Rules by state

Solar and battery interconnection rules in South Carolina

South Carolina generator interconnection procedures. Every threshold below was read out of the document linked at the bottom of this page, and the same rules answer the free screening check.

Who this binds: investor owned utilities. A utility outside that list sets its own terms, so confirm who serves the address first.

Check a South Carolina address free
How the size is measured

nameplate capacity: the manufacturer nameplate rated output capability of the generator, based on alternating current. For an inverter based facility the maximum rated capacity is the sum of the inverters maximum rated capacity in alternating current. The array direct current size does not place the project.

Size bands and what each one obliges

20 kW inverter process Size 0 to 20 kW

A facility no larger than 20 kW. The fee is $100, the cheapest small application in the southeastern states. Residential insurance at or below 250 kW is a homeowner policy of at least $100,000 per occurrence. Review completes in 15 business days.

  • $100 application fee
  • $100,000 per occurrence homeowner policy for residential
Fast track, above 20 kW to 100 kW Size 20.001 to 100 kW

The fee is $250. Non residential insurance at or below 250 kW is at least $300,000 per occurrence.

  • $250 application fee
  • $300,000 per occurrence for non residential
Fast track, above 100 kW to 2 MW Size 100.001 to 2000 kW

The fee is $500. Above 250 kW insurance rises to at least $1,000,000 per occurrence. South Carolina charges nothing for a fast track study at this tier.

  • $500 application fee
  • $1,000,000 per occurrence above 250 kW
Serial study process, above 2 MW Size 2000.001 kW and above

An interconnection facilities deposit charge of $10,000 plus $1 per kW AC applies, inclusive of a $1,000 fee to administer the study process.

  • $10,000 plus $1 per kW AC deposit
  • $1,000,000 per occurrence insurance

The screens that decide it

Ask the utility this, before you sell it

  1. How much of the reserved circuit phase capacity is already used on this circuit? South Carolina publishes a reserved capacity table of 150 kW per phase below 10 kV, 450 kW from 10 to 15 kV and 500 kW from 15 to 25 kV, and once it is exceeded every later request on that circuit goes to fast track. A 15 kW residential job can be bumped out of the cheap lane by the neighbors rather than by its own size, which no other state in this region publishes.
  2. Is this address served by Santee Cooper or an electric cooperative? Santee Cooper has its own standard and cooperatives are outside these procedures.
  3. What is the current Solar Choice Metering compensation for this customer?

Worth knowing before you quote

South Carolina has the clearest basis of measurement definition of any state read, naming the sum of inverter alternating current ratings explicitly. The 2021 revision added a maximum physical export capability field and requires 8760 hour projections for total facility output with storage, which is a limited export pathway in all but name. The Act 236 two percent net metering cap was addressed by Act 62 in 2019 and replaced by Solar Choice Metering tariffs effective 1 June 2021 on an interim basis and 1 January 2022 permanently.

Utility programs we have read in South Carolina

Source

South Carolina Generator Interconnection Procedures, Forms and Agreements for state jurisdictional interconnections, effective 18 June 2021, Public Service Commission of South Carolina Docket 2019-326-E, Order 2021-439

Read and recorded 2026-09-12. Promulgated by the Commission and binding on Duke Energy Carolinas, Duke Energy Progress, Dominion Energy South Carolina and Lockhart Power. Santee Cooper publishes its own separate generator interconnection standard and is not bound by these procedures. Electric cooperatives are outside them.

What to do with this

Check a real address

The rules below are the general case. Run the free check to see which utility serves a specific address, which tier the system lands in, and what to ask.

Run the free check
Installers: keep the answer with the job

GridProjeX holds the project from here, with every value tied to the document it came from and the utility and permit tracks run to permission to operate.

How it works for installers
Utilities: see what applicants are told

The same published rules your applicants read here are the ones your queue sees. GridProjeX is the record both sides work from.

How it works for utilities

Also from CivyxIQ, if they fit what you already do: SolarProjeX for running the crews and the jobs, and Solar Home so the homeowner can follow their own project. Neither is needed to use the checker.