Solar panels are great for powering appliances. Just switching one appliance to solar power can save you money. It can lead to you getting lower electricity bills. Fridges tend to use a lot of power. If you use solar panels for your fridge this can bring your monthly bill down quite a bit. Not only that but your fridge would work better too. However, you might not know what kind of solar panel would work well with your fridge. You need to figure out the right size. We will be discussing the right solar panel size for fridges in this article.
All The Info on Solar Panels
In order to understand what size solar panel would work best with your fridge, you must first understand solar panels in general. Solar panels contain cells. They are called photovoltaic cells. These cells are made out of silicon. They are placed between two semiconductors. The layering of solar panels is quite important. It allows them to work more effectively. The physical properties of silicon are important too. These physical properties make solar power generation possible. It’s an interesting physical factoid that governs our natural world.
The physical property of silicon that facilitates solar energy production is called the photoelectric effect. When sunlight hits silicon, it activates its electrons. The more these electrons move, the more unstable they become. This creates free electricity. The semiconductors then guide the newly generated power to your appliance. However, the current generated is AC, or alternating current. You need DC power to run an appliance. Usually this alternating current is sent to a power grid. It’s converted to DC here. You would need an inverter if you want the same effect at home.
There are two kinds of standard solar panels that you can get. Each type differs in its number of cells. Solar panels that are meant for residential use have 60 solar cells in them. They’re a little less than 18 square feet. Since you are probably going to put them up on your roof, knowing their square footage is important. It can differ by brand, though. So you shouldn’t assume that this is standard. However, 18 square feet is the general ballpark figure. Variations are usually minor. So you can rely on this as a good estimate. 60 solar cells is usually enough for a number of appliances.
Commercial solar panels are a little different. They usually have 72 solar cells in them. Some companies go for more solar cells. Some panels even have close to a hundred of them. However, they are rare. Such a high number of solar cells would make the solar panel too large and bulky. This would make them difficult to position. Which is why 72 solar cells are popular for commercial. The extra 12 cells generate a lot more power. They do this without adding too much to the weight or size of the solar panel.
72 solar cell panels are about 21 square feet. They need to be larger for extra power generation. They have the same depth, though. Between 1 to 2 inches is common for all solar panels. Regardless of how and where they are going to be used. An average residential system needs about 6 kilowatts of energy production. This much energy will make the solar system a worthwhile investment. Any less than this and the investment would not provide maximum value. You can opt for a higher power production than this too, of course. This is just the minimum that you should be going for.
Before putting solar panels on your roof, you should clear it up. Debris and other obstacles can reduce efficiency. A clear, flat roof is perfect. It can allow you to position your solar panels closely to each other. A full solar system will probably measure about 1000 square feet. It might be larger if you use commercial solar panels. A system this large can power an entire home. It will be more than enough for just one fridge. You might need an even larger setup if your home is large, though. Ask an expert if you are confused about this sort of thing.
Another important factor is how much your solar panel ways. This can impact whether or not your roof can support it. The average solar panel weighs about 18 kilos. Some can weigh as little as 15 kilos. Others might weigh up to 23 kilos. Try not to get heavy solar panels. They can be tough to install. They can also place a lot of strain on your roof. Energy savings don’t matter much when your roof has caved in. Weight matters less when you are opting for ground installation. The ground can bear any level of weight after all.
Things to Keep in Mind About Solar Panels
Solar panels have lots of advantages. They have some disadvantages too. Certain things will need to be kept in mind while using them. However, in general they are better than other options. Their disadvantages are not serious enough to warrant concern. They can be dealt with rather easily in fact. You can get a lot out of solar panels if you pay attention to problems they can cause. By acknowledging these potential problems, you can better prepare for them. We will start off by talking about the advantages.
For one thing, solar panels can provide free electricity. All they need is for it to be sunny and clear. The sun is a limitless resource. It will take billions of years to run out of energy. Hence, we can rely on it for the foreseeable future. Sunny areas can generate enough energy to power the entire world. This is because solar panels don’t need a lot of area. They can use a small space and generate lots of energy from there. This space saving feature is important to note. It impacts how and where solar panels can be used.
