Understanding how solar panels work will help you tailor-make your solar setup to suit your needs. Here’s everything you need to know about solar panels.
Getting your solar panel setup bang on is vital to being able to tour and stay ‘off-grid’… As long as you have water and food to last, power is the next most crucial ingredient to extended stays in the bush. Understanding how your solar panels work will help you get the most out of your setup. To help with this yarn, we spoke with the boffins at Redarc.
How do solar panels work?
Solar, or photovoltaic (photo = light; voltaic = voltage/electricity) panels, whether monocrystalline, polycrystalline, or amorphous all work in essentially the same way. Energy and light from the sun knocks electrons loose from silicon atoms (the most common construction material used) on the top side of the cell to the bottom, creating an overbalance on the bottom of electrons. The only way those electrons can get back to the other side, is via the positive wire, through your battery (charging it on the way through), and back up the negative wire to the panel. Throughout the process nothing is used up; the electrons continue to travel around the circuit, equalising themselves out as more are knocked through, charging your batteries as they go.
Understanding panel efficiency
Panel efficiency boils down to how much electricity you can extract from a panel of a given size. Clear direct sunlight overhead supplies around 1000 watts per square metre. A good quality solar panel will run at around 16-17 per cent efficiency, meaning a one-square-metre panel, in direct, clear sunshine, will generate approximately 160-170 watts of energy. Cheaper panels will often generate less than that, but we’ll talk more about that below.
However, it goes beyond watts per square metre, and for those of us trying to reduce weight from our four-wheel drives, another way to look at it is watts per kilogram. Where the amorphous cells, like those used in some solar blankets, really shine is in their weight difference. Your average alloy framed monocrystalline or polycrystalline panel that you can bolt to the roof or unfold and face to the sun would be likely to generate approximately 10 watts for every kilogram. When you put that against the amorphous panels, they will generate upwards of 25 watts per kilogram. From a weight perspective, amorphous panels are much more efficient, however do command a premium in price.
Size of Shadow
Further to the efficiency of the panels, is what is known as the ‘Size of Shadow’. The amount of power generated by a solar panel is proportional to how much sunlight is shining on it. Therefore, the bigger the shadow the panel makes on the ground behind it, the more energy it will generate – a panel at 45 degrees to the sun (with a smaller shadow than at 90 degrees), will not generate as much as a panel perpendicular to the sun. To get specific, at 45 degrees, it will generate 70 per cent as much power (Cos 45 degrees = 0.7). This also does not consider reflected sunlight off the glass or dirty panels, which reduces efficiency further again.
Where you can maximise the size of shadow, is if you’re setting up a foldable panel, position it so the shadow it makes on the ground behind it is as large as possible. You will achieve this by ensuring it is perpendicular, or at right angles to the sun. In so far as shade over the panel is concerned, having the panel in full direct sunshine is critical. Ten per cent shading over a monocrystalline panel will reduce the energy generated to near zero, whereas the same shade over an amorphous panel will still reduce the output, but not as much.
Regulated or unregulated panel
When utilising your solar set-up with a dual input BCDC charger, you will need to run the panel directly into the BCDC charger, without using a regulator. All of REDARC’s BCDC dual input chargers have a built-in MPPT solar regulator, so like any regulator, it requires an unregulated panel on its input. Should you attempt to connect a regulated panel into a BCDC dual input charger, it’s likely the BCDC solar input won’t even turn on. If your panel has an inbuilt regulator that you can’t bypass, you will need to connect the panel directly to your battery, or alternator/main battery input on your charger.
How much solar power do I need?
There are many calculators out there to help you work out how much input you’ll need, for example REDARC has one at https://www.redarc.com.au/calculator/solar. Within the calculator there are different examples of appliances you may own to tally up your power requirements, from fridges to stereos, and LED lighting. There are also apps available for iOS and Android devices that will help calculate your solar requirements.
The simple rule of solar is ‘You need a battery big enough to supply all your electrical needs when the sun is not shining and enough solar panels to replace all that (plus an extra 20 per cent) when the sun IS shining’. An even simpler rule is ‘You can’t have too much solar’. It’s also worth considering where you’re touring, as different areas of Australia receive different amounts of sunlight per day; ensure you are taking sunlight hours per day into account; it will be shorter in mountainous country, and in winter.
