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Connecting Solar Panels Together for Increased Power Article 30/06/2022
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Connecting Solar Panels Together

How to Connect Solar Panels Together

solar powerConnecting solar panels together is a simple and effective way of increasing your solar power capabilities. Going green is a great idea, and as the sun is our ultimate power source, it makes sense to utilize this energy to power our homes. As solar power becomes more accessible, more and more homeowners are buying photovoltaic solar panels.

However, these photovoltaic solar panels can be very costly so buying them over time helps to spread the cost. But the problem then becomes how do we connect these extra solar panels together to increase the voltage and power output of what’s already there.

The trick here when connecting solar panels together is to choose a connection method that is going to give you the most energy efficient configuration for your particular requirements.

Connecting solar panels together can seem like a daunting task when you first start to look at how it should be done, but connecting multiple solar panels together is not that hard with a little thought. Wiring solar panels together in either parallel or series combinations to make larger arrays is an often overlooked, yet completely essential part of any well designed solar power system.

There are three basic but very different ways of connecting solar panels together and each connection method is designed for a specific purpose. For example, to produce more output voltage or to produce more current.

Solar photovoltaic panels can be electrically connected together in series to increase the voltage output, or they can be connected together in parallel to increase the output amperage. Solar pv panels can also be wired together in both series and parallel combinations to increase both the output voltage and current to produce a higher wattage array.

Whether you are connecting two or more solar panels, as long as you understand the basic principles of how connecting multiple solar panels together increases power and how each of these wiring methods works, you can easily decide on how to wire your own panels together. After all connecting solar panels together correctly can greatly improve the efficiency of your solar system.

Connecting Solar Panels Together in Series

The first method we will look at for connecting solar panels together is what’s known as “Series Wiring“. The electrical connection of solar panels in series increases the total system ouput voltage. Series connected solar panels are generally used when you have a grid connected inverter or charge controller that requires 24 volts or more. To series wire the panels together you connect the positive terminal to the negative terminal of each panel until you are left with a single positive and negative connection.

Solar panels in series add up or sum the voltages produced by each individual panel, giving the total output voltage of the array as shown.

Solar Panels in Series of Same Characteristics

connecting solar panels together in series

In this method ALL the solar panels are of the same type and power rating. The total voltage output becomes the sum of the voltage output of each panel. Using the same three 6 volt, 3.0 amp panels from above, we can see that when these pv panels are connected together in series, the array will produce an ouput voltage of 18 Volts (6 + 6 + 6) at 3.0 Amperes, giving 54 Watts (volts x amps) at full sun.

Now lets look at connecting solar panels in series with different nominal voltages but with identical current ratings.

Solar Panels in Series of Different Voltages

solar panels in series with different voltages

In this method all the solar panels are of different types and power rating but have a common current rating. When they are connected together in series, the array produces 21 volts at 3.0 amps, or 63 watts. Again the output amperage will remain the same as before at 3.0 amps but the voltage output jumps to 21 volts (5 + 7 + 9) .

Finally, lets look at connecting solar panels in series with completely different nominal voltages and different current ratings.

Solar Panels in Series of Different Currents

solar panels in series with different currents

In this method all the solar panels are of different types and power rating. The individual panel voltages will add together as before, but this time the amperage will be limited to the value of the lowest panel in the series string, in this case 1 Ampere. Then the array will produce 19 Volts (3 + 7 + 9) at 1.0 Ampere only, or only 19 watts out of a possible 69 watts available reducing the arrays efficiency.

We can see that the solar panel rated at 9 volts, 5 amps, will only use one fifth or 20% of its maximum current potential reducing its efficiency and wasting money on the purchase of this solar panel. Connecting solar panels in series with different current ratings should only be used provisionally, as the solar panel with the lowest rated current determines the current output of the whole array.

Connecting Solar Panels Together in Parallel

The next method we will look at of connecting solar panels together is what’s known as “Parallel Wiring“. Connecting solar panels together in parallel is used to boost the total system current and is the reverse of the series connection. For parallel connected solar panels you connect all the positive terminals together (positive to positive) and all of the negative terminals together (negative to negative) until you are left with a single positive and negative connection to attach to your regulator and batteries.

When you connect solar panels together in parallel, the total voltage output remains the same as it would for a single panel, but the output current becomes the sum of the output of each panel as shown.

Solar Panels in Parallel of Same Characteristics

connecting solar panels together in parallel

In this method ALL the solar panels are of the same type and power rating. Using the same three 6 Volt, 3.0 Amp panels as above, the total output of the panels, when connected together in parallel, the output voltage still remains at the same value of 6 volts, but the total amperage has now increased to 9.0 Amperes (3 + 3 + 3), producing 54 watts at full sun.

But what if our newly acquired solar panels are non-identical, how will this affect the other panels. We have seen that the currents add together, so no real problem there, just as long as the panel voltages are the same and the output voltage remains constant. Lets look at connecting solar panels in parallel with different nominal voltages and different current ratings.

