Sarah Lozanova
Solar Interconnection: Connecting Residential Projects To The Power Grid

Traditionally, power on the utility grid flows from power plants to customers. By design, however, the grid is equipped to receive small amounts of power from distributed generation systems, like small solar and wind energy installations.
As alternative energy systems gain popularity, homeowners are increasingly feeding renewable energy to the grid. Allowing the power to flow from customers requires utility interconnection with the electric company. In order to receive permission for this, certain steps must be completed.
Interconnection agreements allow homeowners to pull power from the power lines when their solar panels aren’t producing enough energy. Utility interconnection also enables many customers to take advantage of net metering (when applicable) with the power company and receive credits for surplus power they supply to the electrical grid.
As photovoltaic solar power systems become more widespread, utility companies are gaining experience in approving interconnection requests. In most areas, that results in a smoother process.
Why Is Solar Interconnection Important?
Utility interconnection is necessary for solar homeowners to take advantage of net metering and receive compensation for the power they supply to the grid. Net metering credits often expire after 1 year and often require a specific type of electric meter. Without utility interconnection, surplus electricity would not result in solar credits on electric bills. Keep in mind that net metering is not available in all utility territories and customers are sometimes compensated at a wholesale rate instead of a retail rate for surplus electricity.
Interconnection is vital for your clients getting 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.
Solar interconnection isn’t necessary for off-grid solar power systems. To have electricity around the clock, off-grid systems require an energy storage system. When the grid is nearby, it’s advantageous for most solar homeowners to be connect to it with a grid-tied solar power system. This arrangement allows homeowners to draw power when the solar power system isn’t producing enough power, such as at night or in cloudy weather. Conversely, off-grid systems need the capacity to meet the energy needs of the home 24/7, unless there’s also a backup generator on hand.
What Is The Solar Interconnection Process?
Applying for interconnection has two primary steps: applying for interconnection and receiving permission to operate (PTO). It’s critical to follow a specific order in the process to gain approval.
Applying For Interconnection
Utility companies need to ensure the solar power system meets electrical safety standards and net energy metering requirements to access the electric grid. Application forms for utility interconnection typically contain basic details about the property, electricity usage and the proposed solar PV system. Often, this will involve providing detailed information about the system, including the equipment, location, capacity and energy production estimates. In addition, utility companies often charge a fee, which varies depending on the solar PV system size, location and electric utility.
Receiving Permission To Operate
In order to receive permission to operate (PTO), the solar system must first be installed and pass local inspection, which may require showing the electrical panel and inverter to an inspector. The home will need a power meter with the capacity to track the electricity the home supplies to the grid. Sometimes, the utility company will need to install an additional meter or upgrade the existing one.
Once approved, the utility will issue permission to operate documentation. Now, you can officially turn on the solar power system and your client will receive compensation for the green power they supply. It’s not recommended to turn on a solar power system, except perhaps to test the equipment, until receiving permission to operate.
What Happens If You Turn On A Solar Installation Without Permission To Operate?
Turning on the solar energy system without a PTO can result in issues. Basically, it involves connecting to the grid without permission to do so. The utility company could issue a fine, and it could also degrade your relationship as a solar installer with them. If your solar client doesn’t have a meter that can differentiate between power they are supplying to the grid, they could actually be charged for this power instead of receiving credits. Therefore, our team recommends waiting until the PTO is issued before turning on the system.
Timeline: How Long Does Interconnection Take?
The length of the interconnection varies depending on the size of the solar array and the utility company. Most interconnection requests that meet utility requirements receive the PTO in less than a month.
The process can get slowed down by not facilitating utility company requests, such as making the system available for inspection. Also, using incompatible equipment can slow or halt the process. Some solar installation companies have experienced long delays with the utility company, but this issue is relatively rare and is sometimes due to issues with the utility meter.
Interconnection For Solar Arrays With Storage
Solar power systems with batteries can still qualify for utility interconnection. These systems can allow your customers to take advantage of time-of-use billing, if available through the local utility company.
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 where rates are higher and from the grid when rates are lower. Therefore, batteries allow your customers to save even more on their power bills.
Conclusion
Although utility interconnection may seem daunting at first, it’ll get easier over time after you’ve navigated the process once or twice. The process may vary a bit depending on the utility company in question, so there may continue to be a bit of a learning curve when applying for grid interconnection with a different company. The benefits of receiving permission to operate are significant and enable your clients to get more value from their solar energy system.
GreenLancer can expedite the utility interconnection application process so you can focus on what you do best. Have confidence knowing that GreenLancer’s partners will manage your interconnection application from start to finish.