You’ve taken the leap and decided to go solar. With solar panels and a solar power system, it’s time to start harvesting some rays. But do you know how to connect your solar panels for optimal energy capture?
You have two options for connecting solar panels: in series or parallel wiring. Before you can start reaping the massive benefits of solar power, you’ll need to figure out which system setup is better for your energy demands.
Don’t stress! Once you understand how to wire your solar panels, you’ll be well on your way.
Wiring Solar Panels—The Basics
When wiring your solar panels, there are two key metrics to be aware of: voltage and amps. Any given solar power system will have a minimum and maximum capacity for both. These limits influence how best to connect your panels together.
Different solar panels have different voltages and amps. That means you’ll need to connect them to your balance of system in a way that maximises the input without surpassing the maximum capacity of the power station or solar generator.
Typically, you’d connect multiple solar panels to one power station. How you connect the panels to each other and the balance of system can affect your solar power array’s effectiveness at capturing and storing energy.
Solar panels, on their own, are relatively useless. It’s when you connect them to a solar generator or balance of system to convert and store electricity that the magic begins. Therefore, it’s crucial to understand the basics of wiring to get the most out of your solar power system.
Solar Panels in Series vs Parallel. What Is the Difference?
You can wire your solar panels in two ways: in series or parallel. Each technique offers distinct benefits and may better suit different equipment and environments. We’ll break each down step-by-step to help you identify which option is right for you.
When you wire your system in series, you connect the panels one by one in a row. With this configuration, the system’s voltage is the total of all the panels. For example, if you have four panels with a voltage of 12 volts (V) each, you will multiply 12 by 4 for a total of 48V. With series wiring, the amps remain the same.
If you plan to wire your system in series, you can limit the number of panels you need by investing in high-voltage panels. For example, EcoFlow’s 400W Rigid Solar Panel has a high open circuit voltage of 37.10V, meaning you can capture over 74V with only two panels.
Solar panels wired in parallel create a ‘string’ of solar panels. You do this by connecting all the individual panels’ positive terminals and all the negative terminals.
From there, the two groups connect to your power station. In parallel wiring, the voltage stays consistent, but the amps are combined!
The Pros and Cons
The pros and cons of series and parallel connections come down to what you want from your system in terms of output, conversion efficiency, energy demands, and more.
Pros of Series Connections
- Higher voltage means a higher power output, allowing you to charge your solar batteries faster and store power for later.
- No need for hefty cables and components due to the low overall amperage
- Great for unshaded areas
Cons of Series Connections
- An obstruction or poor performance in one panel means they all perform poorly.
Pros of Parallel Connections
- The performance of one panel is not dependent on the others.
- Great for smaller, low-voltage systems, like on an RV
- Great for mixed light environments or occasional shade
Cons of Parallel Connections
- Requires thick, hefty cables and components that can withstand high amperage
Solar Panel Shading
Solar energy relies on access to sunshine. That means that shade can decrease the overall efficiency of your home solar system.
While sunshine is a renewable, abundant resource, not everywhere receives the same light. Certain parts of the United States are notoriously cloudy, while in others, the sun sets as early as 4:00 PM during the colder months. All of these factors can influence the amount of direct sunlight that reaches your solar panel, which, in turn, affects the amount of solar energy you capture.
And while you can’t control the amount of sun you get in your region, you can try your best to prevent any other shade from covering your panels. Try to arrange them in a place with no obstructions, such as on a rooftop away from tall trees.
However, if you have no other option, you can wire your equipment to maximise efficiency. If some of your panels are under shade from time to time, it’s best to wire them in parallel. This connection setup allows each panel to operate independently of the others, so you can continue soaking up sunshine even in some areas hidden by shade. With parallel connections, you’ll still reap the maximum benefits of panels that aren’t obstructed.
