Interconnection Standards

April 25, 2006

Summary

Kentucky enacted statewide net-metering legislation (SB 247) in April 2004, requiring all investor-owned utilities and rural electric cooperatives to offer net metering to customers with solar-electric (PV) systems of 15 kilowatts (kW) or less. TVA utilities are exempt from this law. Utilities have since filed tariffs with the Kentucky Public Service Commission (PSC) that include all terms and conditions of their net-metering programs, including interconnection standards. Two Kentucky utilities -- Kentucky Utilities (KU) and Louisville Gas and Electric (LG&E) -- that previously offered pilot net-metering programs offer net metering to customers with wind and hydroelectric systems. Interconnection rules for net-metered systems include the following key provisions:

• System owners must have liability insurance of at least $100,000.
• A manual, lockable, external disconnect switch is required.
• Systems and interconnecting equipment must meet all applicable safety and power quality standards established by the National Electrical Code (NEC), the Institute of Electrical and Electronics Engineers (IEEE), and accredited testing laboratories such as Underwriters Laboratories (UL).

Additionally, KU; LG&E; and Union Light, Heat and Power Company (ULH&P) have filed cogeneration interconnection tariffs for qualifying facilities (QF) and other systems up to 100 kW. KU and LG&E have identical rules, which offer little technical detail and provide utilities with full discretion over the approval process. National standards or procedural timetables are not referenced. The ULH&P tariff is similarly focused on larger systems but includes details in the company's "Guideline Technical Requirements for Parallel Operation of Customer Generation on the Transmission System."