Solar Panels in Parallel with Different Voltages and Currents

connecting solar panels together

Here the parallel currents add up as before but the voltage adjusts to the lowest value, in this case 3 volts. Solar panels must have the same output voltage to be useful in parallel. If one panel has a higher voltage it will supply the load current to the degree that its output voltage drops to that of the lower voltage panel.

We can see that the solar panel rated at 9 volts, 5 amps, will only operate at a maximum voltage of 3 volts as its operation is being influenced by the smaller panel, reducing its efficiency and wasting money on the purchase of this higher power solar panel. Connecting solar panels in parallel with different voltage ratings is not recommended as the solar panel with the lowest rated voltage determines the voltage output of the whole array.

Then when connecting solar panels together in parallel it is important that they ALL have the same nominal voltage value, but it is not necessary that they have the same ampere value.

Connecting Solar Panels Together Summary

Connecting solar panels together to form bigger arrays is not all that complicated. How many series or parallel strings of panels you make up per array depends on what amount of voltage and current you are aiming for. If you are designing a 12 volt battery charging system than parallel wiring is perfect. If you are looking at a higher voltage grid connected system, than you’re probably going to want to go with a series or series-parallel combination depending on the number of solar panels you have.

But for a simple reference in regards to how to connect solar panels together in either parallel or series wiring configurations, just remember that parallel wiring = more amperes, and series wiring = more voltage, and with the right type and combination of solar panels you can power just about any electrical device you may have in your home.

For more information about Connecting Solar Panels Together in either series or parallel combinations, or to obtain more information about the different types of solar panels available, or to explore the advantages and disadvantages of using solar power in your home, then Click Here to order your copy from Amazon today and learn more about designing, wiring and installing off-grid photovoltaic solar electric systems in your home.

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475 Comments already about “Connecting Solar Panels Together

  • Peace
    I have a trailer with a solar system 12 volt 250 amp battery, 150 volt 60 amp controller 3 solarrip panels 40 volts 8 amps 280 watts
    The question is to connect the panels in parallel or in a column
    Thanks

    • You state that you have a 150 volt 60 amp controller, and three 40 volts 8 amps 280 watts panels.

      Then a series connection will give you: 3 x 40 = 120V at 8 amperes which is within your controllers input specifications.

  • I have been contacted today by a person who tells me that I can heat my hose to include hot water via 3 solar panels I do not see how this can be achieved. Maybe I don’t understand but can you offer me any advice, my current heating system is via a fuel boiler.
    Thank you

    • Solar Thermal Panels can provide sufficient Hot Water for the needs of a house and depending upon your daily consumption, 3 solar thermal panels may be enough. Photovoltaic solar panels as referenced in this tutorial generate electricity, and are not recommended for heating water.

  • Hello
    We are IT company from Turkmenistan.
    If we need a Solar Panel 2Volt 720Am, can we get a price from you?
    24 Battery 2 Volt 720A/hour and enough panels are needed to charge that much battery.
    24 pieces of these materials are needed in SET, the necessary parts will be in the box, we will open the box directly and do the installation, nothing should be missing, so we can install directly without looking for any parts here.

  • Hi there.
    I have a 5kva inverter 48v
    With 10 Solar panel
    (8pieces of 250watt & 2 pieces of 200watt)
    Can I connect the 8pieces of 250watt in series and connect the 200watt in parallel

      • Hi guys, really enjoyed reading this article. My house is entirely of grid.
        I have a 5.5 kw inverter with built in mppt charge controller, I have 8 x 495 watt @45.46 voc and 12.97 amps.
        I currently have these all wired in series but do suffer with some shading issues first thing in the morning and last thing at night. My panels are installed on a Lorentz tracker. The distance from the tracker to the inverter is some 150 feet.
        I also have other panels which I have already erected and wondered how they might play a part with the same installation.
        Photos and further info can be sent.
        Thankyou.

  • Hi there, I have 4kw grid tied, but have decided to add off grid set up. Growatt 5000 ES seems ? to fit the bill , 450V + 6000PV + 100A.
    So 550W panels now available 50V + 13A scratching my head, the nearest I can get is
    5 panels in series =13A + 300V.
    6 panels in parralel = 78A + 150V. Total 450V + 91A = 6050W.
    Would appreciate comments if this doesn’t sound right.

    • The PV specifications for the Growatt 5000es are Vdc 150 to 450 volts, Idc 22 amperes maximum, Max PV array power 6kVA. Your 550W, 50V, 13A panels will only allow for one 13A series string connected to the inverter.

      V = P/I = 6000/13 = 462 volts, if each panel has a Voc of 50V, then 462/50 = 9 panels. Thus you can have one series string of 9 PV panels producing 4950 watts at full sun. Although 8 series panels at 400Vdc maybe a safer option.

