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Solar Panel Voltage – All You Need to Know

Solar Panel Voltage

What is Voltage?

Increasing the voltage if your solar panels can improve their yield immensely. But before we get into the nitty gritty of how this can be done, let us take a moment to define voltage. Voltage is the pressure of an electric current that pushes the flow of charged particles, called electrons, in an electrical circuit. Think of water running through a pipe. The speed and intensity of the water is the voltage, and the flow is the current.

Voltage in Solar Panels

When light hits the surface of a solar panel, a small amount of voltage is created. This happens when light hits the junction, called the p-n junction, that is placed between the silicon semiconductor and a metal, in this case silver. This current then flows through wires to the inverter and ends up powering your electronic devices.

As you can imagine, solar panels, like any other electronic device, do not have a uniform voltage rating. Some have higher voltage ratings than others, but what does this mean? Are lower volt solar panels always worse than higher volt ones? What should you do if you have a solar panel that has a low volt rating? How can you increase the voltage of a degraded solar panel? This article will try and answer these questions and more.

Disclaimer: You’re probably going to read the world “volt” and its variations more in the next five minutes than you will in a month, so brace yourself. And if this isn’t the case, then you have my admiration, you sicko.

Solar Panel Voltage: How Many Volts?

Different panels have a different voltage rating, and so they produce different amounts of volts. All of this depends on the panels power capacity and is usually mentioned. However, solar panels generally have a power output between six to twenty-four volts. This is because solar panels are typically designed to produce a low voltage DC (direct current). The most common voltage produced by a typical solar panel is 12 volts, but this number can jump to 17 volts during peak electrical production. How did this happen, you ask? Well, that is because basically a solar panel has two voltage ratings:

  • The Reference Voltage
  • The Operating Voltage

Reference Voltage

The reference voltage rating is fixed for every panel (mostly at 12 volts) but the operating voltage can go up to 17V or even higher if necessary. Reference voltage is necessary because a solar panel receives varying amounts of sunlight, its output also varies. This flux can damage any electronic equipment running on solar power. To prevent this, an inverter matches the voltage of the solar panel to another source of power, usually the grid, or a battery system. This keeps the current smooth at 12 volts and prevents damage to electronic equipment. Rooftop solar needs a point of reference to match the voltage with. That is why it is called a reference volt.

Operating Voltage

The operating voltage is the volt at which a solar panel is currently operating. It estimates thee actual output of a solar PV system, and it also indicates what voltage battery system a particular solar panel is designed for.

Is Going High Always Better? High vs. Low Voltage Panels

Unless you’re new to the solar industry, you are probably familiar with the longstanding feud of high vs. low voltage in solar panels. It’s right up there with Ketchup vs. Mustard and Xbox vs. PlayStation (that last one is a joke, since we all know that the correct answer is PC). Suffice it to say that there are cases to be made for both, but let’s break it down. In the interest of preventing nosebleeds and migraines, let us keep it simple. A higher voltage is usually better, because it means that you can draw more power from your panels and power more devices. A higher voltage means each panel has more power, and so you will need less panels for your system overall. Inverters also work better with high voltage panels.

These panels can be rated as high as 60 to 72 volts, whereas you average, off-the-shelf panel is rated for around 18 to 30 volts. However, unlike us, most people aren’t nerds living in basements, and so they don’t really need to know the intricacies of higher and lower voltage. For the most part, all they need to know is that the wattage matches their specifications. But bear in mind that a higher voltage rating will mean a higher load capacity for your panels. These panels will simply be able to do more than low volt panels.

Are High Voltage Solar Panels Worth it?

Well, that depends. There is one downside to high voltage panels: the cost. If you’re willing to stomach it, then we definitely recommend going for them. As with everything else, money buys quality. High voltage panels are usually better constructed and make use of better materials, which protect them in the long run from extreme temperature and UV related damages. Ultimately, it’s up to you to decide what works best for you, and that is always better. But if you want our opinion (please say that you do, I need the validation) we at Integra Solar always recommend quality over affordability. The reasoning is simple. Sure, high quality panels cost more in the short term, but they last much longer and make up for their inflated price many times over. Also, remember that solar panels are a multi-decade investment. If you’re going to be stuck with something for three decades, why not make it a good something?

