How to Apply for a Solar Interconnection Agreement
- Sarah Lozanova
- Aug 1
- 11 min read
Updated: Aug 4
Electricity has traditionally flowed one way—from centralized power plants to homes and businesses. But with the rise of distributed energy resources like residential and commercial solar systems, the grid now supports two-way power flow. This shift is made possible through the solar interconnection process.
To export excess solar energy to the grid, homeowners and businesses must complete a solar interconnection application and secure a utility-approved interconnection agreement for solar. This agreement confirms that the PV system meets all technical and safety standards required for grid connection and Permission to Operate (PTO).
As solar adoption grows, utilities have refined their solar interconnection process, creating clearer requirements and more predictable timelines. At GreenLancer, we support contractors by providing solar interconnection agreement services, including interconnection drawings and engineering support.
Here’s what you need to know about how solar interconnection works and how to keep your projects on track. Table of Contents
What is a Solar Interconnection Agreement?
A solar interconnection agreement allows homeowners to both draw electricity from the grid when their solar panels aren’t generating enough power and export excess energy back to the utility. This agreement is essential for participating in net metering, where eligible customers receive solar credits for surplus energy sent to the grid.
Why Is a Solar Interconnection Agreement Important?
PV interconnection is critical for homeowners who want to maximize financial benefits from their solar investment. Without solar interconnection approval, any excess electricity produced would go unused, preventing homeowners from earning solar credits on their utility bills. Many net metering programs allow these credits to roll over for up to a year, but some utilities compensate surplus energy at a lower wholesale rate rather than the retail rate. Since net metering rules vary by region, understanding your utility’s interconnection policies is essential.
Interconnection agreements for solar are vital for your clients to get the most value from the solar electric system, thus boosting the return on investment. If the solar power system doesn’t have batteries and isn’t connected to the power grid, homeowners get no benefit from the surplus solar power they produce.
For grid-tied solar systems without batteries, interconnection agreements for solar ensure homeowners can tap into the utility grid when needed, such as at night or during cloudy conditions. Off-grid solar systems do not require interconnection, but when the grid is accessible, maintaining a solar interconnection is often the most cost-effective solution.
Solar Interconnection Services by GreenLancer
GreenLancer provides expert solar interconnection agreement services, including interconnection drawings, permit-ready plan sets, and engineering reviews. Create a free account to streamline your solar interconnection process and get your clients to Permission to Operate status faster.
Step-by-Step Solar Interconnection Process
Applying for a solar interconnection agreement involves several key steps, typically handled by the solar installation company on behalf of the homeowner.
Step 1 - Submit a Solar Interconnection Application
The first step in securing an interconnection agreement for solar is submitting an interconnection application to the utility company. This application must include essential details about the PV system, such as system capacity, installation location, and technical specifications. Providing accurate data helps the utility assess grid compatibility and determine if any upgrades are necessary to support the new solar interconnection.
A complete solar interconnection application may also require electrical diagrams, equipment data sheets, and any necessary permits or certifications. The utility company will review these documents to ensure the system meets safety standards, regulatory requirements, and grid integration protocols. Approval of the solar interconnection agreement is essential for connecting the PV system to the grid and obtaining solar PTO.
Step 2: Secure Solar Permits for Interconnection
Securing the necessary solar permits is a critical step in the solar interconnection agreement process. After your solar interconnection application is approved, you must obtain the required solar permits from the local Authority Having Jurisdiction (AHJ) to ensure the system complies with safety standards and regulatory requirements.
Meeting solar permit requirements necessary for solar interconnection commonly requires the following:
Building and Electrical Codes Compliance: Grid-tied solar systems in the United States must comply with the National Electrical Code (NEC), building codes, and local AHJ requirements. NEC standards, which cover various aspects such as wiring methods, grounding, overcurrent protection, and equipment specifications, are updated periodically. It's critical to comply with the latest version, which is currently the 2023 NEC edition.
Structural and Electrical System Design: AHJs may request detailed structural and electrical system design plans for an interconnection agreement for solar to ensure the installation meets safety standards. Our solar design service can help with permit-ready solar plan sets with electrical diagrams.