  • Hi there,
    First of all, thanks for a great article, which reallyl helps to clarify things.
    I’m still not 100% sure of what’s the most efficient/fastest way to use my two solar panels 100W (18V/5.5A) to charge my 2000W portable power generator with MMPT controller, which accepts 500W, 18-70V, 18A max.
    I have the possibility to use series or parallel cabling (both theoretical as the limits of the charging system won’t be reached with two panels, and practical as I have the two MC4 Y adapters for parallels cabling).
    The power generator only reports on the app the input/output wattage in real time, and it looks like there is no increase between 1-panel and 2-panel when cabled in parallels (if I disconnect one of the panels). I haven’t had a chance to try series yet.
    Would you have any recommendations?
    Thanks!

    • Clearly a parallel connection (18V and 11A at full sun) as you already have the MC4 connectors. Two 100W panels will always give you 200 watts at “full sun” whether connected in series or parallel.

    • Manni,

      I strongly recommend connecting your panels in SERIES.

      First, their 18 volt rating is under ideal conditions (bright sun overhead) and their output voltage could easily be as low as 16 volts (or lower) under less than ideal conditions. However, your MPPT solar charge controller is designed for voltages no lower than 18 volts which means your charge controller may effectively be “off” in many conditions where your panels are still producing useful energy. Connecting your panels in series provides a voltage (typically between 24 and 36 volts) which is well above your MPPT solar charge controller’s minimum design voltage, even in far less than ideal conditions, and yet will never get anywhere close to exceeding your charge controller’s maximum design voltage (70 volts).

      There are two more possible advantages. Connecting your panels in series keeps your maximum current at 5.5 amps which allows you to get the same energy production with smaller gauge wire than if you connect them in parallel. Second, if your system is charging a 12-volt battery, your panels may not always produce enough voltage to charge your battery when connected in parallel. (Charging a 12-volt battery sometimes requires voltages as high as 14 volts.) Connecting your panels in series virtually guarantees that your panels will be able to charge your batteries even in very poor lighting conditions (e.g. cloudy skies).

  • First im living off grid in a 33 ft RV. I now have five 100 watt panels in parallel connected to a 40amp mppt controller. Im using four Walmart Max batteries (because of cost and 2 yr warranty) 100 amp hr which is 400 amp hr. I have a 3000 watt inverter feeding one leg of a electrical panel. I used a 30 amp single pole breaker to feed a post beside my trailer similar to a campground. Being an electrician with little knowledge of DC I still connected said panel to a 10ft ground post as normally I would. I also ran wires under ground from a shunt with monitor to the tongue of the trailer into a small box to where the DC part of the trailer connected to the original batteries. All equipment and batteries are in a shed about 25 feet apart. All my wiring is 10awg. Batteries are wired together using #2 wire. All equipment is Renogy because I can get open boxes on Amazon cheaper then Renogy. My question is I want to increase my wattage but can’t add anymore panels because the controller can only handle 520watts. Can I get more power using twenty five 100 watt panels (since I buy one at a time) wiring 5 in series which would bring them to 90 volts (controller can handle 100v) then making 5 sets of that configuration in parallel which would still give me the 500 watts but at 90volts. will that do anything at all for me or should I just crap this system and save and buy bigger

    • Really, 25 x 100 watt panels is still only 500 watts. You need to rethink your math’s.

      Electrical Power = Volts x Amps (P = V x I). You say that 5 panels in a series string equals 90 volts, then each panel generates 18 volts (90/5). If you panel is rated at 100 watts, then the panel current I will be: I = P/V = 100/18 = 5.56 amperes.

      Now you say you want 5 parallel branches of panels. Thus 5 x 5.56 amperes equals a total current of 27.8 amperes. So your controller at “full sun” will see 27.8 amperes at 90 volts. As said previously, P = V x I then the power generated by your proposed array at full sun will be: P = V x I = 90 x 27.8 = 2502 watts in total, which it will be as: 25 x 100 = 2500 watts, and not your perceived idea of only 500 watts.

  • To mitigate low water flow rate and pressure in a solar bore hole water pump during lower sunlight periods, can an additional set of panels (identical to the existing ones) connected in parallel to the existing ones improve output without damaging the controllers/inverters during the time of pick sunlight?

    • Adding more solar panels is always a good idea as it increases the total installed wattage of an array, while providing more power later in the evening and earlier in the morning. How much extra DC capacity (the quantity and wattage of solar panels) is installed will depend on your inverters input parameters.

  • Can I hook five panels four of which are in parallel series and the fifth panel in tied in using a t branch to join all panels together

  • Hi. When connecting 4 x 100W solar panels together with a 4 to 1 MC4 connector, will the single cable between the connector and the Solar Charge Controller need to be a size larger than the cables from the solar panels? The single cable will be run in conduit within an insulated caravan roof/wall. Thanks

    • Generally, 4-to-1 MC4 solar connectors electrically connect the 4 photovoltaic panels together in parallel. A typical 12V 100W PV panel can potentially produce about 5.5 Amperes at full sun, so 4 parallel panels will give you about 22 (5.5 x 4) amperes. Then the size of cable you use should be rated to carry at least 24 to 30 amperes. The length of cable run in metres will also determine cable size to keep voltage loss below 5% with the diameter of conduit (20mm, 25mm, 32mm, etc) large enough to allow adequate air flow around the two cables.

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