Mixing Different Wattage Solar Panels: Good Practice or Not?

Mixing Different Wattage Solar Panels

Solar power is one of the most popular forms of renewable energy. In order to attain the maximum benefits from the installation of solar energy, one has to understand the basic principles behind the concept of solar power.

The most asked question related to the power is whether mixing different wattage solar panels is possible. After addressing this question, we have come to various things which are shared in this article.

Guidelines For Mixing Different Wattage Solar Panels

Is Mixing Different Wattage Solar Panels Possible?

Let us understand the concept with the help of an example. Have you ever bought a 200-watt solar panel and wondered if it can be used with your old 100-watt panel? Then yes, you can mix solar panels that have different wattages. But it is not usually advised because mixing different wattage panels reduces the efficiency and power output.

Wattage Mixing Reduces Efficiency and Power

A variety of wattage panels has different voltage and amps outputs. The system always favours the lowest voltage or amp, which puts the larger panel on the back burner. This, as a result, reduces the overall efficiency and power output of your solar panel array.

From sailboat solar panel installation to residential panels, certain basic electrical rules apply. They can be used together. It is relevant to understand the technique of mixing the different wattage solar panels.

Wattage Mixing Determines the Wiring System

The wiring of the solar panel is connected either in series or parallel. Normally, you don’t have to pay attention to the details, but if you’re dealing with mismatched wattage, the wiring system that you choose becomes important.

As per the predetermined rule of formulae, the same voltage should be connected in parallel, whereas the same current should be connected in series.

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Series vs Parallel Connections

Wiring Mixing Solar Panels In Series

How to Connect Panels in Series

To connect solar panels in a series, all you need to do is connect the positive wire of each panel to the negative wire of the next and vice versa.

Advantages of Wiring in Series

Most of the residential solar panels are connected in series. When you connect solar panels in series, the voltage increases, but the current stays the same. You can get rid of smaller wiring and have a long run between the panel and the inverter without losing electricity.

The Disadvantage of Wiring in Series

The general disadvantage of connecting the wiring in a series is that if one panel is in the shade or goes out, the whole system gets less effective.

Different Wattage Solar Panels Wired in Series

If mixed-wattage solar panels are connected in series, the total voltages increase. On the other hand, the amps are reduced to the current of the lowest panel.

Wiring Mixing Solar Panels In Parallel

How to Connect Panels in Parallel

To connect solar panels in parallel, make the connection of all the positive wires together. Perform the same with the negative wires. Always make sure that you are using the right wires before connecting the panels.

The Advantage of Wiring in Parallel

When you connect solar panels in parallel, the amps or, we can say, current increases, but the voltage remains the same. This usually suits the greater battery charging needs of off-grid solar users.

Disadvantages of Wiring in Parallel

To handle the higher power of the current, a parallel setup requires a heavier wire. Along with this, more wire is required to make all the connections.

But if you’re confused about what size cable to use for a 12v solar panel, you can consult an expert.

Wiring Different Wattage Solar Panels in Parallel

If mixed-wattage solar panels are connected in parallel, the total current is increased, but the voltage of the system reduces to the voltage of the lowest panel.

Wiring Mixing Solar Panels In Parallel

A Combination of the Two

A combination of series and parallel circuits can also be used to avail the maximum benefits from the combination. With respect to this, primarily connect the solar panels in a series and then join the strings in parallel.

Make the installation of microinverters to optimize each solar panel individually. This avoids the problem of power loss due if one of the panels in the system is in the shade.

The Best Wiring for Mismatched Panels

The efficiency of the output of the voltages is reduced if you connect solar panels without matching either the amps or voltages. If your solar panels are not matched in size, the system will always choose the lowest value.

It is then important to connect the wires in the right manner. But whether wired in series or in parallel, it is applicable to both. Plugging in a solar panel with a lower power rating into your array will reduce the total energy output.

Mismatched Solar Panels In Series

Solar panels connected in series add to the voltage. The amps are not affected at all. But mismatched solar panels connected in series will choose the lowest amp among the solar panels.

