Maryland PSC COMAR 20.50.10.01: Solar Net Metering Guide

Key Takeaways

• Maryland's net metering rule, COMAR 20.50.10.01, applies to utilities including BGE, Pepco, Delmarva Power, and Potomac Edison (August 2026).
• Solar electric generating systems cannot exceed 2 megawatts in rated capacity (August 2026).
• Proposed systems must not exceed 200 percent of a customer's baseline annual electricity usage (August 2026).
• A statewide cap of 1,500 megawatts exists for all eligible customer-generators (August 2026).

What are the key provisions of Maryland's Net Metering Rule?

Maryland's Public Service Commission (PSC) sets the rules for net energy metering through COMAR 20.50.10.01. This regulation, titled "Md. Code Regs. 20.50.10.01 - General," applies to electric companies and customer-generators across the state. It falls under "Title 20 - PUBLIC SERVICE COMMISSION Subtitle 50 - SERVICE SUPPLIED BY ELECTRIC COMPANIES," ensuring that utilities like BGE, Pepco, Delmarva Power, and Potomac Edison provide net metering services.

The rule mandates that "An electric company shall provide net metering of electric service to eligible customer-generators using a meter capable of net energy metering." This provision ensures that customers who generate their own electricity can send excess power back to the grid and receive credit for it.

The core provisions of COMAR 20.50.10.01 define eligibility, system sizing, and overall program limits. These are critical for anyone planning a solar installation in Maryland.

| Commission Authority Header | "Title 20 - PUBLIC SERVICE COMMISSION Subtitle 50 - SERVICE SUPPLIED BY ELECTRIC COMPANIES" | Figures as of August 2026.

How does Maryland define an eligible system?

To qualify for net metering under COMAR 20.50.10.01, your electric generating system must meet specific size criteria. The regulation states that a system cannot be "operating an electric generating system that has a rated capacity of more than 2 megawatts." This means the maximum rated capacity for most solar installations eligible for net metering is 2 megawatts (August 2026).

A separate, lower limit applies to micro combined heat and power (micro-CHP) systems. For these, the regulation specifies that a system cannot be "operating a micro combined heat and power electric generating system that has a rated capacity of more than 30 kilowatts." Therefore, micro-CHP systems are limited to a maximum rated capacity of 30 kilowatts (August 2026).

Beyond capacity, the system's proposed output must align with your historical electricity consumption. The rule dictates that a "proposed electric generating system may not exceed 200 percent of the eligible customer-generator's baseline annual usage." This means your system's expected generation cannot be more than 200 percent of your past year's electricity use (August 2026). This sizing standard helps ensure that net metering primarily supports self-consumption and offsets, rather than large-scale energy production for profit.

What is the statewide net metering capacity cap?

Maryland's net metering program operates under a statewide capacity limit. The regulation specifies that net metering will continue "until the rated generating capacity of all eligible customer-generators in the State reaches 1,500 megawatts." This means there is a total cap of 1,500 megawatts (August 2026) for all net-metered systems across Maryland. Once this cap is reached, the terms of net metering for new installations may change. This statewide limit is a key factor for the long-term availability and structure of the program.

How does interconnection relate to net metering in Maryland?

Net metering eligibility in Maryland is directly tied to interconnection requirements. COMAR 20.50.10.01 states that "An eligible customer-generator shall comply with the provisions of COMAR 20.50.09." This means that before you can participate in net metering, your system must first meet the interconnection standards outlined in COMAR 20.50.09.

COMAR 20.50.09 covers the technical and procedural aspects of connecting distributed generation systems to the utility grid. It addresses safety, reliability, and operational standards. You can find more detailed information on these requirements in our guide: Maryland PSC Level 1 COMAR 20.50.09.09 Interconnection Guide. Understanding both regulations is crucial for a successful solar project in Maryland.

Can net metering eligibility change over time?

Yes, net metering eligibility in Maryland can be re-evaluated, particularly if you upgrade your electric generating system. The regulation includes a "System Upgrade Re-evaluation Rule," stating that "an electric company shall re-evaluate the baseline annual usage to determine whether the electric generating system continues to meet the requirements." This means that if you expand or modify your solar installation, the utility has the right to check if your system still complies with the sizing standards, such as the 200 percent baseline annual usage limit (August 2026).

Furthermore, the regulation includes a "Discontinuation Authority." It specifies that "If the eligible customer-generator's upgraded electric generating system does not meet the requirements of §D(1)(b) of this regulation, an electric company may discontinue net energy metering." This provision underscores the importance of adhering to the sizing and capacity limits even after initial installation. Any significant changes to your system should be reviewed against the current COMAR 20.50.10.01 requirements to avoid potential discontinuation of net metering benefits.

How we verified this information

We verified the information presented in this guide by directly accessing the official Maryland Code of Regulations. Our data is sourced from "Md. Code Regs. 20.50.10.01 - General" as published on Cornell Law School's Legal Information Institute website. We accessed this source on August 23, 2026, to ensure the accuracy and currency of the regulatory details provided.

Understanding Maryland's Net Metering for Your Project

Navigating Maryland's net metering regulations is a critical step for any solar energy project. The Maryland Public Service Commission's COMAR 20.50.10.01 outlines the framework for how you can connect your system to the grid and receive credit for excess generation. Key considerations include the 2 megawatt (August 2026) capacity limit for most systems, the 30 kilowatt (August 2026) limit for micro-CHP, and the requirement that your system not exceed 200 percent of your baseline annual electricity usage (August 2026).

Additionally, be aware of the statewide 1,500 megawatt (August 2026) cap on net metering, which could impact future program availability. Always ensure your project complies with both net metering and interconnection rules. For detailed interconnection guidelines, refer to our Maryland PSC Level 1 COMAR 20.50.09.09 Interconnection Guide. If you are planning a system, we recommend using a solar sizing tool to estimate your needs accurately and consulting the full text of the regulation.