Each day, more than 646,000 Maine homes and businesses count on Central Maine Power Company (CMP) to efficiently deliver safe, reliable electricity from a supplier of their choice over our dependable infrastructure.
Many of our customers now are signing up with renewable energy generators as their source of energy supply.
Renewable energy incentives passed by the Maine State Legislature in 2019 have led to a surge of hundreds of new solar and other distributed generation (DG) projects statewide. CMP is committed to helping the State of Maine reach its renewable energy goals by working to connect small and large generators to our energy delivery system.
CMP’s role is to interconnect renewable energy generators quickly, cost-effectively and safely by following a process established by the Maine Public Utilities Commission (PUC). CMP has a dedicated team of engineers, project managers, construction workers and others focusing solely on distribution generation projects and interconnections.
Here are answers to questions you may have about CMP’s role in distributed generation projects.
Distributed generation (DG) is power produced by renewable energy sources such as solar, wind, hydro, and biomass near the point of interconnection to the energy grid or where the power will be used. DG facilities connect to distribution lines that lead to substations and not onto the transmission line system as traditional power generators do.
Community generation (CG) is electricity produced by a renewable energy company such as solar, wind, hydro, or biomass at a site that is supported by residential and/or non-residential customers through participation or subscriptions in exchange for credits on their utility bills. Each "community” solar array is designed by the developer to generate a specific amount of power, typically between 2 to 5 megawatts of electricity.
While most forms of community generation exist in Maine, community solar is likely best known because of developers’ interests in the state’s incentive program and the ability to market subscription plans to customers.
A community solar project (sometimes called "farm,” "garden,” or "array”) is developed or sited by a renewable energy developer and is supported by residential and non-residential customers who subscribe to or participate in a portion of the project in exchange for credits on their utility bills. Under one type of subscription program, the enrolled customer earns credits for their portion of the power generated on the solar array. The customer pays the business an agreed-upon rate for the credits and the credits will be applied to their utility bill which is delivered by CMP. The subscription option can be an alternative for people who cannot place solar panels on their own properties.
No. CMP is an electricity distribution company. We work with renewable energy generators to interconnect their facilities to our electrical system and distribute the electricity to homes and businesses.
CMP is not affiliated with any independent renewable energy generator. However, customers who subscribe to a community solar project within CMP’s service area will see their solar credits applied to the monthly bill they receive from CMP.
Yes. If you live in CMP’s service territory and receive your electricity through CMP’s transmission and distribution system, the community solar project(s) you subscribe to must also be in CMP’s service area. The community solar business may have offices located in different parts of the country, but the enrollment plan they are offering must have a community solar project in CMP’s service territory.
CMP is responsible to deliver electricity to your home or business over its energy grid. The electricity produced by renewable energy sources contributes to meeting the State of Maine’s goals to have a specified percentage of renewable energy shared over the state’s electricity power systems.
CMP cannot help customers decide whether to sign up for solar, other renewable energy offerings or any source of supply. All customers (residential, commercial, and industrial) should consult with individual generators and explore their options to determine what is best for them. For additional information, the Maine PUC website has a list of companies registered in Maine.
No. CMP does not make recommendations for community solar businesses.
Community solar businesses must register with the Maine Public Utilities Commission. You can verify a company’s registration information on this PUC site: https://apps.web.maine.gov/online/aeviewer/ME/9/list.html
Your local town or municipal office should be able to tell you what company is developing a solar array in your community so that you can access information about the company on the PUC’s website.
The renewable energy developer is required to get all necessary local, state and/or federal permits for its project. If a project requires a distribution line upgrade or extension to safely connect to our grid, CMP will pursue any local, state, and/or federal permits that may be needed.
No. Many community solar businesses offer programs that allow customers to subscribe to secure an allocated portion of power generated at their solar array. The customer pays the solar business an agreed-upon rate for the credits and those credits will be applied to their CMP utility bill.
Yes. Solar electricity is distributed through CMP’s energy infrastructure. An outage due to storms or other factors such as car accidents could affect electricity delivery to your home.
