How To Wire Solar Panels

How To Wire Solar Panels

The wiring of the solar panel is also known as stringing. Now the question arises of how to string solar panels together. This is a fundamental topic for any solar installer. It’s important to understand how different stringing impacts the voltage, current, and power of a solar array. The user of the solar panel requires an appropriate inverter for the array and needs to make sure that the system will function effectively.

It is considered that if the voltage of your array exceeds the inverter’s maximum, production will be limited by what the inverter can output. The production is totally dependent on the extent the inverter’s lifetime may be reduced. If the array voltage is too low for the inverter, the system will also produce less production of energy because the inverter will not operate until its “start voltage” has been reached.

Series vs. Parallel Stringing

There are multiple ways to approach solar panel wiring. One major way to understand the differences is by stringing solar panels in series versus stringing solar panels in parallel. These different kinds of stringing configurations have different effects on the electrical current and voltage in the circuit.

How To Wire Solar Panels In Series

Stringing solar panels in series is inclusive of connecting each panel to the next in a line.

Just like a typical battery, solar panels have positive and negative terminals. While connecting the stringing in series, the wire from the positive terminal of one solar panel is connected to the negative terminal of the next panel.

When stringing panels are interconnected in series, each additional panel adds to the total voltage (V) of the string, but the current (I) in the string remains the same.

One drawback to stringing in series is that a shaded panel can decrease the current through the entire string. The reason behind the same is the current remains the same through the entire string; the current is reduced to that of the panel with the lowest current.

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How To Wire Solar Panels In Parallel

Stringing solar panels in parallel is a bit complicated. Rather than connecting the positive terminal of one panel to the negative terminal of the next, when stringing in parallel, the positive terminals of all the panels on the string are connected to one wire, and the negative terminals are all connected to another wire.

In this situation, each additional panel increases the current (amperage) of the circuit. However, the voltage of the circuit remains the same, which is equivalent to the voltage of each panel. A benefit of stringing in parallel is that if one panel is heavily shaded, the rest of the panels can operate normally, and the current of the entire string will not be reduced.

How To Wire Solar Panels In Parallel

Tips For Wiring Solar Panels

Based upon the connectivity of the wires in accordance to the series or parallel, it’s reasonable for your solar energy clients to conclude that series wiring is best for installations that receive some shade – and parallel wiring is better suited when shading isn’t a problem.

There are some additional factors that are worth considering.

Make Sure Your Voltage Is within the range of the Inverter

Every inverter has its very own voltage range. For maximum power generation, it’s critical that the PV panels (and wiring) lie within each inverter’s spectrum:

•     If the array’s voltage falls below this range, the installation won’t generate any usable power. The reason behind the same is that the inverter doesn’t become operational until it achieves its “start” voltage. Your panels may be producing energy, but none of that energy is saving you money.

•     If the array’s voltage lies above this range, your panels will generate more power than what the inverter can accommodate. This indirectly decreases the power of saving money. Thus, it can also reduce the overall life of the inverter.

Know Your MPPTs

MPPTs stands for Maximum Power Point Tracking, which is a relatively modern type of inverter technology that can optimize PV output even as conditions change. It accomplishes this by monitoring the system to help the inverter find the optimal balance of voltage and current for “maximum” power generation.

Tracking this sweet spot in real-time allows inverters with MPPT technology that are installed to generate more clean energy than legacy inverters.

Use the Right Design Software to Plan Systems

The utilization of wiring configuration is totally dependent upon the PV system. The system involves crunching the numbers as you run through multiple solar power system designs for each potential project.

An emerging generation of solar design software is helpful in automating this process. After accomplishing the wiring recommendations, energy production calculations, monthly savings, and 3D renderings were all generated with a few mouse clicks. This software not only helps in saving time, but it can also move you closer to making that sale.

Key Electrical Terms to Know Before Wiring Solar Panels

Before understanding the connections of the solar panel, it is important to understand the key electrical terms:  These electronic terms use Voltage, power, and current.

Always keep in mind that all these three terms are connected with each other.