Equipment and Solar Inverter Specifications: Authorities may require specifications for solar panels, inverters, and other components to ensure they meet performance and safety standards for solar interconnection.
Solar Site Plan and Location: AHJs may need a site plan showing the proposed location of the solar system to assess its compatibility with local zoning regulations and building codes.
Electrical Diagrams: These illustrate the PV system’s wiring, circuitry, and solar interconnection to the electrical grid. Detailed schematics help identify any potential safety concerns.
Structural Analysis and Wind Load Calculations: In some areas, AHJs may request structural analysis and wind load calculations to ensure the solar system can withstand local weather conditions. This is most common for ground mounts and commercial PV systems. The GreenLancer network includes licensed engineers who can complete these solar engineering requirements.
Solar Permit Application Fee: AHJs often require an application fee to cover administrative costs associated with reviewing and processing the PV permit application. The fees can vary widely by AHJ, system size, and solar system type.
Step 3: Pass the Solar Inspection for Interconnection
Following the installation of the solar array, authorized inspectors or relevant authorities inspect to verify that the solar project meets all safety and performance requirements. PV systems are inspected before obtaining an interconnection agreement for solar to ensure the installation complies with safety regulations and is correctly and safely installed.
The solar inspection will verify whether:
The solar system meets NEC and building code requirements and has structural integrity
The solar permit documents match the actual PV installation
There is proper labeling of system components, appropriate disconnects, and safety protocols
The PV system complies with solar interconnection requirements, including proper synchronization, anti-islanding measures, and voltage regulation
Step 4: Get Solar PTO (Permission to Operate)
Once the system passes inspection and meets all regulatory requirements, the utility company grants Permission to Operate, finalizing the solar interconnection agreement. PTO approval allows the solar system to begin generating electricity and exporting surplus power to the grid.
Solar PTO confirms that the system complies with safety and operational standards, enabling homeowners to benefit from net metering where available. It also ensures that the system can be monitored and maintained for long-term efficiency. Securing PTO is a key milestone in the interconnection agreement for solar, marking the official activation of the PV system and the start of solar energy savings.
Technical Requirements for Solar Interconnection
Connecting a solar system to the grid requires compliance with several technical and regulatory standards to ensure safety, reliability, and grid stability. These solar interconnection requirements govern how PV systems interact with the electrical grid.
Proper Synchronization
Solar systems must match the grid's frequency (typically 50 or 60 Hz) and voltage. This synchronization is critical to prevent damaging surges and ensure smooth power transfer. Inverters play a key role in adjusting the DC output of the panels to meet grid standards.
Anti-Islanding Protection
During a power outage, islanding occurs when a PV system continues supplying power to the grid, posing a risk to utility workers. Anti-islanding protection is required in all solar interconnection agreements to prevent backfeeding and automatically shut down solar generation when the grid goes offline. This function is built into modern inverters, using active and passive detection methods.
Voltage Regulation
To obtain an interconnection agreement for solar, PV systems must maintain voltage levels within the utility’s specified range (typically 110V or 240V for residential). Inverters dynamically adjust power output to prevent voltage fluctuations that could disrupt grid stability or damage electrical equipment.
Protection Systems
Grid-tied solar installations require overcurrent protection, ground fault detection, and rapid shutdown mechanisms. These safety features prevent electrical faults, overheating, or fires. Circuit breakers and inverters with integrated protection features help mitigate risks and ensure compliance with NEC standards.
Metering & Communication
A solar interconnection agreement typically requires a bi-directional utility meter, which records both energy consumption and excess generation sent to the grid. Many utilities install smart meters that enable real-time monitoring and data exchange, allowing homeowners to track solar production and net metering credits.
Interconnection Agreement for Solar
The interconnection agreement for solar outlines the technical, safety, and regulatory conditions for connecting a PV system to the grid. It includes inspection and certification requirements, ensuring that the system meets grid interconnection standards. Without an approved solar interconnection agreement, grid-tied solar systems cannot legally operate.