A solar farm is one application for solar panels. This is an array of solar panels set up in a sunny area. Some people are suggesting we build one in the Sahara desert. This hypothetical solar farm can generate more than enough power for the entire world. It’s just one concept, too. Another concept involves using building rooftops in cities. Every building will have a roof. Usually these roofs go to waste. Putting solar panels on them can make them a lot more efficient. It can help them to generate energy rather than just exist without any purpose.
Another advantage is that solar energy production does not generate noise. Solar panels operate silently. This means they can be used in cities without adding to the noise. They also don’t need a lot of maintenance. A regular dusting and sweeping would do the trick. Not a lot of other maintenance is required. They are also uniquely equipped to handle urban problems. Toxic air is one such problem. Toxins and fumes in the air can’t enter a solar panel. Because it has been sealed from every side. Hence, solar panels might just be the perfect urban energy creation solution.
Now come the challenges. One challenge is that solar panel supply needs to be closely monitored. Otherwise it could overload the grid. This only applies when the power is being sent back to the grid, though. It’s not relevant for home use. Regardless, figuring out what to do with surplus energy is important. Many people use batteries for this. The surplus energy can be stored in batteries. This power can then be used at night. The sun isn’t out at night. Hence, solar power can’t be generated. But batteries can make up the difference. Surplus solar power during the day is a great example of how sustainable this energy source can be.
Then we have the major issue that people face with solar panels. This is that they don’t work as well on a cloudy day. Maximum sunlight isn’t always available. Most places have some kind of cloud cover. Solar panels can work with any kind of visible light. However, direct sunlight always works best. It creates the reaction necessary to generate maximum power. Otherwise you won’t be able to power your fridge. So you should check out weather patterns. If it tends to be cloudy, you might need extra panels put in.
Another problem is that more sunlight means more heat. Yet, solar panels don’t work as well in extreme temperatures. Excess heat reduces their efficiency. So if you live in a hot area, don’t think that your solar panel would automatically work better. You need to cool it down every so often. The best areas are those with lots of sunlight but less than average heat. Not many areas conform to this standard. So you should factor that into your calculations. You need a stable power source to keep your fridge working. Good calculations can help you acquire such a power source.
Zeroing In On Fridge Power
Now that you know so many things about solar panels, you would need specifics. Specifics relating to your fridge, that is. First you need to remember that just a panel would not suffice. You need a few add-ons as well. These include things like inverters, batteries and charge controllers.
Solar panels generate solar energy. You need other accessories to make this energy useful by converting it from AC to DC. An inverter is what you need for this process.
Your fridge also needs a stable current. Fluctuations can damage it. They can also cause a short circuit in your entire home. This is what charge controllers are used for.
Also, you will probably need to use your fridge at night. You can’t do this without a battery. But before we get ahead of ourselves, let’s start off by figuring out how much energy fridges use.
Fridge specifications usually tell you voltage and amperage. These can be used to calculate how much power your fridge needs. Just multiply the voltage by the amperage. If your fridge has 120 volts and 5 amps, it needs 600 watts of power to operate. This is just the first step, though. A lot more needs to be done.
Other factors need to be taken into account as well. The temperature of your room is one good example. If your fridge is in a cold room, it would use less power. This is because its compressor would need to turn on less often. This is what uses the bulk of the power your fridge draws. Having a lot of cold things in your fridge reduces power consumption as well. The cold objects keep the temperatures low. The less you open your fridge, the less power it would use as well. This is because fridges have rubber insulation. If you leave your fridge closed, it could stay cold inside for several hours even if the fridge is off.
Once again, the air compressor is what uses the bulk of the fridge’s power. It needs a voltage surge while starting up. After the startup the level of power it uses tapers off. Batteries can handle this level of volt usage. They can provide up to 12 volts of electricity. This is enough to get your fridge up and running. Regular supply can then take over. You should look at your batteries maximum amperage, though.
This amperage will be divided over the number of hours the battery can operate. This usually maxes out at around 20 hours. After this point, your battery would need a break. Hence, if your battery says it can provide 200 amps, you should divide this by 20. This means that your battery would be able to provide 10 amps per hour. This is more than enough to power a fridge. You should still calculate its ideal power supply, though. This will help you keep the current stable. It can also help you figure out what kind of solar panel setup you need.