Putting Price Into perspective

What exactly factors into price considerations? What should you keep in mind wen making a purchase? Well, the first thing to consider is wattage per square foot. To be precise, the more wattage per square foot a solar panel has, the lower its cost will be. One way to boost this number is by purchasing high voltage solar panels. This means that you will also need less panels to boot. So, while an individual high voltage panel from a top tier company like Jolywood may be more expensive than a low voltage solar panels from a lower tier company like, say Longi, you can bet that the former will not only produce a higher voltage, but you will also need less panels. A high voltage panel also means better construction, better quality control and better materials. They cost more, but last longer. Best be sure to consider these factors when making a purchase. Keeping things cheap in the long run does not always pay off.

The Pros of High Voltage Solar Panels

  • High voltage solar panels produce more electricity faster, as they are more powerful.
  • They have a consistent power output and are more useful as a failsafe or alternative source of power.

The Cons of High Voltage Solar Panels

  • Money: They cost more, not only to purchase, but also to install.
  • High voltage solar panels are more difficult to install, as they need to be grounded properly, otherwise the risk of shock is fairly high. But this should not be a problem if you call a professional company to do the installation for you; a professional company like Integra Solar Australia. (Shameless self-promotion completed)

The Pros of Low Voltage Solar Panels

  • They’re cheap/ low voltage panels are easier to purchase and to install. The initial investment required is low, and though we would not recommend it, a determined individual could even install low voltage panels by themselves.
  • The risk of shock is low, so they’re safe to install, or at least safer than high voltage panels. Though we would never suggest that you tempt fate and go about installing panels yourself.
  • They are lighter than high voltage panels, and this makes them easy to transport and store.
  • They are excellent for small projects that do not necessarily need a lot of electricity. For streetlights or other public utilities, low voltage solar panels may just be ideal.

The Cons of Low Voltage Solar Panels

  • If you want to go independent rom the grid, low voltage solar panels will end up costing you more in the long run. They are not ideal for large projects that require a lot of power.
  • They are not ideal for commercial use, since more panels will be needed to power commercial infrastructure, eating up limited space.
  • Any place that has space constraints should avoid low voltage panels, since expanding the solar energy system will become difficult in the future.
  • Low voltage solar panels are not ideal for living ‘off the grid.’ Since they produce less electricity, an off the grid solar PV system will have less room for error and less buffer-space for low yield days. If you’re planning to supplement your grid power with solar energy, then a standard voltage system may do just fine, but if you want to rely as much as possible on solar energy, ten low voltage systems may not be for you.

The Main Causes Behind Reduced Voltage

Most solar panels will not have any output degradation for at least twenty-five years, especially not Aleo panels. The company is actually so confident in their panels that they offer a performance guarantee for their products. Talk about sure footing! But I digress. Most modern panels in the market are unlikely to suffer any degradation right out of the box. With proper care and maintenance, they should have no trouble maintain 80% of their efficiency for 25 years. And should you buy RECOM panels, then you’re probably looking at over 30 years. However, like all good things, solar panels too begin to show their age. One of the surest ways a panel shows its age is when it suffers from failing efficiency and a reduced production. One of the main reasons of this is reduced voltage output.

Microfractures and Hotspots

One of the reasons for reduced voltage is the development of a hotspot, which appears when solar panels develop minute fractures called microfractures in the solar cells. Now, manufacturers have found some workarounds to this. RECOM, for example, has developed a shingled design that reduces the stress on the solar panels from external elements like dust and snow pile-up. Not only does this greatly extend the longevity of RECOM’s panels, but also improves their efficiency over extended periods of time. This is just another case for quality over affordability. Nevertheless, microfractures cause solar panels to lose voltage capacity, which in turn causes the overall voltage of the solar array to be reduced. We’ve talked about this extensively in our previous article on wattage and voltage, give it a read.

Defective Inverters and Improper Wiring

So, technically this is not a problem with the solar panels, but a defective inverter, junction box or charge controller can significantly lower the voltage output of a solar PV system. This just goes to show that a solar energy system can have multiple bottlenecks. There is no point in buying an expensive, top-of-the-line solar panel and then mating it with a substandard solar inverter or battery system. That is just asking for trouble. It is best to avoid any such bottlenecks, and if you’re investing in a system, be sure to buy the best that you can afford. This will save you from a lot of headaches and phone calls later and will significantly improve the longevity of your energy system.