Are cheap panels just as good?
Simply put, no. Why would you choose a brand name, like REDARC, over no-name, cheapy, ‘eBay’ panels?
- The panels will output rated power or better – not just claim arbitrary numbers to sound the best;
- They use only the highest efficiency ‘A’ grade cells, meaning maximum cell size with minimum imperfections – not from the ‘factory seconds bin’;
- The portable black blankets use top-of-the-range SunPower cells;
- They utilise genuine industry standard Anderson plug connections; and
- They have first-class tech support, and a massive network of installers and technicians to help out with anything you need, or any issue you’re having.
As with everything, the poor man pays twice, and when you’re looking to get off-grid for weeks at a time, you really don’t want to have to run your 4X4 for a few hours every day to stop the fridge falling over and wiping out your food.
This article originally appeared in Issue 37 of Pat Callinan’s 4X4 Adventures.
How To Connect Solar Panels To Battery?
The benefits of solar panels and battery pairing are not new to Aussies. Being big on renewable energy use, solar panel and battery packages are popular in various fields in the country including residential, commercial, and recreational sectors.
If you’re a newbie venturing into the world of solar power and were initially amazed at how beneficial solar panels are, you’re in for a bigger better surprise once you pair them with a solar battery. This power pack mainly serves as a storage for the energy initially generated by your panels, which is why they are often referred to as solar battery storage.
Sounds really nice, right? But before we get all excited about going solar, let’s address this pressing question: how do you connect your solar panels to a battery? Sure, it’s mostly your installer’s problem, but having basic knowledge about this is essential for anyone switching to solar energy use. It might even save you from a costly installation or repair job!
How To Connect Solar Panels To a Battery: Step-By-Step Process
Step 1: Mount Your Solar Panels
Did you know that your solar panel’s position largely affects its efficiency? This is why aside from mounting them securely, it’s also important to angle them in a way that they’ll get enough sunlight exposure. This is particularly important if you’re installing fixed solar panels since these can be hard to adjust once they’re installed.
Step 2: Set up the solar charge controller and battery
Most solar panel setups use a standard 12V battery but regardless of your power pack’s voltage or capacity, the most crucial thing is to use a solar charge controller in between it and your solar panels. This regulates the energy generated by your panels which will flow into your battery and help avoid overcharging as well.
The instruction for connecting the regulator to your 12V battery is usually found in the manufacturer’s instructions and are simple enough to follow, so make sure to refer to them throughout the entire process.
Important: Charge controllers can either be PWM regulators or MPPT solar charge controllers. Of the two, MPPT is known to be more efficient—you might want to consider this when shopping for a regulator.
Step 3: Test Your Solar Charge Controller
After successfully connecting your charge controller to your battery, turn it on to see if it’s working properly. This is where the advantage of MPPT controllers also comes in—they usually have more advanced features such as an LCD screen, which makes testing and tracking so much easier.
Step 4: Connect Your Charge Controller To the Solar Panels
Again, you’re likely to find the instruction for this in the manual which explains everything up to the wiring process you should follow.
At this point, you would also need to consider installing a power inverter, especially if you’re running electronics that require AC power. Solar panels generate direct current or DC power and while you can charge a battery for this, it’s not suited for running large appliances and would have to be converted to AC current by an inverter.
Do You Always Need To Pair Your Solar Panels With a Battery?
Investing in a solar battery along with a good set of solar panels has tons of benefits. For one, these allow you to store energy and use it at a later time which can tremendously reduce your monthly electricity bills. It’s also a good option for backup power in case of an outage or a main source of power for those living off the grid.
However, to ensure you’ll get the most out of your money, figure out your daily power consumption first. A battery may or may not be suited for you depending on how you plan to use it plus, it can be pricey too. You don’t want to make the mistake of buying and not being able to maximise its benefits. You can ask help from a professional to determine if installing a battery in your solar system is a good idea and if not, what other options are better for you.
If you do end up getting a power pack, opt for a lithium deep cycle battery such as a LiFePO4 battery for best results. These are superior in terms of overall performance and safety, perfect for use as a storage battery.