Besides the connection, it’s worth looking into solar panels that offer higher conversion efficiency even with shade and obstructions. Options, like the EcoFlow 220W bifacial solar panel, perform exceptionally well in low-light conditions, thanks to the double-sided panels that soak up ambient light.
Can’t decide which wiring method is best for you? You may find a hybrid setup ideal for your situation. A hybrid wiring method gives you the benefits of both series and parallel wiring. To start, wire multiple strings of solar panels together in series. Then, you can connect the multiple strings in parallel.
With this method, you increase the voltage of your setup when you wire panels together in series. Then, by connecting multiple strings of series-wired panels in parallel, you add the amperage values of each string together.
Essentially, when you opt for a hybrid setup, you can successfully enhance both the voltage and amperage in a way that you can’t when you wire in series or parallel alone.
Low Irradiance and Voltage Drop
Even the best solar generators can’t thrive without the proper environmental conditions. That’s why keeping your panels out of the shade and clear of obstructions (like snow) as much as possible is essential. If you are dealing with low irradiance, i.e., low light conditions, it could cause the voltage of your equipment to drop. And when it drops to a certain level, you may not be able to generate power at all.
All batteries or portable power stations require a minimum voltage to charge. The whole system is relatively useless when the panels fail to meet that minimum voltage.
Parallel-wired systems often run the risk of voltage drop. The reason is that the voltage is relatively low, to begin with, since the amperage increases, not the voltage, as you connect panels in parallel. Therefore, if conditions aren’t ideal, like in a low irradiance situation, you may swiftly be dealing with voltage drops. A hybrid or series wiring system could help solve this issue.
Additionally, you must minimise any risk of shading or low irradiance. Keeping the surface of your panels clean can also make a difference here! If shade or tree cover is unavoidable, it may be better to invest in portable solar panels rather than ones that require roof installation.
Voltage & Amps of Solar Panels Wired Series vs. Parallel
To understand how voltage and amperage function in solar panels, it’s first helpful to identify the difference between volts and amps. These are two common electrical terms you probably hear all the time but may need help understanding what they mean.
Voltage is a measure of electric potential or force. Ampere is a unit of electric current. A simple way to think about the relationship between the two is that voltage is water pressure that pushes water through a pipe, and amperage is the rate of flow of water moving through that pipe.
When you wire in series, you add up the voltage of all of your panels. That means the overall volts increase while the amps remain that of the panel with the lowest amperage. Keeping with the water in a pipe example, you increase the potential pressure but not the actual water flow rate.
On the flip side, when you wire in parallel, the amps add up, but the voltage does not. It means that you’ve increased the flow rate but not the pressure.
When deciding if you’re going to wire in series or parallel, it’s essential to pay attention to the voltage and amperage of all panels and the requirements and limits of your balance of system, such as your inverter, solar battery, and charge controller.
This way, you can identify the best way to wire your equipment to maximise power generation without surpassing the maximum that your solar power system can handle.
Wiring Solar Panels When Using a String Inverter
There are a few primary types of solar inverters that you’ll encounter: string, micro, and central. When wiring for a string inverter, you connect several solar panels in series. As we’ve discussed, the total voltage will be relatively high with series wiring while the current remains somewhat low. That’s where a string inverter can come in handy.
String inverters tolerate a high voltage and can handle many solar panels at once, making them an excellent low-cost investment compared to other types of inverters. Typically, you’ll only need one string inverter to handle all of your panels!
However, using a string converter and wiring in series can cause problems if you don’t have consistent access to unobstructed sunlight. A string of series-wired panels is only as strong as the weakest link. Therefore any shade or damage that affects one of the panels drives down the efficacy of the whole array.
Additionally, you should be wary of the risks associated with string inverter setups. Because of the high voltage achieved when wiring in series, severe electrical issues, like fire or arc-faulting, are more likely.
With solar energy costs rapidly decreasing, renewable energy technology is becoming more accessible to everyone.
This is excellent news for those who care about the climate crisis and want more autonomy over their residential power!