What’s Included in a Solar Interconnection Agreement?
A solar interconnection agreement outlines the technical, safety, and contractual conditions required to connect a solar energy system to the grid. This document ensures compliance with utility regulations and grid standards, detailing the responsibilities of both the system owner and the utility provider.
Technical Requirements
The interconnection agreement for solar specifies the necessary technical standards, including voltage synchronization, frequency matching, and power quality parameters. For example, inverters must comply with IEEE 1547 standards for grid interconnection, and UL 1741 certification ensures compatibility with utility grid-support functions.
Solar Interconnection Equipment Standards
The agreement details equipment requirements such as inverters, protective devices, and metering systems. Inverters must include low-voltage ride-through (LVRT) capabilities to maintain system stability during temporary grid disturbances. Bi-directional metering is often required to track both solar energy production and electricity drawn from the grid.
Safety Requirements for Solar Interconnection
Safety protocols ensure secure grid integration. Rapid shutdown systems (RSS) and anti-islanding protections prevent backfeeding during outages, protecting utility workers. Ground fault detection and compliance with National Electrical Code standards help prevent electrical hazards. Larger systems, such as commercial and utility-scale projects, may require protective relay systems to handle higher voltages.
Solar Interconnection and Metering Requirements
The agreement defines how solar energy is measured and credited. Many systems use advanced metering infrastructure (AMI) for real-time tracking. Depending on local policies, homeowners or businesses may receive compensation through net metering or feed-in tariffs, ensuring proper credit for excess energy exported to the grid.
Liability and Insurance in Interconnection Agreements
Liability clauses in solar interconnection agreements define responsibilities for system failures or damages. Larger solar projects often require substantial insurance coverage to mitigate risks associated with grid disruptions or equipment malfunctions. The insurance requirements may vary, but utility-scale solar installations typically have higher insurance premiums due to their potential impact on grid stability.
Fees Associated with Solar Interconnection
Connecting a solar system to the grid may involve costs for technical reviews, impact studies, and grid upgrades. Commercial and utility-scale projects often require an interconnection study to assess grid reliability and potential infrastructure upgrades. Some utilities may also charge ongoing fees for grid monitoring and communication infrastructure maintenance.
What Is a Solar Interconnection Study?
A solar interconnection study evaluates the impact of the system on grid stability, voltage regulation, and power quality. It involves load flow simulations, short-circuit analysis, and protective coordination to ensure compliance with IEEE standards. Large-scale systems may require additional grid impact studies to determine necessary upgrades before approval.
Solar Interconnection Timeline: How Long It Takes
The timeline for solar interconnection depends on the system size and the utility's approval process. In most cases, a properly completed interconnection agreement for solar allows systems to receive PTO within a few weeks, often in less than a month.
Delays in the solar interconnection process can occur if utility requirements are not met. Common issues include unfulfilled utility requests, system inspection delays, or the use of non-compliant equipment. While most applications move smoothly, some solar installers have encountered longer wait times due to utility meter issues or grid infrastructure constraints.
How Much Does the Solar Interconnection Process Cost?
The solar interconnection process can vary significantly based on the size and complexity of the system and the utility's requirements. Most residential systems with standard interconnection agreements receive Permission to Operate in under a month.
However, for larger commercial or utility solar installations, the interconnection agreement process may involve additional steps, such as impact studies to assess grid stability, which can lengthen the timeline. Technical delays can also occur due to equipment incompatibilities or failure to meet grid safety protocols, like anti-islanding measures or voltage regulation requirements. Utility inspections and transformer or meter upgrades might extend the solar interconnection agreement timeframe, particularly if special approvals are needed.
Why You Shouldn’t Activate a Solar System Without PTO
Turning on a solar system without receiving solar PTO could cause issues, as the utility company hasn’t authorized it. This could lead to fines or shutdown orders, especially if power backfeeds during a grid outage. Also, activating the system without solar PTO might void warranties or lead to insurance issues. It's best to wait for official solar PTO approval to avoid these complications and ensure compliance and safe operation.