Ready to buy your solar essentials? Visit us at Outbax for great picks at even greater prices. We got them all here—flexible solar panels, 100Ah lithium batteries, and even power bundle kits! Visit our website today and start marking your picks.
How to Solar Power a 12V Fridge
Just so you know, this page contains affiliate links. If you make a purchase after clicking on one, at no extra cost to you I may earn a small commission.
In this tutorial, I’ll show you step by step how to solar power a 12V fridge.
In fact, these are the exact steps I used to create my own solar powered mini fridge.
The good news is solar powering a fridge isn’t too hard. I’ll cover all the parts you need, as well as some tips on which solar panel kit and battery to get.
Video: How to Solar Power a 12V Fridge
Here’s a 40-second video overview of this tutorial. Check it out below and consider subscribing to my YouTube channel if you like DIY solar videos like this!
- 100W 12V solar panel kit
- 12V fridge with its included 12V power cord
- 12V 100Ah LiFePO4 battery — this is the battery I used, but feel free to use a different one
- 30A ANL fuse set — a 30 amp fuse is the right size for the charge controller in the kit linked above
- Fuse cable
- 12V socket — for connecting the fridge to the battery (I’m assuming your fridge’s 12V power cord has a 12V car plug)
- Screwdriver
- Wrench or ratchet — for tightening bolts
Note: Feel free to copy this parts list as is or use the tips in the sizing sections below to pick your own.
Step 1: Understand the Wiring Diagram
Here’s the wiring diagram I’ll be using to solar power my fridge:
And here are the main things to understand about it:
- Power the fridge off the 12V battery. You can’t power a 12V fridge directly with a solar panel. Instead, you need to store the solar energy in a 12V battery and power the fridge off of that.
- Connect the battery and solar panel to a solar charge controller. You’ll damage your battery if you connect your solar panel directly to it. The battery needs to be connected to the solar panel via a solar charge controller, which regulates the voltage and current output by your solar panels to safely charge the battery.
- Protect your setup with a fuse between each connection. Safety best practices are to place a fuse on the positive wires between the battery and charge controller, and between the battery and the fridge. If you use multiple solar panels, you may also need to place inline solar fuses between the solar panels and charge controller. Refer to this video for guidance on whether or not you need to place fuses there.
- Make sure all your equipment is rated for 12 volts. If you follow this wiring diagram, make sure you’re using a 12V fridge, 12V battery, and 12V solar panel. Your charge controller should also be compatible with 12V systems.
- If you’re using a PWM charge controller with multiple solar panels, wire the solar panels in parallel.Wiring solar panels in parallel sums their currents while keeping the voltage the same. Parallel wiring is what I recommend when using a PWM charge controller. If you’re using an MPPT charge controller, I’d recommend wiring your solar panels in series.
With all that out of the way, it’s time to start building.
Step 2: Connect the Charge Controller 12V Socket to the Battery
Connect the positive battery cable (included in the solar panel kit) and fuse cable to the ANL fuse. Use a wrench or ratchet to tighten the bolts.
Now we’re ready to connect the charge controller and 12V socket to the battery.
Locate the battery terminals on the charge controller. They’ll usually be labeled with a battery icon or the word “BAT” or “BATT.”
Note: I’m using a different charge controller than the one included in the 100W kit linked above, but the steps are the same. Apologies for any confusion!
Connect the positive battery cable to the charge controller’s positive battery terminal, and the negative battery cable to the charge controller’s negative battery terminal. For most charge controllers, you need a screwdriver to do this. Open the correct charge controller terminal with your screwdriver, insert the stripped end of your battery cable, then screw the terminal shut.
At this point, your battery cables are properly fused and your charge controller is now ready to be connected to your battery. We’ll connect both the charge controller and 12V socket to the battery at the same time.
Connect the positive battery cable and positive 12V socket wire to the positive battery terminal. Once again, use a ratchet or wrench to tighten the bolt.
Connect the negative battery cable and negative 12V socket wire to the negative battery terminal. There may be a small spark when you touch the battery cable to the terminal. This is normal.
Your charge controller is now connected to your battery, so it should power on.
