860-039-0040 Tier 4 Net Metering Interconnection Review (1) The public utility must apply the Tier 4 review procedure for an application to interconnect a net metering facility that meets the following criteria: (a) The facility has a capacity of two megawatts or less; and (b) The facility does not qualify for or failed to receive approval in Tier 1 or Tier 2 interconnection review procedures. (2) Following receipt of a Tier 4 application and within three business days of a request from the applicant, the public utility must provide pertinent information to the applicant, such as the available fault current at the proposed interconnection location, the existing peak loading on the lines in the general vicinity of the net metering facility, and the configuration of the distribution lines at the proposed point of common coupling. (3) Within seven business days after receiving a complete application for Tier 4 interconnection review, the public utility must provide an impact study agreement to the applicant, which will include a non-binding, good faith cost estimate for an impact study to be performed by the public utility. The impact study will be conducted in accordance with good utility practice and must: (a) Detail the impacts to the electric distribution system that would result if the net metering facility were interconnected without modifications to either the net metering facility or to the electric distribution system; (b) Identify any modifications to the public utility's electric distribution system that would be necessary to accommodate the proposed interconnection; (c) Focus on power flows and utility protective devices, including control requirements; and (d) Include the following elements, as applicable: (A) A load flow study; (B) A short-circuit study; (C) A circuit protection and coordination study; (D) The impact on the operation of the electric distribution system; (E) A stability study, along with the conditions that would justify including this element in the impact study; (F) A voltage collapse study, along with the conditions that would justify including this element in the impact study; and (G) Additional elements, if approved in writing by Commission staff prior to the impact study. (4) After the applicant executes the impact study agreement and pays the public utility the amount of the good faith estimate, the public utility will complete the impact study and will notify the applicant within 30 calendar days of one of the following results: (a) Only minor modifications to the public utility's electric distribution system are necessary to accommodate interconnection. In such a case, the public utility will send the applicant an interconnection agreement that details the scope of the necessary modifications and a non-binding, good faith estimate of their cost; or (b) Substantial modifications to the public utility's electric distribution system are necessary to accommodate the proposed interconnection. In such a case, the public utility must provide a non-binding, good faith estimate of the cost of the modifications, which must be accurate to within plus or minus 25 percent. In addition, the public utility must offer to conduct, at the applicant’s expense, an interconnection facilities study that must identify the types and cost of equipment needed to safely interconnect the applicant's net metering facility. (5) If the proposed interconnection may affect electric transmission or delivery systems other than those controlled by the public utility, operators of those other systems may require additional studies to determine the potential impact of the interconnection on those systems. If such additional studies are required, the public utility will coordinate the studies but will not be responsible for their timing. The applicant will be responsible for the costs of any such additional studies required by another affected system. Such studies will be conducted only after the applicant has provided written authorization. (6) If an applicant requests a facilities study under subsection (4)(b), the public utility must provide an interconnection facilities study agreement. The interconnection facilities study agreement must describe the work to be undertaken in the interconnection facilities study and must include a non-binding, good faith estimate of the cost to the applicant for completion of the study. Upon the execution by the applicant of the interconnection facilities study agreement, the public utility will conduct an interconnection facilities study to identify the facilities necessary to safely interconnect the net metering facility with the public utility's electric distribution system, and to propose a non-binding, good faith estimate of the cost of those facilities and the time required to build and install those facilities. (7) Upon completion of an interconnection facilities study, the public utility must provide the applicant with the results of the study and an executable interconnection agreement. The agreement must list the conditions and facilities necessary for the net metering facility to safely interconnect with the public utility's electric distribution system, and must include a non-binding, good faith estimate of the cost of those facilities and the estimated time required to build and install those facilities. (8) If the applicant wishes to interconnect, it must execute the interconnection agreement and return it to the public utility at least 10 business days prior to starting operation of the net metering facility (unless the public utility does not so require), pay a deposit of not more than 50 percent of the estimated cost of the facilities identified in the interconnection facilities study, complete installation of the net metering facility, and agree to pay the public utility the actual installed cost of the facilities needed to interconnect as identified in the interconnection facilities study. (9) Within 15 business days after notice from the applicant that the net metering facility has been installed, the public utility will inspect the net metering facility and will arrange to witness any commissioning tests required under IEEE standards. The public utility and the applicant will select a date by mutual agreement for the public utility to witness commissioning tests. (10) If the net metering facility satisfactorily passes required commissioning tests, if any, the public utility must notify the applicant in writing, within three business days after the tests, of one of the following: (a) The interconnection is approved, and the net metering facility may begin operation; or (b) The interconnection facilities study identified necessary construction that has not been completed, the date upon which the construction will be completed and the date when the net metering facility may begin operation. (11) If the commissioning tests are not satisfactory, the applicant will repair or replace the unsatisfactory equipment and reschedule a commissioning test. Statutory/Other Authority: ORS 183, ORS 756 & ORS 757 Statutes/Other Implemented: ORS 756.040 & ORS 757.300 History: PUC 3-2024, amend filed 04/09/2024, effective 04/09/2024 PUC 8-2007, f. & cert. ef. 7-27-07