Let us have a deep knowledge of all the terms:

1. Voltage

Electromotive force or voltage is a term that is useful to define the charge difference between the two points in an electrical circuit.

One of the most relevant things that affect the voltage while connecting solar panels is the amount of sunlight falling on the panels. The more sunlight, the more voltage, and energy will be produced.

2. Electrical Current

Electrical current is the flow of charge that is named free electrons in the electrical circuit. It’s measured in amps (ampere).

3. Electric Power

One of the major ways to understand what electric power is by the medium of the mathematical formula:

P = V x I.

Where V stands for Voltage and I is Current.

So, to get the electric power, both voltage and current need to get multiplied.

In other simple words, power is the calculation of the rate at which the generated electric energy travels in a circuit.

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How To Connect Solar Panel Wire

The process is actually quite straightforward and much less complicated than assumed. The very first step is to determine which type of connection you are going to put together. The decision to connect the wire can be based on the voltage and amperage limitations of your power inverter. One must also consider the capabilities of your charge controller, as this will help in protecting any batteries you plan to charge with your solar panels.

Once you know which type of connection you would get the most out of your existing solar equipment, you can simply follow the instruction manual that is sent along with your solar panels. Essentially, the solar panels are connected like the terminals when you are boosting a car battery. If you are going for a series connection, simply use the solar cables that came with your solar panels to connect one panel’s positive terminal to the other panel’s negative terminal. One can opt for both sets of terminals, and you will have created the series. One can connect the panels to your power inverter and charge controller, which will then be connected to your battery bank.

To connect your solar panels in parallel, simply connect the positive terminal of one panel to the positive terminal of the next. Then do the same for the negative terminals. Once the panels are connected to your power inverter and solar charge controller, you are pretty much finished.

Connecting Solar Panels To House Wiring

1. String and Install Solar Panels

Before you can connect solar panels to your house’s electricity, make sure to install them on the roof of your home. There are a couple of ways to make the installation done, and it requires knowing the technique of installing the string solar panels together. One solar panel won't do a lot for your home, so it is necessary to have several panels installed and linked together.

2. Connect Solar Panels to the Inverter

Solar power is not the same as electricity in your home. Solar panels use direct current (DC) electricity, and your house uses alternating current (AC) electricity. These types of electrical currents are not compatible with each other unless you use a power inverter.

After the installation of the solar panels on your roof and stringing them together, the next step is to connect those panels to the inverter. One can also connect the inverter to a battery either before or after you've connected the inverter to the solar panels. Even though you're connecting the solar panels to your house, it's still a good idea to have a battery that can store the solar energy four times[a] when the panels may not be generating a lot of power. This way, one can keep using solar energy in your home at night and during times of the year when the weather is very cloudy.

3. Wire the Battery into Home Circuit Breaker Panel

The next thing that needs to happen is connecting the inverter to the home circuit breaker panel either directly or through the battery. Take the wires from the battery (or the inverter) and connect the wires to each circuit breaker. As you connect the wires to each circuit breaker, you'll be connecting solar power to each electrical zone of your home.

Solar energy can be useful in the home, but it's rarely enough to power everything all the time. Solar panels will minimize, but not always eliminate, the amount of power pulled from the power grid, so you need to maintain a connection with the grid.

The process is known as “net metering.” It is essential to make your electric meter move backward, crediting you for the power you’re contributing and charging you less each month. Sometimes this requires an extra meter to track the electricity you're contributing compared to the electricity you’re using, but it can help save you money on your electric bill.

4. Connect the Inverter to Fuse Box

Once everything is wired to the home circuit breaker panel, the inverter needs to be connected to the fuse box. This is what will allow the inverter to convert direct current (DC) to alternating current (AC) electricity.

Solar energy must support the electricity in your home. Solar energy is not always perfect, so it's a good idea to have backup power options, like generators, to pull from when solar power is not available.

Conclusion

Electrical wiring and the benefits of connecting solar panels in series vs. parallel will help the customers make better-informed decisions about their clean energy investments. In fact, being able to communicate ideas clearly (and visually) is essential to the solar sales process.