Wondering how to connect your solar system together? This guide breaks this complex process down into easy-to-follow steps. We’ll walk you through the connection of the core components of your solar system: solar panels, inverter, charge controller, and battery.
If you are not comfortable with electrical work, consult a qualified solar installer.
Homeowners normally don’t install solar panels themselves. A project of a PV system has to get approval from authorities before you can construct it. In many areas, only a certified solar installer can get a permit. If you want to learn how to choose a contractor, check out our article on 5 tips on picking a solar installer.
Grid-tie systems aren’t DIY-friendly in particular. Only a utility representative can connect a solar system to the grid and he has to verify that it is safe for the grid and complies with building and electrical codes in the area. We recommend DIY-installation only for home off-grid and mobile off-grid systems and only for those who have the necessary skills. Remember that with an off-grid system, you don’t need an electrical permit but still require a building or a land-use permit.
Let’s start with the heart of your system – your solar panels. There are two primary ways to connect them: in series and in parallel.
In a series connection, the positive terminal of one panel connects to the negative terminal of the next, and so on. The current remains constant throughout the circuit, while the voltage adds up. This is a great option for longer distances between panels and the inverter as higher voltage reduces power loss over long cable runs. Yet your system’s output is limited by the weakest panel in the series and a single faulty or shaded panel can disrupt the entire circuit.
In a parallel connection, you connect together all the positive positive terminals and then all the negative terminals. The voltage remains constant across each panel, while the current adds up. This method is better for shaded areas where some panels might underperform as individual panel failure won’t affect the entire system. Yet voltage drop can be an issue over long distances.
Combining series and parallel connections allows you to adjust the current and the voltage in your system to your preference. It can be useful when your inverter or controller has strict restrictions on maximum input voltage or current. It is more difficult than the standard configuration and requires an even number of panels.
In the end, the optimal connection method depends on your specific system design. For a small system with few panels as well as for longer cable runs, the series connection is the best. If your roof has shaded areas, the parallel connection would reduce power losses. Ensure your inverter’s voltage and current ratings are compatible with the chosen connection method.
Off-grid solar installations should always have a battery bank as a part of the system. Every time you add batteries to solar panels, wire a charge controller in between. It protects energy storage from the high voltage of a solar array and prevents overcharging and deep discharge. If your system doesn’t have a battery bank, proceed to connect solar panels to an inverter.
It's best to wire the controller to the battery before linking it with the solar panels. Many controllers undergo an initialization sequence upon connecting to a battery for the first time. If you connect the solar panel to the controller first, it might not initialize properly.
Charge controllers have designated terminals for battery connection. Follow the instructions in your controller’s manual. Connect the positive battery cable to the positive terminal of the charge controller and the negative cable to the negative terminal. Tighten the connections securely. Let the controller turn on if specified in the manual.
Cover solar panels when making connections so that you don’t work with active current.
Connect the positive and negative ends of the solar array to the charge controller terminals designated for solar input. Ensure all connections are firm. Consult your charge controller manual for programming options. You may be able to set charging parameters and monitor system performance.
In AC-coupled systems, the battery comes with its own inverter.
The inverter is connected either to your solar array or to your battery. Follow the instructions in the inverter manual. The idea largely remains the same: connect the positive and negative cables from your solar panels or battery bank to the designated DC input terminals on the inverter.
In a grid-tie system, only a certified electrician can connect your solar system to the grid. Usually, a utility sends an inspector who checks if the system complies with electrical codes and is safe to be connected to the grid. In an off-grid system, you decide to connect the inverter to an electrical panel of your house yourself. Small off-grid inverters have an AC socket and you can plug in any appliance or a power strip into it.
While DIY solar panel installation is a more cost-effective option, it requires careful planning, thorough research, and a commitment to safety. If you have the necessary skills and are comfortable working at heights and with electrical systems, then taking on this challenge can be a rewarding experience. But if you have any doubts or lack confidence, consulting with a licensed solar installer is the best course of action. They can ensure a professional installation that meets all safety standards and local regulations.
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Years of experience in translation and a love of nature help Julia find the right words to encourage going solar. She joined the team in 2023 and is happy to make her contribution to a greener future.
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Andrey had been a news editor and freelance writer for a number of medias before joining A1SolarStore team. Climate change and its impact on people's lives has always been among his interests and it partially explains his degree in Philosophy and Ethics.
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