As we have said before, wattage is the product of voltage multiplied by amperage. This gives you the number of watts of power your appliance needs to run for one hour. In our example, the number we came upon was 600 watts. A fridge with this many volts and amps needs 600 watts every hour to work. Hence, your solar panels should be able to provide 600 watts an hour. You should go for more than 600 watts, though. A solar panel might be efficient, but other things added to it might be less so.
The inverter is particularly problematic here. It’s very rare for an inverter to be 100%. It’s more common for the efficiency to be at about 50%. You can find many inverters that offer an 80% efficiency rating, though. This means that they would be able to invert about 80% of the AC current that your solar panel produces into DC.
Hence, by this calculation your solar panels should generate 750 watts per hour. Only then will your 80% efficient inverter provide enough of a current to keep your fridge running. It’s better to be safe than sorry, so going for 1000 watts might be even better here. The excess will go to your battery anyway.
All of that said, you shouldn’t take any of this as objective truths. It all depends on people’s lifestyles as well. If you live alone and are at work all day, you will open your fridge less. This would lead to lower power consumption. So you can get away with using fewer solar panels if this is the case. You might also have more than one fridge. This doesn’t mean double power consumption, though. They can share power consumption and reduce overall usage.
You should also consider how much food you have in the fridge. The more food you have, the less energy it would need to keep running. Cold food in the fridge would maintain temperatures. As you can see, there are a lot of variables at play here. This doesn’t even include things like sunlight levels or weather patterns. These variables are just associated with the fridge itself. Where you install the solar panel matters too. As does the overall efficiency of said solar panel. You might need more solar panels if you buy cheaper ones. Keeping all of this in mind is necessary.
You do need an average that you can rely on, though. If we take everything as an average, you would need about 4 solar panels. Average solar panels produce 250-270 watts per hour. An average fridge and freezer combo needs 1000 watts per hour. By this logic, four solar panels will be sufficient. Although the numerous variables might make you want to double check just to be sure. Always go for excess power production. Less power than you need can never work properly. Excess power, though, can just be stored in the batteries for later use.
It can be useful to think of solar power as rainwater that you are collecting. Both things require the use of your roof. One can be particularly useful for energy supply. But the metaphor still remains valid. The more space you dedicate on your roof, the more rainwater or solar power you would be able to collect. In this example, your battery is like your tank. You are trying to fill your tank up with water. The more funnels you have, the more efficient this would be. Each watt in your solar panel is like an extra pipe. The more watts you have, the more power you can collect.
This example is more useful than you think. It goes even deeper. For example, the more water you have in your tank the greater the water pressure below would be. You can add a tap to your tank to release this pressure. Now, the pressure with which the tank is filling up is the voltage. The amps is how much water can actually come out of the tank. This depends on how big your tap is, or how efficient your inverter is. Thinking about solar power like this is great. It helps you understand how the various elements come into play.
Finding a Solar Battery
It’s always better to use batteries. Your solar panel might not have the ideal wattage for your fridge. You can collect this power in batteries. It can then be distributed in a stable manner. You can keep the wattage from your battery optimal. However, you do need to choose the right battery. Your choice of battery is rather important. It can determine how efficient your power supply can be. It also affects how long you can run your fridge. Try to get a battery that lasts the night. Otherwise your fridge might turn off.
It’s difficult to maintain a consistent power supply from a solar panel. The wattage can go up or down. This is based on how much sunlight is available. On days of strong sunlight, a power surge can occur. Low sunlight levels could lead to low voltage. Both of these situations will damage your fridge. Using a battery can extend the life of your fridge. It can also ensure optimal cooling. You don’t want to damage your fridge in your pursuit of renewable energy. This defeats the purpose of trying to reduce utility bills.
You should start off by seeing your battery capacity. This is measured in ampere hours. You can find out how many watts it can store by multiply amps with volts. Just like we showed you above. This can give you a total of how many watts you can store. You can then use your battery accordingly. Knowing how many watts you have at your disposal is useful. You wouldn’t have to worry about your power going out all of a sudden. If it does, you would know that something is probably wrong. After which you can try to think of ways of fixing the issue.
