Interconnection callout

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Interconnection

Looking to interconnect a generator, solar panels, or battery energy storage system to Central Maine Power's network? Learn more about the steps, requirements and resources needed for your project. Understand the different project categories and how the application process varies for each.

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Transmission and Distribution Interconnection Requirements for Generation (CMP schedule B) - “Blue Book”

 

We have two types of projects, FERC-jurisdictional and MPUC-jurisdictional generator interconnections. Both must follow the “ Blue Book ”. (Updated 05/15/2023)

 

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FERC jurisdictional projects

  • FERC regulates interstate transmission and wholesale electricity markets, including generator connections to the transmission system.
  • ISO New England (ISO-NE) manages the high-voltage transmission network and wholesale power markets in New England under FERC's rules.
  • Generators wanting to connect to the transmission system in New England must follow ISO-NE's Open Access Transmission Tariff (OATT) procedures.
  • All CMP transmission interconnection requests start with ISO-NE.
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MPUC jurisdictional projects

The MPUC manages projects where generators interconnect to the local distribution system and don't participate in wholesale electricity markets. To ensure a smooth process developers must follow the MPUC's guidelines for submitting an application, technical requirements, and interconnection agreements. To access the necessary forms and agreements, visit our accordion below.

Projects must follow the Rules of the Maine Public Utilities Commission, including:

  • Chapter 313: Customer Net Energy Billing (CNEB)
  • Chapter 324: Small Generator Interconnection Procedures
  • Chapter 328: Funding Source for Interconnection Ombudsman

Chapter 324 sets standards for connecting small renewable energy facilities to the grid, making the process efficient and promoting renewable energy.

 

Projects under Chapter 324 are divided into levels (1 through 4) based on their output capacity and technical requirements.

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Level 1

Typically residential solar projects, these are inverter-based generators of 25kW or less. This group has the simplest screening criteria to help facilitate a quicker interconnection.

Level 2

Typically commercial rooftop-solar or small solar sites, these are generators less than 2MW and are limited to $30,000 worth of Distribution System Upgrades.

Level 3

Non-exporting generators up to 10MW (do not qualify for Net Energy Billing).

Level 4

All generators not subject to FERC jurisdiction are reviewed under the Level 4 interconnection process, which includes a more comprehensive screening and study prior to interconnection.

Interconnection application resources

Interconnection application resources

Please review the process flowcharts for an overview of how applications are processed. The flowcharts detail customer actions, company actions, forms at each step.

Below are copies of the standard MPUC forms used for applications, interconnection agreements, and certificate of completion.

  • Pre-Application (Optional, ≥500kW)
    • $300 non-refundable
  • Ombudsman Fee
    • Effective as of December 11, 2024 the Maine Public Utilities Commission (MPUC), as seen within MPUC Chapter 328, has made it a requirement for the utilities to collect a $40.00 Interconnection Ombudsman Fee per application.
    • Level 1-4 = $40
  • Application Fees
    • Level 1 = $100
    • Level 2 = $100 + $2 per kW
    • Level 3 = $100 + $3 per kW
    • Level 4 = $3,000
  • Cost-Sharing
    • Level 1 = $150
    • Level 2 = $25/kW (On-Site-Load Customers, 25kW–250kW)
    • Level 3 = n/a
    • Level 4 = n/a

Below are the single-line diagrams depicting approved configurations for Chapter 324 projects with Generator-owned communications (set-ups other than residential smart-meters).

Level 2 Online Reports (application tracker): Shows Level 2 Projects that are above 25kW and the substation they applied at. Providing information to developer community on date application submitted, project status, facility capacity, fuel type.

Level 4 Public Queue (Chapter 324 Level 4 Public Queue): Published twice monthly to provide developer community information on queues at CMP substations. Provides information such as queue position, fuel type, circuit name, date application submitted, project status, facility capacity, study start and completion dates, IA signed date, 25% payment.

Summary Cost Sharing Projects by Substation: Provides a per-substation breakout of cost-shareable distribution upgrades such as Line Upgrades or TGFOV

Have questions about the MPUC Chapter 324 interconnection process? Send us an email and we will forward you an invitation for our next monthly Q&A session.

For additional information about the process, please contact us at  207-716-7920.

To apply for Customer Net Energy Billing in Maine, you need to fill out the required Chapter 313 Application. This is in addition to the Interconnection application. For more information on Maine Net Energy Billing (NEB) visit our page.

The "Distributed Generation Developers Guide: From Interconnection Application to Commission and Energization" is written by our DG project managers to answer developers' most frequently asked questions about the processes.

For CMP’s updates to the Transmission Cluster Studies, please see our September presentation.

For updates on CMP’s Transmission System Impact Studies, please see our latest biweekly report.

Have questions related to Reliability Committee (RC) Approval or i.3.9 Approval?

Submitting an interconnection application

Submitting an interconnection application

 

To begin your interconnection application, follow the steps below. Commercial customers submitting applications, please note you will be prompted to provide your Tax ID number.

 

  1. Please fill out New Service Request online form before submitting your portal application(s).
  2. For an overview of the CMP online application process, please see our Interconnection Online Application Portal (IOAP) Guide.
  3. To begin an application, please visit the CMP Interconnection Portal: Interconnection Online Application Portal (IOAP).

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Interconnection contact information

Have any questions about your application? Contact our team:

interconnection Presentations and workshops

Presentations and workshops

CMP will no longer include minimum loading on the circuit for Level 4 DG Thermal Analysis

 

Download our Minimum Loading - DG Level 2 Studies 7-16-2025 presentation

Guide to show developer community how to utilize CMP Hosting Capacity Map.