Mismatched Solar Panels In Parallel

Solar panels connected in parallel help in increasing or adding the amps. The voltage remains unaffected, but mismatched solar panels connected in parallel reduce the power of generating the output of the solar panels.

If the Solar Panels Have Different Wattage

If the wiring of the different wattage solar panels are connected in parallel, if they have similar voltages, efficiency will reduce. If both the series and parallel connections are contained with a diode, it helps in preventing the current.

This diode allows the current to flow in a single direction. As an alternative way, one can make the installation of a microinverter.

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To Connect Two Solar Panels To One Battery

Connecting two solar panels to a single battery with a single charge controller is an easy process to perform.

First of all, all you need to do for the process is:

You cannot connect your solar panels directly to a battery.

The batteries may get damaged when you connect your solar panels directly to your battery (lead-acid or lithium). A device is required to measure the state of charge of your battery, and then it gets charged accordingly, just like a car battery charger.

The name of the device that is needed is the charge controller. The role of the charge controller is to control the charging of the battery.

  • Purpose of using a charge controller:
  • Prohibits charging when the battery is full.
  • Adjust the charging voltage and current.

What is the overall procedure for doing the same?

  • Step 1: Connect Your Battery to The Controller
  • Step 2: Connect Your Solar Panels Together
  • Step 3: Connect The Two Solar Panels To The Charge Controller
  • Step 4: Connect The Loads
How To Connect Two Solar Panels To One Battery

Can You Mix Different Brands Of Solar Panels?

Yes, the mixing of different brands of solar panels can be done. In case they meet the same specifications and watts, the task can be accomplished. Among most people, there is a misconception that we can’t mix different brands of panels, but after certain testing, it is found that it does work. But there are a few things that you should consider before taking action.

There is a big difference between amorphous solar panels and crystalline solar panels. The components of these types of solar panels are different on a fundamental level, so they cannot be mixed together or used in conjunction with each other. Voltage, amperage and wattage are key components of the panels.

Five Ways To Mix And Match Solar Panels

Mixing and matching solar panels can be very useful. For instance, a mixture of large and small panels might help you fit the most capacity onto a small roof. One can also make the inclusion of extra panels to an existing solar panel system. However, mixing and matching solar panels can cause various issues when not done in the right way. In the worst case, it can also cause damage to the whole system. However, it is possible to make different models of solar panels work together safely and effectively.

Here we have mentioned five ways to make the connections:

1: Use a Microinverter for Each Solar Panel

The use of the micro-inverter allows each solar panel to work independently. This simply states that the micro inverters can mix and match solar panels as per the requirement of the user. This is the ultimate solution for mixing and matching solar panels.

Micro inverters give you the freedom to mix and match solar panels altogether.

2: Use Power Optimizers

Power optimizers help each solar panel to work in a string at its own preferred voltage and current. These power optimizers work a lot for solar panels as they have the same number of cells (all 60-cell or all 72-cell). However, the datasheet must be checked thoroughly if you’re planning on mixing 60-cell solar panels with 72-cell solar panels in the same string.

Power optimizers allow the user or the owner to mix and match solar panels on the same inverter string.

3: Different Solar Panels on Different Strings

Many solar inverters allow the solar system to connect with two independent input “strings”. These independent strings allow you to use two different kinds of solar panels, one on each string. Apart from this, you could use two separate inverters.

4: Different-Sized Solar Panels with the Same Cells

Some manufacturers produce two different sizes of solar panels that are made up of the same cells. For example, they might be manufacturing both 60-cell and 72-cell versions of the same solar panel. Panels with different numbers of cells work fine together.

5: Solar Panels that are Similar to Enough

Did you know that no solar panels are the same, even if they belong to the same model? While it’s best to match solar panels in a string as close as possible, a very small difference between panels will lead to a very small difference in their power output. Sometimes, the differences are so minor that it doesn’t cause any problems. This makes it possible to mix solar panels from different manufacturers.

Conclusion

The objective of mixing the solar panel is to understand and use solar energy. Always remember that while solar energy is harnessed from the sun, any electrical installation must follow certain basic rules of both safety and efficiency.