Solar

Solar electricity is a clean and renewable resource that can provide a variety of benefits to the electrical grid. Solar installed behind-the-meter, such as on a homeowner’s rooftop, lowers load on the distribution system and can offset the building’s energy bill, while larger utility-scale solar farms provide clean power to the grid throughout the course of the day. When paired with energy storage, solar can continue to provide clean, renewable power even after the sun sets. Learn more about solar technologies from the U.S. Department of Energy’s Solar Energy Technologies Office.

Solar photovoltaic (PV) panels can be installed in arrays ranging from small, residential rooftop installations that power a home to many acres of solar farm that can power entire towns – thousands of homes, businesses, schools, and other buildings.

Chart showing growth in installed solar capacity (MW) in Maine
Installed solar capacity in Maine. Data provided by ISO New England, Central Maine Power, Versant Power, and other sources.

Distributed generation

In Maine, distributed generation resources are renewable generators less than 5 megawatts (MW). Distributed solar interconnects to the distribution grid, and can provide a variety of benefits to both the entity where electricity is generated – residences, businesses, or other institutions – as well as to the overall electrical grid. Solar photovoltaic (PV) modules are the most commonly adopted generation distributed generation in Maine, although other generation sources including small-scale wind turbines, biomass systems, and hydroelectric are also included. Read more about solar and distributed energy resources from the U.S. Department of Energy Solar Energy Technologies Office.


State Policy

Maine has established in law a specific goal of “ensuring that solar electricity generation, along with electricity generation from other renewable energy technologies, meaningfully contributes to the generation capacity of the State…” (Maine Solar Energy Act, Title 35-A MRS § 3474).

Governor Mills at podium

In 2019, Governor Mills signed legislation that took significant steps to support the deployment of solar and other distributed generation in Maine. These included:

sun dog solar maine sport outfitters
Rockport Solar on Maine Sport Outfitters from Sundog Solar

Public Law 2019, Chapter 478 (LD 1711 An Act To Promote Solar Energy Projects and Distributed Generation Resources in Maine) included the establishment of two net energy billing (NEB) programs. The act also made changes to Maine’s overall NEB rules, including lifting the capacity cap on distributed generation resources eligible for NEB from 660 kW to 5 MW and removing any limit on the number of accounts or meters that can be associated with an eligible NEB project. Read more about the NEB programs below.

Other legislation that contributes to the deployment of solar:

Public Law 2019, Chapter 477 (LD 1494 An Act To Reform Maine’s Renewable Portfolio Standard) increased the share of Maine’s electricity that must come from renewable resources, known as a Renewable Portfolio Standard (RPS), to 80% by 2030 and set a goal of 100% by 2050. The two rounds of procurement conducted by the Maine PUC to meet this standard resulted in 24 renewable energy contracts, including 20 for solar projects.

Learn more about the RPS here, and see the Maine PUC’s announcements of the first and second procurement results for details.

Public Law 2019, Chapter 298 (LD 1181 An Act To Reduce Electricity Costs through Nonwires Alternatives) established the position of nonwires alternatives coordinator within the Office of the Public Advocate. The coordinator is responsible for reviewing certain proposed transmission and distribution projects and identifying whether alternatives, which could include deployment of solar in some cases, could more cost-effectively meet the system need. See the Office of the Public Advocate’s annual report for details.

Public Law 2019, Chapter 16 (LD 91 An Act To Eliminate Gross Metering) eliminated gross metering and reinstated net metering, or net energy billing. Gross metering required all electricity generated by rooftop PV systems be metered, even if it was being consumed on-site. In contrast, net metering is more supportive of rooftop solar and other distributed generation resources, providing a one-to-one credit for electricity generation sent to the grid without the need to meter generation consumed on-site.


Programs

If you are interested in participating in Maine’s solar/DER programs, there are resources for customers and developers below.

