How Much Power Does a Solar Panel Produce?How Much Power Does a Solar Panel Produce?

As a homeowner, you want to find new and creative ways of lowering your utility bills. When it comes to renewable energy, one popular option is to install residential solar panels. One residential solar panel generates 250 watts per hour on average. The range is 170-350 watts per hour.

Depending on the area and climate in which you live, these panels can significantly reduce your electricity bill.

That said, there are many questions surrounding home solar panels, including how they work, how much they cost, and how many you need to power various devices.

Fortunately, we have compiled all this information into this handy guide. This solar panel article will show you how to calculate the number of solar panels you need and your total installed cost. Then, you can compare that cost to your current electricity bills to determine your ROI.

Here is what you need to know.

Solar Panel Sizes and Wattage
When shopping for solar panels, the two primary components to pay attention to are size and wattage. When it comes to solar panels for buildings, there are three standard sizes available, based on the number of cells they have. If you're unfamiliar with how solar power works, each panel has a set number of photovoltaic solar cells that capture sunlight and convert it into electricity. The three options include:

  • Residential Solar Panels = 60 Cells, 39 inches wide, 66 inches long
  • Commercial Solar Panels = 72 cells, 39 inches wide, 77 inches long
  • Extra Large Panels = 96 cells, 41.5 inches wide, 62.6 inches long

As you can imagine, larger panels are not meant for residential properties, so you will need to install 60-cell units onto your roof. Most solar panels are between 1.4 inches and 1.8 inches thick, although 1.8 inches is becoming the standard since that allows more room for the cells to capture sunlight.

Additionally, you can find a wide array of small solar panels for RVs and other smaller structures. Because there is not a US universal standard for these units, the size varies greatly. On average, these panels range from 21 to 26 inches wide, 26 to 58 inches long, and 0.1 to 1.5 inches thick. The thinner models are flexible, so you can deploy them and roll them back up when not in use, like a solar magic carpet.

When it comes to wattage, the exact output depends on panel efficiency. Not all manufacturers are the same, so some units can be far more energy-efficient than others. A single panel can produce up to 150 watts per hour on the low end, while a high-end model can deliver up to 370 watts. That said, most panels generate 250 watts per hour on average.

How Much Are Solar Panels for a House?
Oddly enough, when using a solar installer to put panels on your home, you will be paying per watt, not per panel. Rather than pricing the installation as the number of 60-cell units, you will have to determine your total power needs.

Follow these two steps to figure out what your costs could be:

  • Measure Your Current Power Usage. Your utility company can give you an average in kilowatt-hours for the last year to provide you with a reasonable estimate of the amount of electricity you use.
  • Figure Out How Much Sun-Facing Space You Have. If you own a small house, you are limited in how many square feet you can use. Also, pay attention to any roof features that could prevent installation, such as windows, skylights, or chimneys.

If you live in a sunny part of the country, your solar panels will generate far more power than if you live in a cloudy or rainy climate. However, even if you have fewer daily sun hours, you could still potentially save money annually. The sun still delivers rays to solar panels in the winter. 

Installation costs can vary depending on where you are in the United States as well. You can find out more about solar costs here.

The average cost of solar panels is $3 to $5 per watt. So, if you install a 3,000-Watt system, you could expect to pay between $9,000 and $15,000 for the whole thing.

Fortunately, there is a federal solar tax credit for solar installation. In 2021, that credit is 22 percent. That means that if your bill is $10,000, you could receive $2,200 in tax credits. Unfortunately, this credit program may not continue past this year, so now is the time to take advantage.

How to Use a Solar Calculator
When searching online for a solar calculator, you will notice that there are several options.

  1. First, you can calculate your annual savings by switching to solar power. This solar calculator from Energy Sage asks for your specific address to determine the average hours of sunlight your home receives, as well as how well your solar system can receive energy from the sun.
  2. Second, you can calculate the energy output from various sizes of solar panel systems. This solar calculator from the National Energy Renewable Laboratory is a bit complex, but it can give an idea of the average daily electricity you can expect. You might need to get specific parameters from your solar company to use it effectively.
  3. Finally, you can use a solar calculator to determine the number of panels you need. However, you can do this calculation yourself, as we will discuss in the next sections. All you must do is calculate the average kWh usage and divide that by the average output for each solar panel.

Overall, solar calculators can come in handy to give you an idea of what to expect before installing a new system. Typically, these panels will pay for themselves in about 10 or 12 years, depending on your location, electricity rates, and your installation size.

How Many kWh Does a House Use Per Day?
According to the U.S. Energy Information Association, the average home uses around 877 kWh per month. To determine the usage by day, we divide that by 30 to get a total of 29.33 kWh per day.

To get an exact total for your home, you want to ask your utility company for your total kWh. If they can't provide a monthly average, you can do the same calculation. However, some companies measure your net metering by year, so you will want to use that total and divide by 12 to find the average kWh per month.

How Many Solar Panels to Power a Home?
As we mentioned, most panels produce around 250 watts per hour. When converting, 250 watts equals 1kWh. Depending on your climate, you could get four or five hours of direct sunlight on your roof, which would yield between one kilowatt and 1.25 kilowatts in a single day.

Based on our average electricity usage calculation above, most homes would need to produce almost 30 kWh daily. Since the number of sun hours can vary, it is best to be conservative with your estimates. Even if your solar panels can deliver 1.25 or 1.5 kWh on a sunny day, you should base your forecasts on a single kilowatt-hour to be safe.

Using this data, one can say that the average home would need at least 30 solar panels to generate 100 percent of its energy. That assumes you need one kilowatt each day (30 KW per month), and each panel will generate one kilowatt per month. You can do the same calculations based on your exact energy usage.

Based on the installed price of $3-$5 per watt, your 30-panel system would cost $9,000 - $15,000.

How Many Solar Panels to Power a Home?Solar Panel Systems FAQs

Here are some answers about the energy output for these devices so you can understand what you can do with your new solar panels.

  • How Much Power Does a 50-Watt Solar Panel Produce?
    At 50 watts per hour, this panel could produce up to 400 watts per day, assuming a full eight hours of direct sunlight. On a cloudy day, the output may be 200 watts or less.
  • How Much Power Does a 1000-Watt Solar Panel Produce?
    Unfortunately, solar panels with this kind of electricity production do not exist for residential properties. However, based on eight hours of sunlight, a 1000-watt panel could deliver eight kWh of energy per day.
  • How Much Power Does a 300-Watt Solar Panel Produce?
    As we mentioned, most panels that generate this kind of output will yield anywhere from one kWh to 1.5 kWh per day, depending on the amount of sunlight. If you get eight hours of sun, you could receive up to 2.4 kWh from a single 300-watt unit.

Here are some general questions related to solar panels and their electricity output.

  • How Much Power Does a Solar Panel Produce Per Hour?
    When looking at different solar panels, the wattage rating tells you how much energy the unit produces in an hour. So, a 250-watt model can create that much electricity hourly.
  • How Much Power Does a Solar Panel Produce Per Day?
    To calculate this, you would take the wattage rating of the panel and multiply it by the total hours of direct sunlight it gets. So, if you have a 300-watt panel and get an average of five sun hours per day, its energy output would be 1.5 kWh.
  • Can a 100-Watt Solar Panel Run a Refrigerator?
    The short answer is no because your fridge stays running 24/7. Not only that, but most refrigerators use more than 100 watts per hour, with many models using close to 200 watts. That said, if you have a mini-fridge and only use it during the daytime, a 100-watt panel could potentially keep it running.

What Solar Panel Wattage Size Do I Need to Run a Window Air Conditioner?
Since air conditioning can be a huge power drain during the summer, it may be worth installing a solar system to save on your cooling bills. Our example below shows that you need three residential solar panels to run a window air conditioner for 8 hours a day.

That said, there are a few variables to figure out before you can determine how many solar panels you would need to cover this one appliance's energy needs.

  • BTU Power Ratings. Although BTU stands for British Thermal Unit, air conditioners measure their cooling capacity in BTUs. The more it has, the more electricity it uses. Here is a handy solar calculator to determine the exact wattage of your appliance. For example, a 5,000 BTU conditioner uses 500 watts of electricity.
  • Daily Usage. Are you running your air conditioner at all hours of the day, or just when it is hottest outside? The total hours you have it running will affect your energy needs.
  • Hours of Sunlight. How many hours does the sun hit your solar panels on average?

For example, say that you have a 5,000 BTU air conditioner and run it for an average of 8 hours a day. The AC's total energy usage would be four kWh (500 x 8 = 4,000 watts/4 kW). Additionally, let us say that you have 300-watt rooftop solar panels that receive an average of six sun hours per day. At that rate, each panel would produce 1.8 kWh daily.

So, all you do is divide four kWh by 1.8, which is 2.2. Since solar panels do not come in fractional sizes, you would need three of them to ensure that you can operate your air conditioner without fail. You will need nine if you run your AC 24-hours a day. Sadly, if you live in an apartment building, you most likely cannot fit three or nine solar panels anywhere outside.

Are Solar Panels Covered by Home Insurance?
Since installing a new solar system is a significant investment, you want to be sure that you can protect it. Fortunately, most homeowners insurance policies cover solar panels because they are permanent installations, much like a patio or fixed awning. Your insurance company may offer solar panel insurance coverage, but it should not be necessary.

That said, you should talk to your insurance agent to see whether the panels will increase the repair costs of your home. If so, you might want to increase your coverage limit to ensure that you do not have to pay out of pocket if a terrible disaster strikes. Be sure to calculate your new insurance premium as well so that there are no surprises.

Thankfully, since you will be fixing the panels to your home's main structure, there should not be any claim sub-limits to worry about. For example, separate structures like a pool house or gazebo only qualify for up to 10 percent of your total coverage amount.

Also, because they are attached to your home, they come with RCV coverage. That means if you file a claim, your insurer will pay the retail price to replace the panel(s). Remember, though, that your deductible applies.

Get a Home Insurance Quote with Solar Panel Coverage
Solar panels are an investment in your home, and you need to protect them adequately. We make it easy to compare home insurance rates and policies to ensure that disasters will not sabotage your energy-saving system. Click the quote button below to find out more.

Hope that helps!

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