Avista Utilities - Interconnection Guidelines

March 21, 2007


Idaho has not established uniform interconnection rules and procedures either for net-metered systems or for larger distributed-generation (DG) systems that are not net-metered. However, through their respective tariffs, each of the state's three investor-owned utilities -- Avista Utilities, Idaho Power and Rocky Mountain Power -- has established guidelines for the interconnection of small renewable-energy systems and larger DG. Avista Utilities' interconnection guidelines for net metering, included in Schedule 63 and Schedule 70, do not specify technical requirements in detail. For net-metered systems, an external disconnect switch is required, and all equipment must meet applicable safety, power quality and interconnection requirements established by the National Electrical Code (NEC), National Electrical Safety Code (NESC), the Institute of Electrical and Electronics Engineers (IEEE), and Underwriters Laboratories (UL). Net metering is generally available to customers who generate electricity using a renewable-energy system up to 25 kilowatts (kW) in capacity. Avista Utilities also has also developed interconnection guidelines for DG systems up to 300 kilowatts (kW) in capacity. There is a $100 application fee for proposed systems. An external disconnect switch is required, and a separate transformer may be required. No additional insurance is necessary for systems powered by solar, wind, hydropower or fuel cells, but additional insurance and indemnification may be required for other systems. Systems must comply with all applicable codes and standards for safe and reliable operation, including the NEC, NESC, IEEE, ASNI and UL. Interconnection to network distribution systems may be permitted if the customer provides evidence that a proposed system will not result in reverse current flow. The interconnection of Qualifying Facilities (QFs)* up to 10 average megawatts in capacity is addressed briefly by the utility's Schedule 62. In an order issue January 24, 2007, the Idaho Public Utilities Commission ruled that the National Association of Regulatory Utility Commissioners (NARUC) interconnection model should be used as a "guideline" for interconnection agreements. * This term, defined in the Public Utility Regulatory Policies Act of 1978 (PURPA), generally includes renewable-energy systems and combined-heat-and-power (CHP) systems.

Program Overview

Implementing Sector: Utility
Category: Regulatory Policy
State: Idaho
Incentive Type: Interconnection
Web Site: http://www.avistautilities.com/products/renewable_generation.asp
Start Date:
Eligible Renewable/Other Technologies:
  • Solar Thermal Electric
  • Solar Photovoltaics
  • Wind (All)
  • Biomass
  • Hydroelectric
  • Combined Heat & Power
  • Fuel Cells using Non-Renewable Fuels
  • Wind (Small)
  • Fuel Cells using Renewable Fuels
  • Other Distributed Generation Technologies
Applicable Utilities: Yes
System Capacity Limit: 25 kW for net-metered systems; 10 average MW for qualifying facilities that are not net-metered
Insurance Requirements: Not specified
External Disconnect Switch: Yes
Net Metering Required: Yes (utility guidelines)


Name: Rick Sterling
Organization: Idaho Public Utilities Commission
Address: 472 W. Washington
Boise ID 83720-0074
Phone: (208) 334-0351
Email: rick.sterling@puc.idaho.gov

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.