Pay attention to depth of discharge. This tells you how much power your battery would allow you to access. Most batteries don’t discharge completely. This would damage their functionality. Instead they give you a portion of their total energy. As you can see, there are lots of inefficiencies take into account. These inefficiencies will disappear over the years. However, right now we need to be practical. So taking depth of discharge into account is important. It can tell you how much of the power that is stored can actually be used. Thereby preventing problems down the line.
A 50% depth of discharge is terrible. New dry lithium batteries have been released. They can manage up to 80% depth of discharge. Some even discharge 90% without any damage to the battery. Deep cycle batteries are particularly effective. This is because of their high depth of discharge. Remember that batteries produce heat. Those with a higher than average depth of discharge tend to release more heat. You will have to account for this heat because it reduces solar panel efficiency. Weighing all of your options is crucial here. You can’t be overly optimistic in your calculations. This can cause huge problems down the line.
Solar power is all about environmental sustainability. Hence, you should remember that certain kinds of batteries are bad for the environment. Lithium ion batteries are pretty bad. However, they last quite a long time. Some can last up to fifteen years. Cheaper batteries won’t last nearly this long. They last on average six years. When you consider this, their lower price range becomes less relevant. It becomes more about getting something long lasting. Since your solar setup would be useless without the right kind of battery. Long lasting batteries are definitely worth the price. They can keep your fridge running smoothly as well.
The Ideal Solar System For Your Fridge
By this point you know that solar panels aren’t everything. The solar system they are a part of is what matters. So you’re not just trying to see the right solar panel size here. Rather, you’re trying to figure out what the ideal solar system size is. We have enough information to make these calculations now. These calculations are basically a repeat of what we have done before. We just need to contextualize this information so that it can stay relevant.
You first need to figure out the total amount of watts that are being used. Calculate this over a 24 hour period. A wattmeter can come in handy here. It will save you from endless calculations. You can get a straight answer to how many watts are used over a 24 hour period. You can factor in battery capacity as well as solar panel efficiency. This would give you a pretty good estimate of ideal solar system size. Your fridge will be a pretty big part of the overall power usage. This is because it stays on all day. Most appliances are only used when necessary.
Divide the total number of amps that are generated by the number of sunlight hours you would get in a day. Usually, seven hours of sunlight is a good number to go by. You might get more sunlight than this. But it won’t be enough for your solar panels. Remember, they don’t just need it to be light outside. They need full sunlight. This only occurs for a small portion of the day. 7 hours of direct sunlight is rather generous. However, it tends to be accurate in reasonably sunny parts of the world. Some parts of the world even get 10 hours of sunlight a day. Hence, 7 hours is a good average estimate.
If you get 7 hours of sunlight a day and you get 70 amps, this means 10 amps per hour. Now multiply this by the number of volts coming from your amp. 21 is a good average number. These numbers means that 210 watts are required for your fridge. Remember that this is an ideal requirement, though. Most situations will not be this perfect. So it would be good to be a little more practical. You can do this by opting for a bit of a buffer.
Take into account occasional cloudy days. Some efficiency will be lost due to the heat. Your inverter would lose a bit of power along the way as well. Your batteries will not give you access to all of the power they contain. With all of these things in mind, 300 watts seems like a more reasonable figure. It will prevent cloudy days from causing power outages.
This is just for one fridge, though. You will need a lot more power for your entire home. 300 watts isn’t all that much, though. You can use it relatively easily. A small solar panel setup is enough for even the largest of fridges. Focus on buying efficient inverters and charge controllers. This will minimize power wastage. Batteries with high depths of discharge are great as well. Buying good add-ons can lead to a better solar panel experience. They can help you power your fridge with fewer solar panels than you might have otherwise required.
It’s amazing how complicated such a simple question can be. Fridges are essential to our daily survival. But there is no set way to define how much energy they need. If you want to keep things simple, just get four standard solar panels. The battery and inverter you get are more important anyway. You can be more specific too if you want. But four solar panels is the standard that has been set. The calculations are accurate as are the averages. More than four is great since it would power more appliances. Less than four wouldn’t be sufficient, though. It would lead to your fridge being unable to run for twenty four hours a day.