self-consumption: a kilowatt-hour used as it is generated is worth the full retail rate you avoid paying, while a kilowatt-hour exported is worth whatever the export credit is. The wider that gap, the less sense it makes to oversize an array in order to bank credits.

That turns system sizing into a question about your usage pattern rather than your roof area. A household at home during the day, with electric water heating or a pool pump or an EV charging in daylight, converts far more of its production at the higher value. A household that is out all day and uses power in the evening does not, unless storage moves it.

It is also what makes battery storage a genuine question rather than an upsell here. Storage that shifts your own generation into your own evening is doing something with a measurable value; storage sold as a vague resilience benefit attached to a savings figure is not. We would rather quote those separately so you can see which one you are buying.

The 30% federal residential credit expired for systems placed in service on or after 1 January 2026, so it does not appear in our modelling. South Carolina’s 25% state credit on Form TC-38 does still apply, capped at $3,500 per tax year with a ten-year carry-forward.

How interconnection actually runs

Two separate approvals sit between a signed contract and a working system, and they are not the same thing. The building permit is local, issued by your city or county. The interconnection agreement is the utility’s, and it is what allows your system to be connected to their network and to export at all. We file both, but they run on different clocks and only one of them is predictable.

The interconnection application goes in with the system design, the equipment specifications and the single-line diagram. What follows is a review against the utility’s technical requirements, and the timeline depends on their queue rather than on anything the installer controls. An installer who promises you a specific interconnection date is promising something that is not theirs to promise.

After installation there is an inspection, and then the utility issues permission to operate. Until that arrives, the system is physically complete and producing nothing, because it stays switched off. This is the stage that generates the most frustration, and it is the reason we say the timeline plainly at the quote rather than at the handover.

If a quote you are comparing does not distinguish between installation time and time to permission to operate, it is describing the easy half. Ask which number you are being given.

What we confirm before we model anything

We read your provider off an actual bill rather than inferring it from a postcode. In the Charleston metro particularly, territory boundaries run between streets and sometimes down them, and a postcode-level assumption is how a quote ends up modelling the wrong export credit entirely.

We confirm the current export arrangement that applies to your meter, and the rate schedule you are on. A provider can have more than one, and the relationship between what you pay and what you are credited is the number that drives everything downstream: system size, whether storage earns its place, and what payback honestly looks like.

We use twelve months of your own usage, not an average. A system sized from a single summer bill is oversized for the year; one sized from a mild month underperforms every August. The shape of your usage across the day matters as much as the total, because where export credits sit below retail, the power you consume as you generate it is worth more than the power you send out.

And we confirm what has changed. Export terms, rebate availability and programme caps are all revisable, and several have been revised in our territory. We would rather re-check before quoting than carry a figure forward because it was true last year.

Reading a competitor quote on this utility

Check the export assumption first. It is usually not stated outright; it is buried in the savings projection. If two quotes show different twenty-five year totals for a similar system, the difference is far more likely to be the export and escalation assumptions than the panels.

Check whether the 30% federal credit has been subtracted. It expired for systems placed in service on or after 1 January 2026, and proposals built on older templates still carry it. A quote that nets it out is overstating your position by a large margin, and it is the single most common error we see on competitor paperwork right now.

Check the production figure in kilowatt-hours. A dollars-saved headline embeds assumptions about both the export rate and future rate rises; a kilowatt-hour figure can be checked against your own bill and against the roof. Ask for the production estimate and the assumptions separately.

Check who performs the work and who holds the warranty. A large share of residential solar in the Southeast is sold by one company and installed by a subcontractor. That matters the day a penetration needs revisiting. Our crews are our own and the roof-penetration warranty is ours.