Confirm that your charge controller is now powered on. If it has a screen, the screen will turn on and start displaying system specs, such as battery voltage. If it doesn’t have a screen, it should have LED indicators that light up or start flashing.
Select your battery type on your charge controller following the instructions in the controller’s manual. I’m using a lithium iron phosphate (LiFePO4) battery, so I selected that option on my controller.
Your charge controller and battery are now properly connected! Here’s what my setup looked like at this point:
Step 3: Connect the Solar Panel to the Charge Controller
Locate the solar terminals on your charge controller. They’ll usually be labeled with a solar panel icon or the word “PV.” (PV stands for photovoltaic module, which is another term for a solar panel.)
Cover your solar panel(s) with a towel, or flip them face down to reduce the risk of electrical shock.
If you’re using multiple solar panels, wire your solar panels in parallel using branch connectors. For this tutorial, I’m using only the one 100W panel included in the kit. But here’s what it’d look like if you were to wire 2 panels in parallel.
Connect the positive and negative solar panel cables to the solar adapter cables (included in the kit). Once you do, make sure the exposed wire ends don’t touch.
Connect the positive solar cable to the positive solar terminal on the charge controller. Connect the negative solar cable to the negative solar terminal on the charge controller. Once again, use your screwdriver to do this.
Uncover or flip over the solar panel and place it outside in direct sunlight. My deck had a lot of shade because of nearby trees, but I found a spot that was mostly sunny.
Confirm that the solar panel is now charging the battery. If your charge controller has a screen, it may indicate charging is happening with a battery charging icon. If not, navigate to the PV current screen and you should see a positive number. If your charge controller doesn’t have a screen, it should somehow indicate charging with its LED lights.
I went to the PV current screen to confirm. It showed a current of 0.6 amps. That means my solar panel is charging my battery at a rate of 0.6 amps. (The current is low for a 100 watt solar panel due to the shading on my panel.)
All we have left to do now is connect the fridge.
Step 4: Connect the 12V Fridge to the Battery
Connect the fridge’s 12V power cord. In case you’re wondering, I’m using the BougeRV 12V 30 Quart Portable Fridge.
Plug the fridge into the 12V socket that you connected to the battery.
Confirm that your fridge is now powered on. This means your fridge is now successfully connected to your battery. At this point, you can adjust the fridge’s temperature and other settings to your liking.
That’s it! You now you have a solar powered 12V fridge. The solar panel safely charges the battery via the charge controller. And the 12V fridge runs directly off the 12V battery.
Here’s a picture of my final setup:
How Many Solar Panels Do I Need to Run a 12V Fridge?
Most people will need 100 to 200 watts of solar panels to run a 12V mini fridge. That should power your fridge long enough to last most short camping, RVing, and boating trips.
To build a solar array of this size, it’d be easiest to buy either a 100W solar panel kit or a 200W solar panel kit. If you already have a 100W solar panel kit, then you can easily add a second panel by picking up an identical solar panel and wiring it in parallel.
How did I come to this recommendation? Through a couple different tests.
First, I measured my 12V fridge’s power consumption and learned that it uses around 350 watt hours per day. Next, I also tested how much energy a 100 watt solar panel can produce, and determined that it typically ranges from 300-500 watt hours on average per day. (I used an MPPT charge controller in that test. With a PWM charge controller you can expect a little less.)
So, if I were to mount my 100 watt solar panel in a sunny spot, then, on average, it would generate around enough energy to offset my fridge’s power consumption. That should make my battery last as long as I need for most of my camping and RVing trips.
However, my 12V fridge is on the smaller end, and many other models use more power than mine does. And if you need your fridge to run for longer stretches of time, then your battery could get drained after a stretch of cloudy days. So some people will need 200 watts of solar to power a 12V fridge. For full-size 12V RV fridges, you’ll probably need even more.
Remember: These suggestions are assuming the fridge is the only thing you’re powering off the battery.
What Size Battery Do I Need to Run a 12V Fridge?
When I tested how long a 100Ah LiFePO4 battery would run a 12V fridge, it lasted for a whopping 102.5 hours.
