The South Carolina Public Service Commission (PSC) adopted simplified interconnection guidelines for small distributed generation (DG) in December 2006. These guidelines address renewable-energy systems and other forms of DG up to 20 kilowatts (kW) in capacity for residential systems, and up to 100 kW for non-residential systems. Provisions for three-phase generators are not included.
South Carolina's interconnection guidelines apply to Progress Energy, Duke Energy, and South Carolina Electric and Gas.
There is a $100 application fee for residential systems and a $250 application fee for non-residential systems. Utilities may not require residential customers to carry liability insurance beyond the amount required by a standard homeowner's policy ($100,000 minimum coverage), but non-residential generators are required to carry comprehensive general liability insurance ($300,000 minimum coverage). Generators are responsible only for upgrade and improvement costs associated directly with a system's interconnection, but these costs may be determined by utilities. Utilities are prohibited from imposing indirect fees and charges. The guidelines include a mutual-indemnification requirement.
A redundant external disconnect switch is required, and the capacity of all interconnected generation is generally limited to a maximum of 2% of rated circuit capacity.