CMP is not affiliated with any solar businesses and will not approach landowners to lease their land for a solar project.
To facilitate the interconnection of a renewable energy project to CMP’s energy system, a developer may need to extend or upgrade a distribution line. Property easements are obtained by the solar generator for the placement and maintenance of the line if it crosses private property, ensuring appropriate distance on each side of the line for property access in order to perform maintenance or repairs due to an emergency.
The renewable energy developer is required to get all necessary local, state and/or federal permits for its project. If a project requires a distribution line upgrade or extension to safely connect to our grid, the developer or CMP will pursue any local, state, and/or federal permits that may be needed.
For distribution line upgrades or extensions, the distributed or community generator will secure the property needed for CMP to do the line work.
Occasionally a planned power outrage may be scheduled as part of the interconnection of the distributed generation facility to CMP’s energy grid. CMP will reach out to neighbors if one needs to be scheduled.
For years, CMP has worked with distributed generators to connect their renewable energy systems to our grid. Since late 2019, CMP has received hundreds of applications for interconnections from dozens of solar developers. Most of these are "community solar” projects that will generate between 2 MW (megawatts) and 5 MW of electricity.
CMP has a dedicated team of engineers, project managers, construction workers and others focusing solely on distribution generation projects and interconnections.
Once we receive an interconnection application from a solar generator, it goes through a multi-faceted application/system phase review and a design/build phase. More about what these phases are and how they are implemented is listed in the MPUC’s Chapter 324 rules and on CMP’s website under Interconnection.
Depending on the generator’s specific interconnection level, applications may need to be reviewed by the ISO-New England, the New England Power Pool (NEPOOL), or other agencies. CMP does not control these processes or timelines.
After the review process, the generator and CMP will reach an Interconnection Agreement which governs the connection of the generating facility to CMP’s energy grid, as well as the ongoing operation of the facility after it is connected to the system.
The Maine Legislature and the Maine Public Utilities Commission have established rules, regulations, and procedures regarding Maine’s electricity industry (Rule 65) including renewable energy generation and its interconnection to utilities’ electricity power system, such as CMP’s. Chapter 324 under Rule 65 sets statewide standards for the interconnection of small renewable energy facilities to a transmission and distribution (T&D) utility’s electrical system. The PUC has links to all chapters affiliated with distributed generation at https://www.maine.gov/mpuc/legislative/rules/part3-electric.shtml
To learn more about interconnecting to CMP’s electrical system, visit CMP’s Interconnection section on our website.
Among the many resources on the Interconnection page is CMP’s Schedule B – Transmission & Distribution Interconnection Requirements for Generation, which also is known as "The Blue Book.” This document is a guide that reflects, in part, CMP’s view of Prudent Electrical Practices with respect to the installation of generation interconnection equipment. These requirements are written to establish a basis for maintaining power quality, system reliability and a safe environment for the general public, power consumers, maintenance personnel, and equipment.
CMP’s primary obligation is to ensure reliable, safe power delivery to all customers. Each interconnection application is reviewed to determine whether the interconnection will require system modifications, or distribution system or substation upgrades. Numerous project design, system impact, cluster and other studies are undertaken during the process.
For generators who want to interconnect to CMP’s grid, the Maine Public Utilities Commission Chapter 313 rule establishes the terms and requirements under which regulated utilities within the state must implement net energy billing.
Community power generators will need to fill out the required Chapter 313 application in addition to the interconnection application, in order to apply for Customer Net Energy Billing.
Generators interested in learning more about the net energy billing process may visit CMP’s Net Billing section. There's a Frequently Asked Questions (FAQ) document at the bottom of the page.
CMP conducts monthly question-and-answer webinars for community solar generators who want more information about the Maine PUC Chapter 324 interconnection process. Virtual meetings are held the third Tuesday of every month and begin with a short presentation on the interconnection process followed by a 45-minute Q&A session. For more information or to sign up, email us at [email protected].