Net Energy Billing

Net energy billing provides bill credits for excess generation from distributed generation resources that is not consumed on site, but instead provided to the grid. NEB is available for residential, commercial, and industrial customers. These programs can provide energy savings by lowering overall utility bills and offer the opportunity to support renewable energy generation at a local level.

NEB participants may enroll solar generation they own themselves, such as rooftop panels, or may choose to join a solar array shared with other customers and located elsewhere in their utility’s service territory. This arrangement is commonly referred to as “community solar.” Community solar developers are required to provide information about the costs and benefits of their project to prospective customers.

There are two programs for NEB:

kWh credit program

This program is available to all electric utility customers. Through the kWh credit program, NEB participants receive a credit for every kWh provided to the grid from their solar array. These credits can be used to offset future charges on a one-to-one basis during billing periods when the participant uses more energy than their solar array generates. Any unused credits expire after 12 months.

Tariff rate program

This program is available to non-residential electric utility customers. Through the tariff rate program, NEB participants receive dollar credits at a rate determined annually by the Maine Public Utilities Commission (PUC). These bill credits cannot cause a customer’s utility bill to decrease below $0 in any given billing period, and any unused credits expire after 12 months.

Learn more on the Maine PUC “Net Energy Billing” webpage.

Maine's Office of the Public Advocate offers more information specifically to help electricity customers make informed choices about community solar projects.


Resources

The following resources are not GEO references, but may serve as useful tools for others seeking to gain additional information. 

Resources for solar customers

For general information and frequently asked questions about solar energy, see resources for consumers provided by the U.S. Department of Energy Solar Energy Technologies Office.

I want to learn more about installing solar at my home or business

Numerous solar installers operate throughout the state. As with any purchase of goods and services, consumers should consider practices including acquiring quotes from multiple installers and requesting references before signing a contract with an installer.

Residential solar installations are eligible for the federal renewable energy tax credit, which allows homeowners to deduct:

- 26% of the system cost if installed before January 1, 2023

- 22% of the system cost if installed before January 1, 2024

For more information, see this information provided by the ENERGY STAR program.

Customers of Maine’s two investor-owned utilities can find additional information about DERs from their utility below:

Central Maine Power customers

Versant Power customers

I want to learn more about community solar - I've been told I could get a discount on my electric bill

Additional information for consumers considering community solar is provided by the Maine Office of the Public Advocate.

All community solar providers are required to register with the Maine PUC, and must disclose any enforcement actions taken against them in Maine or other jurisdictions. Click here for the list of registered community solar providers maintained by the Maine PUC.

I need assistance resolving a dispute with my utility related to net energy billing

The Maine PUC has established a net energy billing rapid response process to resolve potential disputes about net energy billing issues. For more information or to initiate the process, contact the Maine PUC.

I want to know what happens to solar farms at the end of their life

Solar power projects occupying three or more acres are required to file a decommissioning plan with the Maine Department of Environmental Protection (DEP). The project owners must also provide financial assurance, such as a bond, sufficient to cover the cost of decommissioning the project as outlined in the plan approved by Maine DEP. If the solar project changes ownership, the new owners must inform DEP. For more information from Maine DEP, click here.

I want to learn more about solar on my farm

The Maine Department of Agriculture, Conservation and Forestry has issued a fact sheet regarding dual-use or agrivoltaic solar installations.

Resources for solar industry

Rules promulgated by the Maine PUC governing topics such as net energy billing and small generation interconnection procedures can be found here. The Commission also facilitates a monthly interconnection stakeholder call scheduled through docket 2020-00004.

The Maine Department of Environmental Protection administers certain applicable permitting requirements, as well as Maine's solar decommissioning law.

Certain state agencies have issued guidance for solar development:

The Maine Department of Agriculture, Conservation, and Forestry has issued technical guidance for utility-scale solar installation and development on agricultural, forested, and natural lands. The Maine Department of Inland Fisheries and Wildlife has issued solar project guidance and recommendations.

Information is available from Maine’s two investor-owned utilities regarding interconnection and other pertinent topics: