How many solar panels to run a house: 1500, 2500 and 3000 sq. ft cost?

Looking for a way to reduce electricity bills and also contribute to the reduction of global warming for your family? Solar installation is an imperative addition to the future of American homes. It is expected that by 2024, 2.5% of all American homes will have a solar installation. According to the Solar Energy Industries Association, the USA has already surpassed the whopping number of 2 million solar PV installations which is a great sign of growth in the renewable energy sector.

If you’re thinking of getting your hands on this nifty little product, keep reading to find out how many solar panels to run a house: 1500, 2500, and 3000 sq. Ft cost? But first, let’s start with the basics.

How do they work?

What goes behind the working of those shimmery panels that eventually result in the production of electric current? Well, the panel itself contains a layer of silicon, a metal frame, and wiring, all of which is encompassed within a glass casing with film. This equipment comes together to make a semi-conductor. The cells within these are called photovoltaic cells.

This is how it goes down: the sunlight hits the panels, the cells are charged and electrons are released from the semiconductor wafer and the motion around them creates an electric current.

Now that the electricity is ready, it needs a way to power the home you live in. But your house operates on Alternative current (AC) and not the Direct current(DC) produced by the panel. This is why an inverter is brought in to convert the DC to AC and start powering your needs.

They can be a great power source if your family lives near the beach!

What happens to surplus energy?

A net meter records usage in your home. There may be rainy days where solar energy is low and days when you’re not home but enough solar energy is generated to run your home on regular days. The meter will track this energy usage coming from and to your place. This makes it easy for the utility company to give you credits for days you may be away and surplus energy flows into the grid.

How long do they last?

Since they have started booming, the innovation of solar panels is noticed to have lasted about 25-30 years before it needs replacing again. However, some systems are known to last about 50 years too! You might be surprised at these figures but it is because solar panels require little to no maintenance that they can last almost the life of an average human.

Do they lose efficiency over time?

Yes, most solar panel systems degrade at about 1% per year. That means after 10 years they would have lost about 10% of efficiency. By the time, the lifespan of a solar panel ends, they would still be working at about 75% efficiency which is not bad at all!

alternative energy source

How many do you need?

Naturally, the number of solar panels needed increases with the size of your house. But there are also other factors to consider. Keep reading to find out all the pointers:

  • Sunlight hours: Depending on the location of your home, peak and brightest sunlight hours will change. You will have to keep track of the light in your home and calculate it according to the voltage used by your family. Your hourly usage is multiplied by the sunlight hours at peak time. The resultant figure will be divided by the wattage of the panel.
  • Your usage: You will have to keep track of your usage to determine how many you will end up with. This can be done easily by taking a look at your utility bill and checking the kilowatt-hours (KWH). Some families will draw more energy due to several factors. For example, hot weather forces air conditioners to be used more frequently and hence a higher bill. Ones that have a workshop or a small business are likely to have more appliances that will need even more current.
  • The size of the property: It’s natural that with a bigger house, you’ll require more plug points and thus more current to power them. Therefore, the number is likely to increase with the square foot area. Let’s take a look at the area-wise allotment of panels below.

1500 square foot

An average American home is approximately this size and thus we can get a rough idea of how many panels you require. On average, a house this size generates a bill of around $100 per month. For usage of this site, you would require somewhere between 15 -20 panels. The exact figure can be determined when you know the other factors like usage, sunlight hours, and the wattage of each brand.

solar panels on a roof

2500 square foot

A house of this size means even more electricity is needed. Therefore it’s more common for a house this size to use both generic and solar-generated electricity. A place of 2500 sq, feet generates approximately 11,775kWh per year. This figure divided by an average wattage generated by most brands’ panels comes down to around 37 panels. That’s of course only if you choose to rely on solar alone and no other source of energy. The number will decrease if you plan to switch up to regular utility company power in the winters for example.

3000 square foot

A house of this size will generate almost 14000 kWh per year. This usage generates around 44 panels on the roof if you only want solar energy to run in the house. Keep reading further below to find out the cost of these installations.

How many kilowatts does my family use?

By now you’re probably convinced about the idea of installing solar in your home to save on bills and aid climate change. So you’re probably wondering, how many solar panels does your home need? And to answer this, you need to know how much electricity your house uses. Take a look at your past bills and divide the monthly average by thirty or the yearly average in kWh by 365. The resultant factor should be divided again by 24 to determine your hourly average electricity usage. Your answer will be in kWh.

Alternatively, you can also go the detailed route and choose to take note of the wattage of each device that you own and use. You can find the wattage on each device and multiply it by the hours it’s plugged in to get the kilowatt requirements.

For instance, 100 watts for a device plugged in for 10 hours will equal 1000 watt-hours or 1kWh.

In this manner, you can calculate all the device hours and find the charge per kWh to find the expense of your home approximately.

solar panels at night


Let’s get into the details of what type you might install and how the types differ from each other. The basic three types of solar panels are listed below.

