B. Background on Technical Review Processes
Typical interconnection technical review processes apply a tiered review approach that offers multiple review paths which increase in complexity depending on the project’s characteristics. This approach is utilized in FERC SGIP and a similar basic framework is used across state jurisdictions regardless of whether the process is modeled off of SGIP, IREC’s Model, or another template. Most jurisdictions have both a screening and a study process.
The screening processes are designed to use a set of conservative screens to determine whether there is any probability that a project will result in distribution system impacts. If a project passes the screens, this indicates there is no need for a full interconnection study because there is little probability that it will cause distribution system impacts. Projects that fail the screens, or are not eligible for the screening process due to their size, proceed to a series of interconnection studies that more thoroughly analyze whether distribution system impacts will arise, identify whether upgrades are needed, and determine the costs of those upgrades if needed.
The screening process is often split into multiple different tiers as well. SGIP and most state procedures have an expedited pathway for small (10-50 kW) certified inverter-based projects (often called the simplified, expedited, or Level 1 process; for the remainder of this discussion, it will be referred to as the Simplified process). Some states use fewer screens in the Simplified process,((IREC 2019 Model § III.A.2., III.B.2 (Level 1 uses fewer screens than Level 2); MA Dept. of Public Util., Eversource Energy, Standards for Interconnection of Distributed Generation, p. 47 (Sept. 15, 2021) (Figure 1 shows that the Simplified process uses fewer screens than expedited process), https://www.eversource.com/content/docs/default-source/rates-tariffs/55.pdf; 199 IA Administrative Code 45.8-45.9 (Level 1 uses fewer screens than Level 2).)) but SGIP and most states apply the same screens used for larger projects.((FERC SGIP, Attachment 5: Application, Procedures, and Terms and Conditions for Interconnecting a Certified Inverter-Based Small Generating Facility No Larger than 10 kW (“10 kW Inverter Process”), § 4.0 (simplified 10 kW Inverter Process uses the same screens as the Fast Track process); NC Util. Comm., Dkt. E-100, Sub 101, North Carolina Interconnection Procedures § 2.2.1 (Aug. 20, 2021) (Simplified 20 kW Inverter Process uses the same screens as Fast Track process), https://desitecoreprod-cd.azureedge.net/_/media/pdfs/for-your-home/212287/ncip-approved-oct-15-2020.pdf?la=en&rev=cd85b126dd0345019917e2464beb861b. UT Admin. Code R746-312-7 (Level 1 and Level 2 use the same screens).))
The next tier is commonly known as the Fast Track or Level 2 process (hereinafter referred to as Fast Track). Under this process, the project is subject to an initial set of screens, and if it fails any of those screens, it may have the option to proceed to a Supplemental Review process. Some states and SGIP have defined screens for the Supplemental Review process, while in other states it is more open-ended.((4 Code of CO Regulations 723-3, Rule 38655(d)(VI) (defining the Supplemental Review screens); North Carolina Interconnection Procedures § 3.4 (no defined Supplemental Review screens). FERC SGIP and IREC 2019 Model both define Supplemental Review screens. FERC SGIP § 2.4.4; IREC 2019 Model § III.D.))
Some states also have a distinct process for non-exporting projects, often called the Level 3 process. Level 3 typically uses the same screens as Fast Track, but allows larger projects and may use a shorter review period.((199 IA Administrative Code 45.7(3) (non-export DERs qualify for Level 3 review that includes fewer screens than Fast Track); Code MD Regs. 20.50.09.11(C)-(D) (Non-export DERs qualify for Level 3 review that includes most of the same screens as Fast Track, except the penetration screen uses 25% of peak load rather than 15% of peak load); AZ Administrative Code § R14-2-2623(B)-(C) (expedited process for small non-exporting DER using the same screens as Fast Track).))
Projects that pass through any of the screening processes can go directly to an interconnection agreement, while those that fail have the option to withdraw or proceed to the full study process.((Electric Power Research Institute, Independent Assessment of Duke Energy’s Fast Track Review Process for DER Interconnection, (Oct. 2019) https://www.epri.com/research/products/000000003002017329.)) The full study process typically consists of a series of studies((FERC SGIP has a series of three: feasibility, system impacts, and facilities. FERC SGIP §§ 3.3-3.5. Some states also provide for three distinct studies, though it is now becoming more common to eliminate the feasibility study and proceed directly to a system impacts study. NC Util. Comm., Dkt. E-100, Sub 101, North Carolina Interconnection Procedures §§ 4.3-4.5 (no feasibly study); MN Pub. Uilt. Comm., Dkt. E-999/CI-16-521, Order Establishing Updated Interconnection Process and Standard Interconnection Agreement, Attachment: Minnesota Distributed Energy Resources Interconnection Process (MN DIP) §§ 4.3-4.4 (Aug. 13, 2018) (no feasibility study); NJ Admin. Code 14:8-5.6 (no feasibly study). Some states, such as Nevada, have only a single study. NV Pub. Util. Comm., Dkt 17-06014, NV Power Co. Rule 15 (April 11, 2018).)) that are designed to first assess the potential impacts of a project on the system and, if impacts are identified, to determine necessary upgrades and their costs.
In practice, Initial Review criteria are more conservative than Supplemental Review criteria, whereas detailed studies are designed to more closely simulate actual effects rather than approximating probable impacts through screening.
For the most part, the screens used in interconnection procedures today do not yet recognize whether a project has the capability to control and limit export.Each screen is designed to evaluate the risks of different types of distribution system impacts. How to modify a screen to accurately evaluate export-controlled projects varies based upon the impact the screen is assessing. Similarly, study processes also need to take into account a project’s export limiting capabilities for the power flow analyses to accurately identify potential system impacts. The following sections analyze how the screening and study processes should be altered to take into account export controlled projects. Where applicable, specific changes to interconnection rule language are recommended, using the FERC SGIP as a model. Recommendations for changes to today’s current interconnection procedures are described at the end of each section, and the end of this chapter includes a compilation of model language that can be inserted into a state’s interconnection procedures.