To get the most bang for your buck, you need to understand how to wire your solar panels effectively. While both parallel and series wiring methods offer perks and have drawbacks, either option can get you one step closer to being in control of your home’s power.
Frequently Asked Questions
We know solar panel wiring can be tricky, and we’re here to help. Here are some of the most common questions, explained.
Which wiring works better—series or parallel?
There is not one specific type of wiring that is ‘better’ than the other across the board. However, you may find that one style of wiring works better for your specific solar energy system. Different factors come into play here. For example, solar panels wired in parallel operate independently of one another. They’re best suited for partial light situations or when some of your panels may be under shade for part of the day. Alternatively, series wiring is better for sunny, open spaces where nothing will obstruct access to sunlight.
Can I wire solar panels in series and parallel?
Yes, you can wire solar panels in series or parallel. In some cases, you can even wire solar panels in both series and parallel simultaneously. For example, if you have two panels with 12V each, wire them in series to start. Then, assuming you have another 24V panel, you can wire them together in parallel. Assess your solar situation and how much sunlight you can access, then choose which wiring method will fit your needs the best.
Can I mix solar panels from different manufacturers with different electrical ratings?
The short answer is yes. Not all solar panels need to be identical to wire them effectively. However, different electrical ratings may make calculating your voltage and amps trickier. You need to be intentional about how you’re wiring to get the most out of your energy system.
If you’re wiring in series, all your panels should have the same current rating. Otherwise, the current output will only equal the lowest rating in the series. Similarly, parallel wired systems should have consistent voltage. If not, the system output will match only the lowest output rating.
If you connect solar panels from different manufacturers, compatibility is the main thing to check for. Products like the EcoFlow flexible solar panels come with universal compatibility, allowing you to create your solar set-up with existing and upgraded components.
Can you mix 12V and 24V solar panels?
While technically, it is possible to mix 12V and 24V solar panels, it is not ideal. When using panels with mixed electrical ratings, it’s best to opt for panels with specs that are as similar as possible. If you must use equipment with mixed power ratings, wire two 12V panels together in series before wiring them in parallel to their 24V counterpart. It’s always best to choose the wiring technique that makes the most sense for the specs of your equipment.
Does wattage increase in series?
When you connect equipment in series, you can increase the wattage of your solar energy generator. That’s because wattage = volts x amps. When you wire in series, you add the voltage of the individual pieces of equipment, thereby increasing the overall wattage.
Can you add more solar panels to your existing system?
Yes! Creating a comprehensive home energy system from the get-go helps ensure you select the best components for your needs. However, this may not always be possible. You may not have the funds to invest in all the necessary equipment upfront. It’s also common for people to underestimate their power needs, so they choose to expand their system later on. If you think it’s likely that you’ll want to add to your system as time passes, opt for an oversized inverter to accommodate future energy capture.
Can 12V solar panels be connected in series?
Totally! If you have more than one 12V panel, you can connect them in series to increase their overall voltage. Remember, when you wire in series, you add the voltage of each panel together. That means that if you have two 12V panels, you would have a total voltage of 24V. If you had 3, you’d have a total of 36V.
Do solar panels charge faster in series or parallel?
There is no clear-cut answer to whether series or parallel wiring can charge your battery faster. That’s because myriad factors influence charging speed. For example, if you wire in parallel, the voltage is typically lower than when you wire in series. With parallel wiring, your panels must perform at a higher consistency to maintain the minimum voltage required. That means that, generally, wiring in series could mean quicker charging times.
How can I wire multiple solar panels?
When wiring multiple pieces together, it’s essential to consider the individual electrical specs of each panel to inform your choice. You can wire in series, parallel, or even a combination of both to achieve optimal results. Remember, when you wire in series, you add the voltages together. When you wire in parallel, you add the amps. It makes sense to wire pairs of panels together in series, then wire those pairs together in parallel.