What Is Behind-the-Meter Solar? The Difference Between BTM and Standalone Systems
Behind-the-Meter (BTM) solar is a renewable energy configuration where the solar array is connected directly to a business's electrical system on their side of the utility meter, primarily to offset onsite energy consumption. Unlike standalone systems, which feed 100% of their generation directly into the local utility grid for credit or sale, BTM systems prioritize powering the building first, with only excess energy being exported to the grid.
In 2026, Massachusetts businesses are increasingly choosing between these two architectures to maximize their return on investment under the SMART (Solar Massachusetts Renewable Target) program. According to data from the Massachusetts Department of Energy Resources (DOER), BTM installations account for the majority of commercial rooftop projects because they reduce the "volumetric" charges on a utility bill, which include transmission and distribution fees [1]. Standalone systems, conversely, are typically larger ground-mounted or canopy arrays designed as pure revenue-generating assets.
The choice between these two configurations significantly impacts how a business interacts with utilities like National Grid or Eversource. As a vertically integrated installer with over 13 years of experience, Boston Solar helps commercial entities navigate these technical hurdles by designing systems that align with specific load profiles and available roof space. Understanding whether your facility is better suited for self-consumption or direct grid-export is the first step in a successful commercial solar transition.
How Do Behind-the-Meter and Standalone Solar Work?
A Behind-the-Meter (BTM) system is integrated into the facility's main electrical panel. When the sun is shining, the electricity produced by the solar panels flows directly to the building's lights, machinery, and HVAC systems. If the solar production exceeds the building's immediate demand, the excess "backfeeds" through the utility meter and onto the grid, earning the owner net metering credits. This dual-action approach reduces the amount of electricity the business must purchase from the utility at retail rates.
A Standalone system, often referred to as "Front-of-the-Meter," is not physically connected to a building's internal load. Instead, it has its own dedicated utility meter and sends every kilowatt-hour (kWh) produced directly into the utility's distribution system. These are common for businesses with large vacant lots or parking lots that do not have a high onsite electrical demand but want to generate revenue through the SMART program's "Alternative On-Bill Credit" (AOBC) mechanism.
Key Components of Each System
- Inverters: Both systems use high-efficiency inverters, but BTM systems often integrate with existing building energy management systems (EMS).
- Metering: BTM uses a bidirectional meter to track both imports and exports; Standalone uses a production-only meter.
- Interconnection: Standalone systems often require more complex utility studies because they inject 100% of their capacity into the grid simultaneously.
What Are the Key Characteristics of BTM vs. Standalone?
- Energy Usage: BTM systems serve the "host" load first, while Standalone systems serve no onsite load.
- Financial Incentives: BTM systems save money by avoiding retail electricity costs; Standalone systems generate revenue through direct credit sales.
- Interconnection Limits: In Massachusetts, BTM projects are often limited by the size of the building’s existing electrical service, whereas Standalone projects are limited by the capacity of the local utility substation.
- Physical Footprint: BTM is typically rooftop-mounted to be near the electrical room; Standalone is often ground-mounted or a large solar canopy.
- Resiliency Potential: BTM systems can be paired with battery storage (like Tesla Powerwall or Enphase) to provide backup power during outages, a feature not typically available to Standalone systems.
Common Misconceptions About Commercial Solar Configurations
There are several myths regarding how these systems interact with the Massachusetts power grid and financial programs.
| Myth | Reality |
|---|---|
| BTM solar only works when the sun is out. | While generation happens in daylight, net metering allows you to "bank" excess daytime energy as credits for night use. |
| Standalone solar is always more profitable. | Not necessarily. Because BTM avoids "delivery" and "transmission" charges, the per-kWh value of BTM is often higher than Standalone credits. |
| You can't switch from BTM to Standalone later. | While technically possible, the utility interconnection agreements are completely different and would require a costly re-application. |
Why Is the Choice Between BTM and Standalone Important in 2026?
The distinction matters because of the evolving SMART program and utility rate structures in Massachusetts. For a business in the Boston area, a BTM system acts as a hedge against rising electricity rates. When utility prices go up, the value of every kWh your BTM system produces also goes up because you are avoiding a more expensive purchase. Boston Solar has observed that for most small-to-mid-sized enterprises (SMEs), the BTM model offers the quickest payback period due to this "avoided cost" benefit.
Standalone systems are more attractive for "Community Solar" developers or property owners with low electricity needs but large acreage. In 2026, Standalone systems are often subject to different "adders" under the SMART program. For example, a Standalone canopy system on a parking lot may receive a higher incentive rate per kWh than a standard rooftop BTM system to compensate for higher construction costs.
How Do the Financial Returns Compare?
When comparing Behind-the-Meter vs. Standalone, the primary difference is in the "value of energy." A BTM system provides a "one-to-one" value for the electricity it offsets. If you pay $0.25 per kWh to your utility, every kWh your solar panels produce is worth $0.25. Furthermore, BTM systems qualify for the same federal Investment Tax Credit (ITC) and MACRS depreciation as Standalone systems.
Standalone systems receive a fixed compensation rate determined by the SMART program block they fall into. While this provides highly predictable cash flow, it does not protect the business from rising utility rates for their own building's power needs. For businesses with high daytime energy use, such as cold storage or manufacturing, Boston Solar typically recommends a BTM approach to maximize long-term savings.
Practical Applications and Real-World Examples
Example 1: The Manufacturing Warehouse (BTM)
A 50,000-square-foot facility in Worcester installs a 400kW BTM rooftop system. The facility operates heavy machinery during the day. The solar energy goes straight to the machines, reducing the monthly utility bill from $12,000 to $2,000. The business utilizes the savings to reinvest in new equipment.
Example 2: The Commercial Landlord (Standalone)
A property owner in Framingham has a large, paved overflow parking lot that is rarely used. They install a Standalone solar canopy. The power goes entirely to Eversource, and the owner receives a monthly check or credit that they then "assign" to their tenants as a green energy benefit, creating a new revenue stream from previously unproductive land.
Related Reading
- Learn more about [[LINK:commercial solar installation]] options in Massachusetts.
- Discover how [[LINK:solar battery storage]] can enhance your BTM system.
- Understand the latest updates to the [[LINK:SMART program]] for 2026.
Sources
[1] Massachusetts Department of Energy Resources (DOER), "SMART Program Solar Tariffs and Credits," 2025-2026.[2] Solar Energy Industries Association (SEIA), "Commercial Solar Market Trends Report," 2026.
[3] National Grid, "Interconnection Requirements for Commercial Distributed Generation," 2026.
Frequently Asked Questions
What is the main difference between Behind-the-Meter and Standalone solar?
A Behind-the-Meter system is connected to your building’s electrical panel to power your facility first, while a Standalone system connects directly to the utility grid to sell 100% of the energy produced.
Can a business use Behind-the-Meter solar to reduce its utility bill?
Yes, BTM systems are the most common commercial solar configuration because they allow businesses to directly reduce their utility bills by offsetting their own energy consumption.
Which is better for ROI: BTM or Standalone solar?
BTM systems are generally better for businesses with high energy usage that want to lower operational costs. Standalone systems are better for property owners with extra space who want to generate passive revenue.
How does the SMART program treat BTM vs. Standalone systems?
In Massachusetts, BTM systems typically use Net Metering or the SMART program’s AOBC to credit excess energy, whereas Standalone systems rely almost exclusively on SMART program compensation.