Improper wiring is another completely avoidable issue that can severely hamper the efficiency of your solar PV systems. This is why we always recommend getting a top-tier solar installer to do the job for you. Nevertheless, be sure to look for frayed wiring, blown out fuses and loose connections. Any of these will hamper your production immensely, if not downright stop your solar energy system in its tracks. Even if the sun is shining, you might be scratching your head wondering why production is so low.

But faulty connections can cause more than just a poor output. Frayed wiring, for instance, can cause fires. Considering this, a reduced output does not seem so bad. I know I sound like a broken record at this point, but you can avoid all of this by installing quality parts from quality suppliers. Loose cables should be tightened, defective wires and substandard inverters replaced as soon as possible.

UV Discolouration

UV discolouration (a phenomenon in which UV light causes colours to fade) also affects voltage output. UV discolouration is more pronounced in cheaper solar panels. Solar panels are generally resistant to UV discolouration, but cheaper solar panels are made from cheaper materials, and so they are more susceptible to discolouration. Prolonged exposure to the sun will make even the best panels turn from a sparkly black to a sickly yellow brown. High quality panels, however, will take a lot longer to get discoloured, because they make use of better materials. There is no way to prevent UV discolouration, and you will probably start noticing it in the first few years of operation. The only way to avoid it is, you guessed it, investing in high quality panels. The only way you can mitigate this problem is by trying to replace the glass covering of your solar panels with UV resistant glass. Again, this is not something you should attempt on your own, as it will void your warranty, but give us at Integra Solar Australia a call, and we can hop over and see what needs to be done. Remember: you can call us up any time without any sales commitment and just have a conversation! We’re always happy to help! If all of this sounds like too much work, then you should really just (do I even need to say it again?) buy a high-quality panel and sidestep this entire hassle.

The Shadow Effect

Solar panels are very resilient. They produce impressively persistent and high amounts of voltage output even when the sun’s intensity varies throughout the day. They truly are a testament to human ingenuity. However, to function properly, panels need to be installed correctly. If they are not, the entire system will suffer from diminishing returns. Solar installers like Integra Solar will conduct something called a shade analysis before deciding on the placement of your panels. This involves looking at hoe different objects like buildings and trees will cast a shadow during the days and how panels can be best placed to avoid them and maximise exposure to sunlight. If any panel, or even a considerable part of one panel is obstructed by shade, the output of the entire array will suffer. Now, this can be avoided by using multiple inverters and a correct wiring technique, but even so, it would be a shame to leave a panel out of operation for an extended period of time. Therefore, it is advisable that customers take shade into account before choosing where to install their array. And if some amount of shade is unavoidable, the compromised panel should be wired in a way that will isolate it from the rest of the panels and prevent it from bringing down the output of the entire solar energy system.

Temperature

This is a tricky one. Solar panels work by exposure to sunlight, yet they are susceptible to temperature variations. The irony is palpable. Modern solar panels are designed to operate in a variety of different weather conditions, yet they have a comfort zone too. This means that your panels will continue to operate in extremely hot or cold conditions, but you can expect output to suffer. For the most part this is not noticeable, but experiments have shown that reducing the temperature of solar panels can significantly boost their output. It turns out that solar panels do not operate as well in extremely hot temperatures. Remember, sunlight, not heat, determine the efficiency of a solar panel. It is a misconception that the hotter the area, the more efficient the solar panels will be. In fact, the ideal climate for solar panels is one that is cool with ample amounts of sunlight. Voltage output drops as temperature rises. This is because high temperature tends to reduce the ‘bandgap’ of the semiconductor called silica, which is extensively used in solar panels. This affects the performance parameters of the panels in question. One of the affected parameters is the voltage. Now, there is unfortunately, little we can do to combat the temperature rise. But in the grand scheme of things, solar panels are going to help us combat climate change and global warming. So, who knows, the solar panels of the future may have to deal with a climate that is not as hot as our own, and so they may be more efficient. Talk about planning ahead! For now, the only thing you can do is a rain dance to appease the weather gods. The fecundity of such a measure is, however, debatable.

