September 19, 2023

Can Solar Panels Power a Whole House?

How much it will cost to install your solar system

The price of solar panel installation depends on many factors, but on average, you should expect to pay $18,000–$20,000 for a new solar system. However, this price doesn’t factor in government incentives like the federal tax credit which can significantly reduce the total cost of your system and help it pay itself off quicker.

Also, your actual price will probably look a little different from these averages since the price of a solar system is determined by how many panels it has, what state it’s installed in, and the type of panels it uses. Additionally, getting even one solar battery can increase the price by several thousand dollars.

Because of this variability, the best way to know what you’ll actually pay for your solar electricity system is to get a quote from a solar company.

Can you power your entire home with solar panels?

The answer to this question is more complex than you might expect. In short, solar panels can provide all the energy your home needs when the sun is out as you install enough of them.

Unfortunately, though, solar panels don't generate energy at night, and they don't produce as much electricity on cloudy days. So when the sun isn't shining, solar panels cannot run your home—at least not on their own.

Relying on solar batteries in dark times

The only way you can run your home entirely on solar energy is by installing a solar storage system. When you have a solar battery, your panels send the excess energy they produce during the day to the battery for storage. Then, when the sun goes down, your system pulls the energy from the battery to power your home throughout the night.

Adding energy storage will ensure you're using all of the solar energy your panels generate, so if your primary reason for going solar is to become more self-sufficient and reduce your carbon footprint, then energy storage is the best way to do it.

However, it's not the most cost-effective option. Solar batteries typically cost a minimum of $12,000 to install, and you may need to install more than one to meet all of your energy needs. If your primary motivator for going solar is to save money, you can probably skip the battery, especially if your state requires net metering.

Can solar panels eliminate your electricity bill?

If your local utility company offers net metering, your solar panels can eliminate most—if not all—of your monthly electricity bills even if you don't install a solar battery.

When you install a grid-tied solar system, you will still be connected to the local power grid. As we mentioned earlier, solar panels make the most electricity in the middle of the day, which also happens to be when your home uses the least electricity. This means your solar panels will probably be making more energy than your home needs.

When this happens, the excess energy is sent to the grid and is used to power other buildings. This reduces strain on the power grid and helps the electric company conserve fossil fuels. And don't worry, all your solar power gets used by your home first, so you get first dibs on the electricity your panels create. Only the electricity you don't use goes to the grid.

The best part of the deal is that—if your utility company offers net metering—you will get credited all or part of the price for every kilowatt-hour of solar energy you send to the grid. If you export one kWh of electricity, you can then pull a kWh of energy from the grid later without paying full price. If your utility company offers full-retail net metering, you'll get that kWh for free.

So, even though your solar panels can’t directly power your entire house at all times, they can still reduce your monthly electric bills to zero through net metering. Unfortunately, though, full-retail net metering isn’t available everywhere. To find out if your state is among those that require companies to offer consumers full-retail net metering, check our list.

How many solar panels do you need to power your whole home?

Most American households need somewhere between 16 and 20 solar panels to cover the costs of their energy usage. However, this number is simply based on the average residential electricity consumption in America.

The perfect number of solar panels for your home will depend on how much energy your household actually uses, the power rating for each panel you install, and how efficiently the panels can run in your area.

This step-by-step guide can help you determine how many solar panels you need to power your entire home.

Step 1: Check your electricity usage

First, look over your power bills to learn how much electricity your home consumes on average every month. Power usage fluctuates with the seasons, so look at your monthly bills from one entire year, add the number of kilowatt-hours you used each month together, and divide the total by 12 to get a holistic average.

Step 2: Find out how many peak sun hours your area gets

Because the actual output of a solar panel is partially determined by how much direct sunlight it receives every day, the next step is finding out how many peak sun hours your area sees every day.

We can help you with this part. We’ve listed the number of peak sun hours each state receives on average, so you can quickly discover how many you can rely on by checking our list.

Step 3: Determine solar panel wattage

Next, check the wattage of any solar panels you might purchase to determine the amount of electricity they can output. Not all panels produce the same amounts of energy, and their output is represented by their wattage. The lower the power rating of your panels, the more of them you’ll need to power your home.

When talking about the energy output of an entire solar panel system, you combine the wattage of all its panels, and this means talking in terms of thousands of watts. For simplicity, you can shorten the numbers by measuring the output in kilowatts (kW) instead of watts. 1,000 watts is equal to one kilowatt, so 16 solar panels that each have a rating of 300 watts have a collective rating of 4.8 kW.

Under perfect conditions, a 4.8 kW solar power system can create 4.8 kWh of energy in a single hour. In the real world, the system will produce less energy than this.

Step 4: Calculate how many solar panels you need

Now it’s time to do some math.

First, let’s say your household consumes the U.S. average of 893 kWh every month. Then, let’s say your home’s in Florida, a state that gets 4 peak sun hours daily. Multiply this number by 30 to determine how many peak sun hours your home sees every month: 120. So, a 1 kW solar system on your roof would produce roughly 120 kWh of electricity every month.

Next, divide your home’s energy consumption by 120 kWh to determine how many kW of solar panels you should install to get all the electricity your home needs. 893 kWh divided by 120 kWh is 7.44 kW, so you’d need a 7.5 kW system to cover your energy consumption.

For the final step, let’s say the solar panels you’re likely to purchase are rated for 400 watts. Divide 7,500 by 400 to determine how many of those panels your system will require. The answer is 18.75, so we’ll round up and say that you’d need 19 of those solar panels for your home.

You can now use this same formula to determine how many solar panels you’d need to cover your entire home’s energy consumption.

Powering your whole home with solar panels

While your solar panels can’t power your whole house at all times, a good net metering program can ensure they always cover your electricity bills. However, if you don’t have net metering in your area, solar electricity probably isn’t financially viable for you. At least not until installations become a bit cheaper. Solar batteries can reduce your need for expensive grid electricity, but they also significantly increase the overall cost of your system.

That said, if you've got the money and your primary motive is reducing your environmental impact as much as you can, then solar panels paired with batteries are a great way to power your home.

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