Approved in 2007, Connecticut’s interconnection standard applies to distributed generation, including CHP, up to 20MW in size. This standard pertains to the two investor-owned utilities in the state, and separates distributed generation into three distinct tiers based upon system size. These tiers mirror those of FERC’s interconnection standards, upon which Connecticut’s standards are closely based.
Connecticut’s guidelines include a standard interconnection agreement and application fees that vary by system type. However, they are stricter than FERC’s standards and differ in several significant ways, including the requirement of an external disconnect switch and an interconnection transformer, the requirement for customers to indemnify their utility against “all causes of action,” and the requirement to maintain liability insurance in specified amounts based on the system’s capacity.
In January 2010, Maine’s Public Utility Commission (PUC) adopted interconnection procedures. These rules apply to all transmission and distribution utilities operating in Maine. The interconnection procedures set four tiers of review for interconnection requests for all eligible technologies and systems subject to Maine PUC jurisdiction. The four tiers are not subject to jurisdiction of the Federal Energy Regulatory Commission (FERC).
Massachusetts’ investor-owned utilities use an established interconnection process for all distributed generation, including CHP. There are three tiers of interconnection, corresponding with increased system scrutiny and fees. There is no set limit on system size, but a more extensive system impact study may be required on systems larger than 1MW, and is definitely required for systems larger than 5MW.
In 1999, New York became the second state in the country to adopt an interconnection standard and they have been periodically revised since. A 2015 REV Order directed the implementation of a process to raise the threshold applicability from 2 MW and the SIR was updated in March 2016 to apply to systems up to 5 MW. The standard is consistent with IEEE’s 1547 interconnection standard and explicitly allows for the interconnection of CHP systems. While the NYSIR interconnection standard applies up to 5 MW, the utilities with service territory covering the majority of the state have procedures that include systems up to 20 MW.
The New Hampshire Public Utilities Commission (PUC) established interconnection rules for net-metered systems up to 1 MW in January 2001. Systems that connect to the grid using inverters that meet IEEE 1547 and UL 1741 safety standards do not require an external disconnect device. However, the customer-generator assumes all risks and consequences associated with the absence of a switch. Utilities may not require customer-generators to perform additional tests, or pay for additional interconnection-related charges. Insurance is not required.
In 2011, the Rhode Island General Assembly passed General Law 39-26.3 “Distribution Generation Interconnection,” with the stated finding that “expeditious completion of the application process for renewable distributed generation is in the public interest. In November, 2011 the RI PUC adopted a tariff titled, “RIPUC #2078, Standards for Connected Distributed Generation,” for which CHP is eligible. The tariff is for renewable interconnecting customers as well as interconnecting customers, and, therefore, covers all forms of fuel. Additionally, the tariff applies to systems greater than 10 MW.
Under tariff #2078, National Grid offers a three-tiered (Simplified, Standard, and Expedited) interconnection processes for distributed generation, including CHP. A project’s review path is determined by project characteristics including generation type, size, customer load, and the characteristics of the grid where the system is to be located. Maximum total review days depend on review type, ranging from 15 days for a Simplified Review to 120-150 for a Standard review (usually complex projects). These standards were cited as supportive policies in the 2015 Energy Efficiency Program Plan which was approved by the Rhode Island PUC.
he Vermont Public Service Board (PSB) developed this interconnection rule for all distributed generation not subject to the state’s net metering rule. Rule 5.500, then, applies to all CHP systems. The PSB does not cap system size, though certain systems are eligible for a “fast track” application process. Systems not eligible for interconnection under the “fast track” mechanism are subject to additional studies and/or screening criteria.