Dust, Dirt and Debris

The three dreaded Ds of the solar industry, in all honesty, are a bit overrated. Dirt, dust and debris are airborne particles that may accumulate on a solar panel and reduce their exposure to the sunlight. If you live in a particularly dry region, then this can become an issue. However, most solar panels are installed at a slanting angle, so most of the dust, dirt and debris will just slide off harmlessly. Any stubborn portions can be washed away with an annual or bi-annual cleaning. It only becomes a problem if you ignore it. if you live in a dry area and let your panels go without cleaning for years, then you can expect to see a significant drop in voltage output. Furthermore, as with shade, poor functionality because of debris related obstruction will cause the entire array to suffer. Like a chain, a solar array is only as efficient as its weakest panel. But again, this can all be avoided by cleaning your panels once or twice a year, depending on the amount of precipitation your area gets.

Improving Solar Panel Voltage Output – Can it be Done?

The good news is that output voltage can definitely be improved. Let us take a look at the best ways you can improve your output.

It’s All in the Connections!

The simplest way you can do this is by making sure that your solar panels are connected in the correct configuration. The trick here is to pick a connection configuration that will maximise your output and provide you with the most energy possible. There are many ways to connect wires in solar panels, or I should say many right and many wrong ways to do it. Depending on how your solar panels are wired, your output can increase or decrease significantly. Reader beware, we are going to delve into a somewhat technical topic, so if you feel like this is a bit overwhelming, feel free to take my advice and just ring us up. Seriously, Integra Solar’s specialists will just do all of this for you. From purchasing solar panels to installing and connecting them, we’ll guide you through the entire process keeping your present needs in mind, while leaving room for future upgradability.

Approaches to Wiring

We’ve written a detailed article on the two main approaches to wiring earlier. Do give it a read if you want to understand the nitty gritty of it all. Suffice it to say there are two ways to wire solar panels:

  • Series Wiring
  • Parallel Wiring

Series Circuits

For the purposes of this article, we are only going to look briefly at the series wiring approach, given that this is the best way to increase your solar panel’s voltage output. In a series circuit, the current has only one path to travel along. Therefore, all of the current has to flow trough all the loads. A load is the power consumption of all the devices attached to the solar PV system.

A series circuit is a closed, continuous loop. If it is broken at any point, the entire series will cease to function. Think of it as a string of old Christmas lights from back in the day. If one light goes out, the entire string goes dark.

Solar panels, like batteries, have two terminals – one of which is positive, and the other is negative. In a series connection, the user connects the positive terminal of one panel to the negative of the other. When two or more panels are connected in this manner, you get a PV source circuit. When solar panels are wired in a series, the voltage of each panels adds up, while the amperage remains the same.

The Result:

The result of a series connection is that the voltage of the solar array increases by the sum of the combined voltage of each solar panel. What does this mean? Well, if you have two panels rated at 40 volts each connected in a series, your combined series output will be 80 volts.

One Thing to Consider

Before going for a series connection, a user is best advised to ensure that all their solar panels have the same voltage rating. This is why you should seek professional help before making a purchase. Depending on whether you want to max out your wattage or voltage, your solar supplier will give you different recommendations on what to buy. Since we are talking about voltage, make sure that all the panels you purchase have the same voltage rating. This is because the whole array’s voltage will be limited by the output of the lowest rated panel. So, if you have one panel with an output of 80 volts, paired with a panel rated at 40 volts, the 80-volt panel will only operate at 40 volts. Half its production capacity will go to waste and remain unused.

Throw Money at the Problem

One sure shot way to improve the voltage of your solar panels is to throw money at them, figuratively speaking. This works for most things in life, mind you, but then again, you probably already knew that. Even so, you can increase your voltage by adding in more panels to your solar array, or you could stack two identical inverters in a series of 120 volts to get an output of 240 volts. This will include buying more panels or inverters, but this is the surest way to increase the voltage of your panels. Stacking inverters in a series works just like stacking solar panels: positive to negative. But honestly, you should not do this yourself, unless you are a trained electrician and know what you are doing. Best leave playing with high-powered wiring to the professionals.

Concluding Thoughts

If you made it this far, then congratulations! Hopefully, you’re a little bit wiser in the ways of solar panels and voltages. Bring up your newfound knowledge in the next family dinner and watch everyone’s eyes roll. That’ll be a neat party trick! But my weak jests aside, we hope you found this article useful, and hopefully it will make you a bit more informed on what to consider when purchasing your next (or first) solar panels. At Integra Solar, we strongly believe in consumer education. This is not to insinuate that consumers are uneducated, but the more information you have, the less likely you are to be swindled or sold a substandard product. We will all be better off if everyone is more informed, not just about solar panels but about all things in general.