Maryland Cost Allocation Method and Commercial Solar Planning
For Maryland businesses considering commercial solar, the point where a system connects to the electric grid can influence project design, schedule, and financial planning. The Maryland Cost Allocation Method, commonly called MCAM, changes how certain distribution-system upgrade costs are shared among customers seeking to interconnect solar and other distributed energy resources.
MCAM is not a single statewide price for connecting solar. The applicable charge depends on the serving utility, connection voltage, system size, feeder conditions, available hosting capacity, and the utility tariff in effect when the project moves through interconnection. That makes MCAM less useful as a stand-alone cost estimate and more important as an early planning consideration.
For a commercial property owner, the practical question is not only, “What is the MCAM fee?” It is, “How should our site, system design, and interconnection strategy account for the local grid before major project decisions are made?”
What Is the Maryland Cost Allocation Method
The Maryland Cost Allocation Method is a framework for sharing certain hosting-capacity upgrade costs among eligible interconnection customers. Hosting capacity is the amount of additional generation that a portion of the distribution system can accommodate without requiring infrastructure upgrades.
Before MCAM, a project that triggered an upgrade could face responsibility for the full upgrade even when the new grid capacity might later benefit other projects. MCAM was developed to allocate qualifying costs more broadly among interconnection customers and to reduce the “first project pays for everything” problem.
Maryland’s rules distinguish between projects connecting at primary voltage and those connecting at secondary voltage. For primary-voltage projects, the framework uses locational pricing intended to reflect how constrained a particular area of the grid is. Secondary-voltage upgrade costs are accumulated and shared through separate residential and commercial fee structures. Some projects are exempt from MCAM and remain subject to other interconnection-cost rules.
Why MCAM Matters for Commercial Solar Projects
MCAM can make certain interconnection costs more predictable, but it does not make interconnection uniform. Two similarly sized commercial solar projects may receive different results because they are served by different utilities, connect at different voltages, or sit on feeders with different amounts of available capacity.
A commercial solar budget should therefore treat interconnection as a site-specific workstream. Early estimates may change as the utility completes its screening and studies, confirms the point of interconnection, identifies direct-connection work, and applies the current tariff.
MCAM also does not replace other project costs. A project may still be responsible for equipment or work that directly serves the property, along with application, study, metering, engineering, permitting, or administrative charges. The details depend on the project and the serving utility.
The Most Important Variable May Be Where the Project Connects
For primary-voltage interconnections, Maryland’s framework is designed to send a locational signal. Areas with more available hosting capacity may be treated differently from areas where the distribution system is more constrained.
This means the electrical location of a project can matter alongside roof area, solar exposure, and energy use. A large, unobstructed roof is valuable, but it does not by itself confirm that the nearby distribution system can accept the proposed export without additional study or upgrades.
For businesses comparing multiple facilities—or developers evaluating several candidate sites—hosting-capacity and interconnection screening can help determine where deeper engineering work should begin. It may also reveal whether a different point of interconnection or a revised project configuration deserves consideration.
Five Questions to Ask Early in Project Development
Which Utility Serves the Property
Each utility implements MCAM through its own approved tariff. The serving utility determines the applicable process, tariff language, fee structure, study requirements, and available interconnection information. Utility territory should be confirmed at the beginning of project development rather than assumed from the mailing address.
Will the System Connect at Primary or Secondary Voltage
Connection voltage affects how the MCAM framework applies. Commercial buildings can have different service configurations, so the answer should come from electrical records and engineering review—not from building size alone.
How Much Hosting Capacity Is Available
Maryland utilities provide hosting-capacity information and, for eligible projects above the applicable threshold, a pre-application report may offer useful early data about the closest electrical facilities and available capacity. These tools are valuable for screening, but they are not a substitute for the utility’s formal interconnection review.
What Portion of the System Will Export to the Grid
A system’s nameplate capacity and expected export are related but not always identical. Load profile, operating strategy, energy storage, controls, and limited-export options can affect how a project interacts with the grid. Maryland rules allow utilities to consider certain flexible interconnection approaches when the required controls and operating limits can be documented.
Which Costs Fall Outside MCAM
MCAM focuses on qualifying hosting-capacity costs. Project-specific facilities, direct-connection work, studies, metering, service changes, protection equipment, and other requirements may be handled separately. A useful proposal should distinguish estimated MCAM-related charges from other utility and construction costs whenever that information is available.
How Engineering Can Improve Interconnection Planning
The lowest-risk approach is to integrate interconnection planning with system design. Treating the utility application as an administrative task after the solar layout is finished can create rework if the proposed system does not align with site electrical conditions or feeder constraints.
An engineering-led commercial solar team can evaluate several practical options:
- Right-size the array around the property’s energy use and business objectives
- Compare alternative points of interconnection when the site configuration allows
- Evaluate rooftop, carport, ground-mount, or combined layouts in relation to electrical infrastructure
- Consider export controls or limited-export operation where technically and economically appropriate
- Coordinate utility studies with structural, civil, electrical, permitting, and construction planning
- Update financial modeling as interconnection information becomes more certain
These steps do not guarantee a particular utility outcome. They help the project team identify constraints earlier, compare alternatives with better information, and avoid treating interconnection as a last-minute unknown.
What Maryland Businesses Should Expect During Interconnection
The interconnection process develops in stages. Early hosting-capacity data and a pre-application report can support screening. The formal application establishes the proposed system and its place in the utility’s review process. Depending on system characteristics and review level, the utility may perform feasibility, impact, or facilities studies before issuing an interconnection agreement.
During this process, a commercial customer should expect assumptions to become more specific. The point of interconnection, connection voltage, system size, export profile, protection requirements, upgrade scope, and applicable tariff treatment all affect the final picture.
Project schedules should leave room for utility review, customer decisions, design revisions, and construction coordination. A strong EPC partner should explain what is known, what remains preliminary, and which utility milestones may change the budget or timeline.
How Aurora Energy Approaches Maryland Commercial Solar
Aurora Energy develops and installs commercial solar systems across Maryland, Washington DC, and Northern Virginia. For Maryland projects, our process brings utility interconnection into the same planning conversation as engineering, procurement, permitting, construction, commissioning, and long-term performance.
That coordinated approach is especially important under MCAM. The objective is not to chase a universal fee estimate. It is to understand the specific property, serving utility, electrical configuration, available grid capacity, and operating goals early enough to make informed design and investment decisions.
MCAM may improve how shared grid-upgrade costs are allocated, but every commercial solar project still requires site-specific review. Current utility tariffs and formal study results should guide the final scope, schedule, and financial model.