Solar Interconnection for Systems with Battery Storage
PV systems with batteries can still qualify for solar interconnection. In fact, solar energy storage systems can allow your customers to take advantage of time-of-use rates if available through the local utility company.
Using TOU Rates with Solar Interconnection and Batteries
In some utility territories, the price per kWh of power varies by the time of day and even the time of year. This encourages customers to consume electricity during times of off-peak demand, thus smoothing out demand. If a solar system includes a battery, your customers have more flexibility in where the power originates (the grid vs. the battery).
They can draw power from the battery during times when rates are higher and from the grid when rates are lower. Therefore, batteries allow your customers to save even more on their power bills.
Recent Updates to the Solar Interconnection Process
The Federal Energy Regulatory Commission (FERC) has implemented significant reforms to modernize and accelerate the solar interconnection process. These changes are designed to reduce project backlogs, standardize the interconnection application workflow, and help developers secure interconnection agreements for solar more efficiently.
With faster approvals, more predictable timelines, and clearer technical requirements, these reforms support quicker access to Permission to Operate and broader adoption of clean energy.
FERC Order No. 2023: Reforming the Solar Interconnection Process
In July 2023, FERC issued Order No. 2023, a sweeping overhaul of how transmission providers manage solar interconnection applications. The goal was to address growing backlogs in interconnection queues, especially for distributed energy resources like residential and commercial solar.
Key changes introduced in Order 2023 include:
Cluster studies to evaluate multiple interconnection requests at once
Firm deadlines and penalties for delays
More transparency, including public heatmaps and cost estimates
Financial readiness requirements to discourage speculative applications
This order streamlined the solar interconnection process by setting clearer timelines and expectations for utilities and solar developers. It makes it easier to move from an interconnection application to PTO approval.
FERC Order No. 2023-A: Clarifying Interconnection Rules
FERC followed up with Order No. 2023-A in March 2024, which addressed 31 rehearing requests. This update clarified technical and procedural elements of the solar interconnection process, including:
Withdrawal penalties and cost responsibilities
Timelines for demonstrating financial readiness
Grid upgrade responsibilities and confidentiality terms
“Option to build” rules for network upgrades
Together, these orders enhance the consistency and enforceability of interconnection agreements for solar, while giving utilities the tools to better manage and process large volumes of distributed energy interconnection requests.
Transmission Planning Reforms Supporting Interconnection
In May 2024, FERC released Order No. 1920 and Order No. 1977, which support long-term transmission development and federal siting authority. These reforms don’t change the interconnection agreement directly but affect the broader infrastructure needed to support future solar interconnection capacity. Key elements include:
20-year regional transmission planning
Cost-sharing for multi-state transmission upgrades
Environmental justice and tribal engagement in permitting
Greater federal authority to site critical transmission lines when states deny approval
By expanding the grid’s capacity and reach, these orders help alleviate structural bottlenecks that have historically delayed solar interconnection agreements, especially for large-scale and utility-connected projects.
How FERC Reforms Affect Solar Interconnection Agreements
For solar installers and developers, these FERC reforms reduce uncertainty and shorten the timeline from interconnection application to PTO. By simplifying the steps needed to obtain an interconnection agreement for solar, the reforms support faster project delivery, lower soft costs, and more widespread access to net metering and energy export compensation.
Despite these improvements, solar interconnection queues remain long in some regions. However, as more transmission providers implement these new requirements, the solar interconnection process is expected to become faster and more transparent nationwide.
Why Solar Interconnection Agreements and PTO Matter
Although the PV interconnection and solar PTO process may seem daunting at first, it’ll get easier over time after you’ve navigated it once or twice. Depending on the utility company in question, the process may vary a bit, so there may be a learning curve when applying for grid interconnection with a different utility company. However, the benefits of receiving solar PTO are significant and enable your clients to get more value from their solar energy systems.
GreenLancer can expedite the solar interconnection agreement and permitting process with quality PV plan sets and our solar design services, so you can focus on what you do best. Know that GreenLancer’s partners will manage your interconnection application from start to finish. Complete the form below to learn more.
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