Based on that test, I think a battery bank with 100-200 amp hours of usable capacity is a good size for running most small 12V fridges. (This is assuming you’re using your battery bank to power your fridge only.)
That size should give most people 3-4 days of runtime off the battery bank alone. Combined with a properly sized solar array, it should be enough to run your 12V fridge for 24 hours a day.
If using lithium batteries, get one to two 100Ah 12V LiFePO4 batteries or one 200Ah 12V LiFePO4 battery. In general, I recommend using lithium batteries in DIY solar power systems.
If using lead acid batteries, get two to four 100Ah 12V lead acid batteries or one to two 200Ah 12V lead acid batteries. A lead acid battery bank needs to have double the amp hours because lead acid batteries have only 50% usable capacity.
For this project, I recommend connecting multiple batteries together by wiring them in parallel. This keeps your battery bank voltage at 12 volts while expanding its amp hour capacity.
Note: There are a lot of variables at play here which may affect the right battery size for your setup. 12V fridges vary greatly in how much power they use based on their size, insulation, and whether or not they have a freezer compartment. Factors like ambient temperature and how often you open the fridge also affect power usage. If you find your battery bank dying often, that’s a good sign you should expand it.
What Size Charge Controller Do I Need?
For most people, a 30A PWM charge controller — such as the Renogy Wanderer 30A or Renogy Adventurer 30A — is a good pick if you just need to solar power a 12V fridge using the setup in this tutorial.
30A charge controllers are usually rated to handle up to 400 watts of solar power when installed in 12V systems, so you can expand your solar array later on if you find one 100W panel isn’t enough. If your solar array is larger than 400 watts or you’d rather connect your solar panels in series, I’d recommend an MPPT charge controller.
What is the output of a solar panel?
Most solar panels on the market in 2022 produce between 250 and 400 watts of power. You might come across these solar panel output numbers from your solar installation quote, which will typically include “245W”, “300W”, or “345W” next to the name of the panel. They are all referring to a solar panel’s wattage, capacity and power output.
How to calculate how much energy a solar panel produces
All solar panels are rated by the amount of DC (direct current) power they produce under standard test conditions. Solar panel output is expressed in units of watts (W) and represents the panel’s theoretical power production under ideal sunlight and temperature conditions. Wattage is calculated by multiplying volts x amps where volts represent the amount of force of the electricity and amperes (amps) refer to the aggregate amount of energy used.
Most home solar panels on the market today have power output ratings ranging from 250 to 400 watts, with higher power ratings generally considered preferable to lower power ratings. Pricing in solar is typically measured in dollars per watt (/W), and your total solar panel wattage plays a significant part in the overall cost of your solar system.
For example, if you are getting 5 hours of direct sunlight per day in a sunny state like California you can calculate your solar panel output this way: 5 hours x 290 watts (an example wattage of a premium solar panel) = 1,450 watts-hours, or roughly 1.5 kilowatt-hours (kWh). Thus, the output for each solar panel in your array would produce around 500-550 kWh of energy per year.
What factors determine solar panel output?
Before calculating the amount of energy a solar panel can produce, it’s important to understand the two key factors that determine its power output: cell efficiency and solar panel size.
Let’s assess each factor separately to understand them a bit better.
Solar panel efficiency
Of all the metrics to look at when shopping for solar panels, efficiency is one of the most important. The higher a panel’s efficiency is, the more power it can produce. Today, most silicon-based solar cells can convert between 18 and 22 percent of the sunlight that hits them into usable solar energy, which has led to panels exceeding 400 watts of power. Higher efficiency = more energy, so high-efficiency solar panels generally will produce more electricity for your home. As of 2022, the National Renewable Energy Laboratory (NREL) developed the most efficient solar cell to date at 39.5 percent effi cie ncy.
Number of solar cells and solar panel size
To make things easy, we can divide solar panels into two size groups: 60-cell solar panels and 72-cell solar panels. Usually, 60-cell solar panels are about 5.4 feet tall by 3.25 feet wide and have an output of about 270 to 300 watts. On the other hand, 72-cell solar panels are larger because they have an extra row of cells, and their average output is somewhere between 350 to 400 watts. 72-cell panels are usually used on larger buildings and in commercial solar projects, not on residential homes.
