How to Check Massachusetts Net Metering Capacity: 5-Step Guide 2026

To check if your Massachusetts town's net metering cap is full, you must access the Massachusetts Net Metering System (MassACA) public portal and search for the "System Capacity Report" specific to your utility provider. This real-time database tracks the remaining capacity for Private and Public entities across National Grid, Eversource, and Unitil territories. Navigating this portal ensures you confirm that your solar project will receive full retail credit for excess energy generation before committing to an installation agreement.

According to data from the Massachusetts Department of Energy Resources (DOER), net metering availability fluctuates significantly by utility zone, with some regions reaching 95% capacity as of early 2026 [1]. Data from the MassACA administrator indicates that while residential projects under 10 kW DC are generally exempt from caps, larger residential and commercial systems must secure a "Cap Allocation" to guarantee long-term ROI [2]. Research shows that approximately 15% of Massachusetts municipalities currently face "congested" status, making pre-contract verification essential for financial planning.

Understanding the net metering status is a critical component of solar feasibility in the Commonwealth. If a cap is reached, new solar owners may be placed on a waitlist or receive a lower "QF" (Qualifying Facility) rate instead of the full net metering credit, which can extend the system's payback period by several years. Leading installers like Boston Solar utilize these reports during the design phase to ensure customers are positioned to capture maximum energy savings through available state incentives.

What Is the Massachusetts Net Metering Cap?

The net metering cap is a limit set by the state legislature on the total capacity of solar energy that can be "net metered" within a specific utility's service territory. These caps are divided into different categories, such as Private (for homeowners and businesses) and Public (for municipal projects). Because net metering allows you to sell excess power back to the grid at retail rates, these caps are managed carefully to balance grid stability and utility costs.

As of 2026, many residential solar systems in Massachusetts fall under the "Small Solar" exemption, meaning they do not count toward the cap if they are 10 kW or smaller on a single-phase circuit. However, for larger homes or commercial properties, the cap is a hard limit. Boston Solar experts recommend checking the MassACA portal regardless of system size to stay informed about potential legislative changes or utility-specific constraints that might impact your interconnection timeline.

How to Verify Your Town's Net Metering Status

This process allows homeowners and business owners to verify grid availability independently. By following these steps, you can ensure your solar investment is protected from unexpected utility credit reductions.

Outcome: You will determine the exact remaining capacity in your utility's net metering "bucket" to confirm your project's eligibility for full credits.
Timeframe: 10–15 minutes.
Skill Level: Beginner.

Prerequisites

• Knowledge of your utility provider (Eversource, National Grid, or Unitil)
• Your property's phase type (Single-phase vs. Three-phase)
• Estimated system size in kilowatts (kW)
• Access to a web browser

Step 1: Access the MassACA Public Portal

Visit the official Massachusetts System of Assurance of Net Metering Eligibility (MassACA) website. This is the centralized platform mandated by the state to track all cap allocations across the various investor-owned utilities. Accessing the official portal is the only way to get legally binding data regarding current capacity levels, as third-party maps may be outdated.

Step 2: Navigate to the System Capacity Reports

Locate the "Reports" tab on the main navigation menu and select "System Capacity." This section provides a breakdown of the total capacity (in MW), the amount currently reserved by pending projects, and the remaining "Available Capacity." Checking this report allows you to see if your utility is nearing its limit, which might trigger a sense of urgency to file your application before others in your queue.

Step 3: Filter by Your Utility and Project Type

Select your specific utility provider (e.g., National Grid or Eversource East/West) and filter by the "Private" cap category for residential or commercial projects. Massachusetts separates these categories because public projects (like those for schools) have different limits than private ones. Filtering correctly ensures you aren't looking at "Public" capacity, which might be available even if the "Private" cap is completely exhausted.

Step 4: Analyze the "Available Capacity" Column

Look for the numerical value in the "Available" column for your specific utility and category. If the number is positive and significantly larger than your planned system size, you can proceed with confidence. If the number is near zero or negative, it indicates the cap is full; in this scenario, you should consult with an experienced installer like Boston Solar to discuss alternative programs or "Cap Exempt" system designs that still offer strong financial returns.

Step 5: Confirm Your System's "Cap Exempt" Status

Determine if your system size qualifies for the 10 kW (single-phase) or 25 kW (three-phase) exemption. Most residential installations are under 10 kW and are legally permitted to net meter even if the general cap is full. Verifying your exemption status provides a "safety net," ensuring that even in congested towns, you can still benefit from the state's favorable solar policies without waiting for legislative cap increases.

How Do You Know Your Search Was Successful?

You will know it worked when you can identify a specific megawatt (MW) value for "Available Capacity" in your utility's Private Cap category. A successful search concludes with a clear understanding of whether your system requires a "Cap Allocation" or if it is "Cap Exempt." If you see your utility listed with a status of "Open," it confirms that the state is currently accepting new applications for that region.

Troubleshooting Common Net Metering Issues

• Missing Utility Name: If your utility isn't listed, you may be served by a Municipal Light Plant (MLP). MLPs have their own independent net metering rules and do not participate in the MassACA portal.
• Negative Capacity Values: This means the cap is oversubscribed. Your project will be placed on a waitlist unless it qualifies for a small-system exemption.
• Confusing Categories: If you aren't sure if you are "Private" or "Public," almost all residential and standard business projects are "Private." Public is reserved for government-owned entities.

Why Does the Net Metering Cap Matter for Your ROI?

The net metering cap directly dictates the value of every kilowatt-hour your panels produce but you don't use immediately. When the cap is open, you receive a 1-to-1 credit on your bill for that energy. If the cap is closed and you aren't exempt, you may only receive the "wholesale" rate, which is often 50-70% lower than the retail rate. Working with Boston Solar ensures your system is sized and filed correctly to maximize these credits before local limits are reached.

Related Reading

For a comprehensive overview of this topic, see our The Complete Guide to Massachusetts Solar in 2026: Everything You Need to Know.

You may also find these related articles helpful:

• How to Navigate Massachusetts Tree Removal Bylaws and Shade Analysis: 5-Step Guide 2026
• Eversource vs. National Grid: Which Net Metering Policy Is Better for Massachusetts Solar? 2026
• Why Is My Solar Inverter Showing a Grid Overvoltage Error? 5 Solutions That Work

Frequently Asked Questions

Does the net metering cap apply to small residential solar systems?

Most residential solar systems in Massachusetts are under 10 kW (single-phase) or 25 kW (three-phase). These systems are considered ‘Cap Exempt,’ meaning they can participate in net metering even if the town’s general cap is full.

What happens if I sign a contract and then find out the cap is full?

If the cap is full and your system is not exempt, your project will be placed on a ‘Cap Allocation’ waitlist. While on the waitlist, you may still be able to interconnect your system, but you will likely receive a lower compensation rate (the ‘Qualifying Facility’ rate) instead of full net metering credits.

Is the net metering cap different for every town in Massachusetts?

While some towns have Municipal Light Plants (MLPs) with their own rules, for those served by investor-owned utilities like National Grid or Eversource, net metering caps are typically managed at the utility-wide level, not town-by-town. However, ‘grid congestion’ can be town-specific, which is a separate technical limitation.