In recent years, the use of solar energy in the US has been steadily increasing, with wired solar panels accounting for around 12% of all energy used in 2020.
You have a range of options when implementing a solar energy system. One of these options is how to wire the panels. There are different benefits to wiring solar panels in series vs. parallel, and knowing the advantages of each will help you make the best choice.
For a rundown of each method, keep reading.
The Difference Between Wiring Solar Panels in Series and Parallel
When comparing these two methods of wiring solar panels, the main difference is the output current and voltage.
With a series circuit, the output voltages add together while the current stays the same. When wired in parallel, the voltage will remain the same while the currents are added together.
Wiring solar panels in series
When you connect solar panels in series, it involves connecting the positive terminal of each panel to the negative terminal of the next. Each panel has a voltage and a current. At the end of the circuit, the output voltage will be larger, but the current won’t have changed.
For example, three panels in series with a voltage of 18V and a current of 6A would result in an output of 54V and 6A.
It’s also the best method if you need a low-amperage output. Smaller-gauge wires will save you money, but they can only handle a lower amperage.
When you’re on a budget, you may be wondering “How much can solar save“. A series circuit is one way to help keep costs down.
Wiring solar panels in parallel
To connect solar panels in parallel, you need to connect all of the positive terminals to each other, then repeat this for the negative terminals. With the same panels as above (3 panels at 18V/6A), the output would be 18V and 18A.
The main difference from a series setup is that this is ideal if any of the panels spend time in the shade. Each panel can act independently, which will help maintain the output. When one panel is blocked, it won’t affect the output of the other two.
This is also the best setup when you want to keep the voltage down. If you can match the output voltage from the panels to the charging voltage of your nominal battery, you can have a higher charging current without the need for voltage regulation.
Which is better?
Ultimately, when looking at wiring solar panels in series vs. parallel, there’s no definitive answer. The better choice varies from case to case, depending on the application and conditions.
A series setup is generally better when the panels won’t be shaded. These will perform better at the start and end of the day, as well as when there’s cloud cover. The high voltage means they’ll still be able to charge your batteries while running at lower efficiency.
If your solar panels are likely to experience a lot of shade, setting them up in series may not be very effective, so wiring them in parallel could be the best choice.
For more technology-related articles, check out some of our other blog posts.