Environmental factors: shading, orientation, and hours of sunlight
Solar panel efficiency and the number/size of solar cells in a solar panel are factors that directly impact the rated power of a solar panel. In the real world, there are a few more things that impact how much power a panel will actually produce:
Shading of your solar panels will lead to lower production. Solar panel wattage ratings do not take into account the lowered output of a panel when there’s shade blocking the sun.
Orientation of your solar panels also impacts production in a way that a panel’s output rating doesn’t capture. Ideally, your panels will be angled directly towards the sun. In practice, roof planes are almost never perfectly angled for maximum production.
Hours of sunlight simply refer to the amount of time per day (or year) that your panels are exposed to sunlight. The more hours in the sun, the higher your actual output will be.
How much energy will an entire solar panel system produce?
Knowing how much energy a single solar panel produces is all well and good, but more importantly, how much solar power can your roof generate? Let’s do the math below:
Take our example above, where you’re getting an average of five hours of direct sunlight per day (an average amount of sunlight for most areas of California) and using solar panels rated at 290 W. Let’s say you install 30 of those premium solar panels on your roof–that nets you an 8,700 watt, or 8.7 kW solar panel system, near the average system size purchased on the EnergySage Marketplace. Multiply the five direct sunlight hours we estimated above by 8.7 kW, and we get approximately 43.5 kWh of electricity produced per day. And for one final conversion, if we multiply 43.5 by 365 days in a year, we get approximately 15,800 kWh of electricity produced in a full calendar year from a rooftop array of 30 premium, 290 W solar panels. Considering that the yearly average for electrical power is around 10,600 kWh in the U.S., that’s probably more than enough to power your home on solar.
Solar panel output and cost
The output of a solar panel has a significant impact on its cost. This cost can vary based on where you live and what your needs are, but with data from the EnergySage Marketplace, we can get an idea of how much it could cost on average for 3kW, 4kW, 5kW, 6kW, 7kW, 8 kW, and 10kW solar systems. To find out how much this could be for you, simply find the average cost per watt in your area and multiply that by the output of the solar panel you have in mind.
Solar panel output by product
With so many solar panel manufacturers out there, panel output varies significantly between brands and products. In 2022, these are the top six solar panel brands in the U.S. ranked by their maximum power output panel:
- First Solar (460 W)
- LONGi (455 W)
- REC (450 W)
- SunPower (435 W)
- Q CELLS (430 W)
- Solaria (430 W)
The table below presents a view of power output from many manufacturers supplying solar panels to the U.S. market. Because panel manufacturers often produce more than one line of solar panel models, the power output of most companies has a significant range. The table below lists the solar panels’ minimum, maximum, and average power outputs within each manufacturer’s portfolio.
Electricity output (in Watts) of solar panel manufacturers
| Amerisolar | 240 | 330 | 285 |
| Astronergy | 350 | 370 | 360 |
| Axitec | 250 | 385 | 302 |
| BenQ Solar (AUO) | 250 | 295 | 277 |
| Boviet Solar | 320 | 340 | 330 |
| Canadian Solar | 225 | 410 | 320 |
| CentroSolar | 250 | 320 | 278 |
| CertainTeed Solar | 70 | 400 | 308 |
| ET Solar | 255 | 370 | 306 |
| First Solar | 420 | 460 | 440 |
| GCL | 310 | 330 | 320 |
| Grape Solar | 160 | 285 | 237 |
| Green Brilliance | 230 | 300 | 266 |
| Hansol | 250 | 360 | 304 |
| Hanwha | 365 | 385 | 375 |
| Heliene | 250 | 370 | 306 |
| JA Solar | 260 | 410 | 329 |
| JinkoSolar | 315 | 410 | 367 |
| Kyocera | 260 | 330 | 295 |
| LG | 315 | 415 | 365 |
| LONGi | 305 | 455 | 387 |
| Mission Solar Energy | 300 | 390 | 334 |
| Mitsubishi Electric | 270 | 280 | 275 |
| Neo Solar Power | 310 | 330 | 320 |
| Panasonic | 320 | 370 | 340 |
| Peimar | 310 | 310 | 310 |
| Peimar Group | 270 | 330 | 301 |
| Phono Solar | 260 | 350 | 294 |
| QCELLS | 285 | 430 | 358 |
| REC | 275 | 450 | 347 |
| RECOM | 265 | 370 | 308 |
| Recom Solar | 310 | 350 | 330 |