1. Thin film

This type is made from many types of materials but the most commonly used is cadmium telluride (CdTe). This layer of CdTe is placed between transparent layers that help capture sunlight and even has a glass layer on top for protection. The advantage that this type offers over others is its flexibility and portability. However, they offer lower performance than their supplements.

2. Monocrystalline

These are made from silicon sheets and are known to be the purest form of solar panels. Since the silicon is so pure, it is responsible for the highest efficiency in all types. The newest ones go as high as 20% in terms of efficiency. They also last the longest and occupy the least amount of space. This also means they cost the highest and you’re going to have to dig up some savings to invest in this one.

3. Polycrystalline

This type has a blue speckled look and has squares. They are made from melting raw silicon and don’t have a long manufacturing process like monocrystalline which makes them cheaper too. For this reason, it also has a lower efficiency rate and shorter lifespan. Their efficiency is about 15% and they can be quite affected by high temperatures which isn’t the case in monocrystalline. Polycrystalline also occupies more space than previous types. However, power outputs are usually the same when it comes to both.

How many solar panels does it take to run a house?

Like we mentioned before, the number of solar panels you need depends on 2-3 factors. An average home is about 1500 square feet in the US. If we run by the average scenario, a home of this size usually clocks about $100 in their utility bill. That means you would need around 15-18 panels to cover a home of this size for solar installation. This figure will differ however based on your peak sunlight hours, location, and hourly usage. For a bigger house, the panel number just keeps increasing.

Solar being installed

How much do solar panels cost for 1500, 2500, and 3000 square foot houses?

Now that we’ve seen the number needed, we can look at the money factor.

1500 sq. foot cost

Since the use of solar began initially, the prices of their usage have gone down significantly. A typical one can cost between 50 to 70 cents per watt. A 350W model would then be anywhere between $175 and $245. Since we mentioned before that a house of this size will require about 15- 18 panels, the comes down to $2625 – $3675.

2500 sq. foot cost

For a home of this size, you would require anywhere between 17 to 25 premium panels that are high efficiency. A 2500 size home would generate around 11,775 kWh per year. If you’re using budget ones, the number needed would go up. According to the calculations we just performed above, your cost would come to $2975- $4550 with the lower range reflecting 17 and the high range reflecting 26 panels.

3000 sq. foot cost

For a huge home of this size, you would need no less than 44 panels. This size will generate around 14130 kWh per year. The cost would come down to $7700 of using the panels at 50 cents per watt.

Note: Here, the cost of installation has not been included and when added it will significantly increase your spendings. The cost of installation varies from company to company.

solar panels on an old home


Do solar panels work at night?

While they rise and shine with the sun’s first rays and get to work, they rest completely after sunset. This means that depending on where you live, you’ve only got the daylight hours to stock up on electric power.

You can however take advantage of nighttime hours through net metering. This solution allows power to flow to and from your home. So when you produce more than your usage, you send it back to the grid. But when you require more energy during nighttime, your local utility company provides it to you at the usual rates.

Another solution is the solar battery that allows you to store the daytime rays for your night use seamlessly. You can keep them for utility company outages or for days when the sky is cloudy and you aren’t expecting much solar to be generated. The bottom line remains that you can easily create a 24×7 solar-powered home with any of these solutions.

Is it possible to run a house completely on solar power?

While the answer to the above question maybe yes, it is still a huge decision to go fully off the grid. Not only does it require a great deal of planning but also a huge chunk out of your savings and investments. The goal of every country and its state is to reach grid parity. Grid parity means the stage where solar power costs the same or even less than the cost of using traditional electricity from the utility company. In many European countries and China, this has already been believed to be achieved.

There are many factors to consider, however, when you’re planning to go off-grid long term. First up is the cost of installation and if you can afford it. Even if you can afford the full setup, ask yourself if your house is built to take care of your solar-powered dreams. Is the location sunny on most days? Are the days longer or shorter there? Is yours sun-facing?

Even if the location is perfect, you’ll have to check if the roof is built in a manner to support all the needed panels and installations. You’ll even have to take care of the entire wiring and connect it to the panels.

If you’re concerned about costs, take a look at the state laws, grants, and rebates regarding solar installations. You could be rewarded in some way and the path of going eco-conscious could become that much cheaper for you. And even better, if you generate more power than your family uses, you could be sending power back to the grid and getting credits for it!

That’s it, folks!

We hope this article has increased your knowledge about the possibilities of renewable energy and how you can cash in on the savings it can also generate for you. The more people that hop on to the solar train, the less expensive it’ll be to install various solutions and reach grid parity. Whether it’s partial or complete solar power, this is the perfect contribution to reducing climate change and greenhouse gases in the long term. Get your hands on any of these bad boys, save money and go green – forever!

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