From a small 50 watt portable solar panel to keep your devices charged to powerful 300 watt panels to mount on the roof of your tiny home or cabin, there’s a solar panel for everyone. How many panels do you need to keep things charged up in your home? Is it possible to run a refrigerator on a solar panel? With some simple calculations it’s easy to ensure your solar installation will meet your energy needs.
How do solar panels work
First let’s talk about the basics of how solar energy is generated. Photovoltaic solar panels are made up of many solar cells made of silicon. When sunlight hits the panels, they create an electric current. Panels have both a positive and a negative layer, which creates an electric field.
The current collected by solar panels then feeds into a charge controller, which controls how much current goes to a battery. Charge controllers prevent batteries from being overcharged. They also have the ability to shut down a system if the energy stored dips below 50%. Batteries store and produce DC power. In order to use AC appliances, such as microwaves, laptops, and phone chargers, an inverter is used to change the power from DC into AC power.
In a home, solar panels are connected to a grid inverter, which is then connected to the existing electrical network in your house. In an RV, van, or boat, you can choose from a range of different inverters based on your specific energy needs.
How many solar panels do I need to run a refrigerator?
The average refrigerator takes about three or four average solar panels to run. The average refrigerator found in the United States uses approximately 57 kWh per month while the average freezer uses 58 kWh. Adding those together brings a combined total of 115 kWh.
A 100 watt panel receiving at least 8 hours of sunlight per day will produce almost 1 kilowatt-hours per day or 30 kWh per month. Divide that usage of the refrigerator (115kWh) by 30 kWh per month and you get 3.8 solar panels. This means you’ll need four panels to keep this refrigerator running.
What can you run with a 300 watt solar panel?
A 300 watt panel that receives 8 hours of sunlight per day will produce almost 2.5 kilowatt-hours per day. If we multiply this by 365 days per year, we get a solar output of about 900 kilowatt-hours annually. In short, each panel will provide 900 kilowatt-hours each year.
Considering all of the different scenarios, there is still a long list of appliances and devices that can run effectively with 300-watt solar panels, including laptops, LED lights, stereos, and TV’s.
To get an accurate calculation of what you can and cannot power with a single 300 watt solar panel, you’ll need to compare the output per day or month (so 2.5 kWh/day for the solar panel) with the needs of an appliance (3.8kWh/day for a refrigerator). In this example, a 300 watt solar panel would not be enough to power that refrigerator.
What can a 500 watt solar panel run?
Let’s assume that each panel gets around 8 hours of sunlight per day on your rooftop. A 500 watt panel receiving 8 hours of sunlight per day will produce about 4 kilowatt-hours per day. If we multiply this by 365 days per year, we get a solar output of about 1460 kilowatt-hours annually. In short, each panel will provide 1460 kilowatt-hours each year.
Buying a combination of these larger panels will help you meet the need of more energy-hungry appliances, such as refrigerators, stoves, hot water heaters, and dryers.
How many amps does a 300w 12v solar panel produce?
To calculate amps, remember the equation amps x volts = watts. In this example, amps x 12 volts = 300 watts. Using this, we learn that this panel will produce 25 amps.
How many solar panels do I need to go off-grid?
For the cases of this example, let’s say we have some 300 watt solar panels, and you’re looking to provide power for your home. You don’t have access to the grid and installing off-grid solar on your home is your best option for meeting your energy needs.
Let’s assume that each panel gets around 8 hours of sunlight per day on your rooftop. A 300 watt panel receiving 8 hours of sunlight per day will produce almost 2.5 kilowatt-hours per day. If we multiply this by 365 days per year, we get a solar output of about 900 kilowatt-hours annually. In short, each panel will provide 900 kilowatt-hours each year.
How much energy does your home use? Most data suggests that a typical American home (2,000 square feet home) consumes approximately 11,000 kilowatt-hours annually. So, when we divide our total consumption by the expected output of one solar panel, we see that roughly thirteen solar panels of this size would be enough to power a home of that size. If you have a smaller home or are powering an RV, your energy needs will be much lower, and you’ll need fewer panels.
How many solar panels do I need to power my air conditioner?
Central air conditioners take up a lot of energy and use about 3,5000 watts, or 3.5 kWh, for every hour that they are in operation. That means each solar panel will be able to power your A/C for about 8.5 hours. However, if you run your A/C for 6 hours per day, that means you would need more than 21 100 watt solar panels to cover 180 hours per month of use. If you have a smaller solar installation, you’ll want to limit your AC use or forgo it altogether.
How many solar panels does it take to charge a 100ah battery?
Again we use the same calculation dividing power in watts by the voltage in volts to find amps.Charging your battery at 12 volts and 20 amps will take five hours to charge a 100 amp hour battery. By multiplying 20 amps by 12 volts, 240 watts is how big of a panel you would need, so we’d recommend using a 300w solar panel or 3 100 watt solar panel
Do solar panels work in cloudy areas?
Even if you’re in a cloudy area, solar panels produce around 25 percent as much energy as they would on a sunny one. Also, despite popular belief, solar panels actually operate more efficiently in colder climates than in warmer ones.
However, if you know you’re going to be mostly travelling or living in mostly cloudy areas, it’s important to take that into consideration when considering how much power your system will be able to generate and if that investment in the system is worth it. Refer to the Renogy solar calculator to get a more accurate estimate of what size system you need.
What do I do at night when my panels aren’t producing power?
If you are off-grid, your panels will have stored excess energy in your battery bank for you to tap into at night when your panels are not collecting power.
If you are on-grid, you can often take advantage of a utility billing mechanism called net metering. This is when excess electricity your panels are produced during the day are fed into the grid and credited to your account. Then, at night or when it’s cloudy, you can utilize those credits.
How do I know how many panels I need?
To determine what size system will best fit your needs, make a list of all the appliances and devices you plan on running. The main appliances to take into consideration when addressing energy needs may include a TV, lighting, water pump, laptop, fans, microwave, and refrigerator. We recommend using the Renogy solar panel calculator to help design your system and calculate your needs.
The solar sizing calculator allows you to input information about your lifestyle to help you decide on your solar panel requirements. You’ll just need to know what total watts your electronics will consume, how long you plan on running devices, your charge controller efficiency, and average sun hours per day. The solar panel calculator will then be able to tell you the minimum and recommended system size, as well as the recommended battery output.
Renogy has a variety of different sized solar panels and solar kits available for purchase. Taking the time to do some math on the capacity of your solar panels and the needs of your household appliances and devices will ensure you have an effective solar installation that meets all your solar needs.