| ReneSola | 245 | 320 | 277 |
| Renogy Solar | 250 | 300 | 268 |
| RGS Energy | 55 | 60 | 58 |
| Risen | 270 | 390 | 329 |
| S-Energy | 255 | 385 | 334 |
| Seraphim | 255 | 340 | 294 |
| Silfab | 300 | 390 | 335 |
| Solaria | 350 | 430 | 375 |
| Solartech Universal | 310 | 325 | 318 |
| SunPower | 320 | 435 | 355 |
| SunSpark Technology | 310 | 310 | 310 |
| Talesun | 275 | 415 | 365 |
| Talesun Solar Co. | 400 | 400 | 400 |
| Trina | 265 | 415 | 337 |
| Trina Solar Energy | 260 | 320 | 288 |
| Upsolar | 270 | 365 | 311 |
| Vikram Solar | 320 | 340 | 330 |
| Winaico | 325 | 340 | 332 |
Why does solar panel output matter?
Power output is an important metric for your home or commercial solar panel system. When you buy or install a solar photovoltaic (PV) energy system, the price you pay is typically based on the solar panel output of your system (expressed in watts or kilowatts).
How do size and quantity impact output?
Power output on its own is not a complete indicator of a panel’s quality and performance characteristics. Some panels’ high power output rating is due to their larger physical size rather than their higher efficiency or technological superiority.
For example, if two solar panels both have 15 percent efficiency ratings, but one has a power output rating of 250 watts, and the other is rated at 300 watts, it means that the 300-watt panel is about 20 percent physically larger than the 250-watt panel. That’s why EnergySage and other industry experts view panel efficiency as being a more indicative criterion of solar panel performance strength than solar capacity alone.
In practical terms, a solar panel system with a total rated capacity of 5kW (kilowatts) could be made up of either 20 250-Watt panels or 16 300-Watt panels. Both systems will generate the same amount of power in the same geographic location. Though a 5kW system may produce 6,000 kilowatt-hours (kWh) of electricity every year in Boston, that same system will produce 8,000 kWh yearly in Los Angeles because of the amount of sun each location gets each year.
The effect materials have on output
The electricity generated by a solar PV system is governed by its rated power output, but it’s also dependent on other factors such as panel efficiency and temperature sensitivity, as well as the degree of shading that the system experiences and the tilt angle and azimuth of the roof on which it’s installed. As a general rule of thumb, it makes prudent financial sense to install a solar system with as much power output as you can afford (or that your roof will accommodate). That will ensure you maximize your savings and speed up the payback period of your solar energy system.
Find out more about average for solar across the country for 3kW, 4kW, 5kW, 6kW, 7kW, 8 kW, and 10kW solar systems. The EnergySage Marketplace makes it easy for you to compare your savings from solar panels with various power output ratings.
Common questions about how much energy a solar panel produces
Because few people own just one solar panel, we talk more about the system output than individual solar panel output. Here are some of the questions we are frequently asked surrounding how much energy solar panels, and solar panel systems as a whole, generate.
This depends on weather conditions, how much sunlight a location gets, and solar panel output. It would take about 27 solar panels to produce that much electricity in ideal conditions with the average solar panel.
A panel of this size would produce between roughly 1.2kW to 2.5kW per day. Solar panel output and the amount of sunlight available will impact how much energy it produces.
If exposed to the sun at least four hours a day, a system of this size can produce up to 20kWh per day.
The average solar panel produces from 170 to 350 watts every hour, depending on the region and weather conditions. This works out to about 0.17 kWh to 0.35 kWh per solar panel.
Explore your solar options today with EnergySage
If you’re in the early stage of shopping for solar and would just like a ballpark estimate for an installation, try our Solar Calculator, which offers upfront cost and long-term savings estimates based on your location and roof type. For those looking to get and compare quotes from local contractors today, check out the EnergySage Marketplace.
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