If you’re learning how solar panels work, understanding the technicalities between series vs parallel connections is a pretty advanced step in the research process – one that you may not necessarily need to take.
Although parallel vs. series wiring can be a large part of planning a DIY solar project, knowing your solar panel circuits is much less critical when working with a professional company like Palmetto that will handle the solar panel installation process from start to finish.
Even so, series vs. parallel conversations often arise in our homeowner consultations – and for a good reason – because how your solar panels are wired together ultimately affects your energy generation, savings, and overall project ROI.
To help you plan and prepare for your home’s new renewable energy system, we will outline everything you need to know about series vs parallel solar panel wiring.
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Background: Understanding Series and Parallel Circuits
Without getting too far into the weeds, technically speaking, the distinction between series and parallel solar panels is based on the differences between series and parallel circuits.
To quickly understand the difference between a series and parallel circuit, consider a string of holiday lights. If one bulb along the string of lights were to go out, the result would be much different depending on whether the lights were wired in series or parallel.
If the lights were wired in a series, one bulb’s outage would likely cause the rest of the lights on the string to go out as well. For this reason, most modern holiday decorations are wired in a parallel circuit so that one outage will not cause the rest of the lights on the string to go dark.
Solar Panels in Series or Parallel
A bit more complicated than holiday lights, but based on the same set of principles, solar panels can also be wired in a series or parallel circuit.
While each circuit type has pros and cons (which we’ll detail later), the goal of both series and parallel solar wiring is to allow the electricity generated by your solar panels to be sent to the rest of your energy system and ultimately into your home.
- Series Solar Panel Wiring: In a series, solar panels are more or less wired together in a chain, like a set of train cars connected together on a single track. Wiring solar panels in a series is like setting up a line of dominos designed to work together in one specific direction. However, this comes with the risk of potential stoppages if one component is not adequately performing its function.
- Parallel Solar Panel Wiring: Parallel, meaning “side by side,” solar wiring is more like multiple train cars running on separate tracks, in which one car’s speed will not affect another. Likewise, suppose your home’s electricity supply is a river. In that case, parallel wiring is a bit like adding a new tributary with every solar panel rather than trying to send more water down the same singular channel.
Which is better: series or parallel solar panels?
In reality, there is no “better way” to connect solar panels, as both series and parallel connections have different effects, which come with benefits and drawbacks. At a high level, here is an introductory look at the pros and cons of series vs. parallel:
| Effect | Pros | Cons | |
|---|---|---|---|
| Series | Each additional panel increases system voltage; amperage remains the same | Lower wiring and equipment costs, easiest to set up in a DIY installation | Shaded or broken panels affect the performance of neighboring panels |
| Parallel | Each additional panel increases system amperage; voltage remains the same | Improved reliability with independently operating solar panels | Increased wiring and equipment costs |
While series wiring is the simplest and cheapest way to connect solar panels, solar panels wired in parallel can help prevent potential adverse chain reactions from underperforming panels.
In the same vein, series connections are ideal for chains of panels (also known as solar arrays) that all constantly deliver roughly the same amount of solar power output at any given moment. In contrast, parallel connections are better when your panels generate different amounts of electricity.
As such, series connections work best for panels installed on the same roof face with full sunlight exposure, and parallel circuits are better for panels that are partially shaded throughout the day or on surfaces facing different directions.
Learn more: Are solar panels suitable for your roof?
Are residential solar panels wired in series or parallel?
Typically, most home solar panel systems are wired with a combination of series connections and parallel connections.
While there are pros and cons of utilizing exclusively series or parallel wiring in small, DIY solar energy systems, whole home systems often need both types of connections to achieve the critical balance of voltage and amperage necessary to efficiently produce solar power and send it through the rest of your inverter system.
Note: To maximize each solar panel’s individual production, solar energy systems that use microinverters are always wired in a parallel connection.
Solar Panel Wiring: Series vs Parallel
In summary, choosing between series and parallel wiring for your home solar panels is a decision that should ultimately be made by a professional based on the unique characteristics of your property and the components in your renewable energy system.
While it never hurts to have a breadth of technical knowledge in your back pocket while looking at your solar options, series vs. parallel wiring is another step of the solar installation process best achieved when an expert can develop a solution specifically for your home.
For questions about your home’s solar potential, speak with a Palmetto solar advisor today or discover your savings by designing your solar energy system.
