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Vermont Interconnection Standards

Date Last Updated11/16/2012
Policy TypeInterconnection Standard
Policy Administrator/Contact OfficeVermont Public Service Board (PSB)
Policy Initiation Date9/10/2006
Policy SummaryThe PSB has separate interconnection standards for net-metered systems up to 150 kW, and distributed generation (DG) including CHP systems that are not net-metered (no size limit specified).

Net-Metered Systems up to 150 kW: Utilities must offer net-metering to all customers with photovoltaic, wind, fuel cells, or biomass systems until the cumulative generating capacity of net-metered systems equals 4% of a utility's peak demand. The following key provisions apply to all net-metered, interconnected systems up to 150 kW:
  • All systems must have a utility-accessible, lockable disconnect switch--unless the system is inverter based and the utility has waived the requirement in writing and in the case of small systems (<500 watts), where a lockable disconnect plug unit is acceptable if the customer files a proper application with the utility. The disconnect plug must be able to break load and must be utility-accessible.
  • Systems will be tested initially upon installation and once every 2 years to determine that anti-islanding controls are functioning correctly.
  • System owners must carry a minimum of $100,000 in general liability insurance for residential systems and $300,000 for non-residential sites.
Net-metered systems must first complete an application for a "Certificate of Public Good for Interconnected Net-Metered Power Systems," or register as a "Photovoltaic Systems that Are 10 kW (AC) or Less in Capacity," both of which are available on the Public Service Board's website. The maximum system capacity for net-metered systems is 500 kW (details for net-metered systems between 150 and 500 kW are below).

Interconnection Requirements for Other Systems: The PSB established standards for systems up to 50 MW that are not net-metered and not subject to Independent System Operator of New England (ISO-NE) interconnection rules or successor rules approved by the Federal Energy Regulatory Commission (FERC). The PSB's DG including CHP interconnection rule does not specify a maximum system capacity. Utilities are required to designate an employee or office from which customers may obtain information regarding the application process. There is a standard application form and a nonrefundable application fee of $300.

DG including CHP systems that meet certain technical screening criteria are eligible for the "fast track" interconnection process, which requires no special studies. Systems not eligible for "fast track" interconnection require a feasibility study, a system-impact study, and/or a facilities study. Reasonable, specific timelines apply to "fast track" interconnection and general interconnection. During the interconnection process, either party may petition the PSB for a dispute resolution.

A manual external disconnect switch is required. Systems must comply with an array of standards, including IEEE 1547 and UL 1741. Any equipment package will be considered certified for interconnection if it has been submitted, tested and listed by a nationally recognized testing and certification laboratory or approved by the U.S. Department of Energy.

The PSB has developed model interconnection documents. However, a customer and utility may also enter voluntarily into different arrangements.
CHP Eligibility RequirementsBoth fossil-fueled and renewably-fueled CHP systems are eligible for standardized interconnection.
Eligible Project Size (MW)All sizes are eligible for standardized procedures.
Applicable FormsApplicable forms can be found here.
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