Did this question ever come to your mind, “How many solar panels are needed to power a house”? Let’s dive deep into it and find what the answer is to this problem. There are certain complexities before determining the total number of panels that will be required. In this blog, we will study the mathematical formula to find the number of solar panels that can power a complete house and the factors that can affect the number required. But still consulting professionals for an accurate estimate is always advised.


According to an estimate, an average house of 2480 square feet (ca. 230 square meters) requires 15-22 standard-size solar panels to give energy to the entire house. However, there is a mathematical formula through which you can get an estimate of the number of panels required to power your house. According to this formula, you need to divide your annual electricity consumption by your area’s production ratio and then divide the number of power output generated by the solar panels you are planning to buy. Using this formula you can make an estimate but still, numerous factors can impact the results of this calculation up to a great extent. You should know that this formula is based on suppositions.


Many factors can influence the number of solar panels that are required to power a complete house. The factors include the house’s electricity consumption, the size of the solar panels, the wattage of the solar panels, production ratios, access to sunlight and climate of the area you live in, and the size of your house. All these factors directly affect the number of solar cells you need, such as if the size of solar panels is less it will absorb less energy producing less power and thus more of these panels will be required. 

House’s Electricity Consumption:

If you want to know how many panels are needed to power a house completely, you must know your house’s electricity consumption first. The number of panels will largely depend upon your power consumption. If the usage is high then the number will be high and if the usage is low then the number will be low. Similarly, if your house has energy-efficient appliances, then your consumption will be low, and you will need fewer solar cell installations. Still, if you don’t use energy-efficient appliances, then you might need more cells to power it completely. For example, a house consuming 500 KWH of energy will require less number of panels than the one consuming 800 KWH.

Size of the Solar Panels:

The size of the solar panels can also affect the calculation’s results. If your house’s roof has ample amount of space you can get the huge less expensive solar panels that can absorb more heat and produce more power. When more energy is being generated, it means you will need less number to fulfill the needs of the whole house. On the other hand, if there is less open space on the roof you will have to get smaller solar cells, they will be expensive and won’t make much power. The average size for residential purposes is 65 by 39 inches (ca. 99 cm), and it can vary depending on the brand you are using.

Wattage of Solar Panels:

The wattage of the solar panels is one of the major factors that influences the needed number of solar collectors. Wattage means the amount of power that it will make from the sun. If you are planning to purchase one with more wattage then you will need fewer of them but if you are buying the ones with lower wattage you will have to get more of them. You need to know how much wattage you need before going out to buy your property. Such as panels with 250 Watts power output will be required more in number than the ones with 400 Watts.

Production Ratio:

The production ratio is the ratio between the estimated energy output and the actual size of the system. The ratios between both are never equal because the sunlight doesn’t remain the same on the cells. So, if in the production ratio, the output is more then you do not require many panels. But if in the production ratio, the output is lesser than the input then you might have to buy more panels to power your house completely. This is how the production ratio influences the number of panels required to power a complete house.

Access to Sunlight and the Climate:

If you are living in an area where you get sunlight around the year, then you don’t need many solar panels installed to meet the needs of your house because this climate will give you good power output. But if you are living in a climate zone where it is not usually sunny, you will not have much advantage of installing panels there. So it is very important to check the compatibility of solar energy with your climate, if it is compatible then you can use it to power your house. If there is no compatibility there is no benefit, think wisely.

The Size of your House:

We can assume that the bigger your house, the more power consumption. This is because you will be using more power for lights and other appliances to cover such a large area. So we can say that the size of your house is directly proportional to the number of solar panels required to power it because of more power usage. You can make a rough estimate of how many panels will you need to give energy to your whole house based on this information. On average, a 1500 square feet (ca. 139 square meters) home uses 630 Kilo Watts of energy.

Budget You Should Have For Installation:

From the above information, you can calculate how many solar panels you need for your property. Now you need to check your power usage, your property’s coverage area, and the quality and type of the cells. Apart from this, you will also need to buy other equipment to give solar power to your home, such as batteries and inverters. Monocrystalline, Polycrystalline, PERC, and thin-film panels are different types of panels and have different prices. You can select the one that fulfills your needs the most and use the above information to have an estimate of the budget you will require to install a solar system at your home. On average, you should have somewhere between $16,000 and 35,000 for a good setup.

Are Solar Panels Compatible for You?

Going green and installing a solar system in your home can be a very good decision, but on the other hand, it will be of no use if you get it installed without checking its compatibility. If you live in an area where the climate is hot and sunny, your house gets a clear view of the sky without any trees or taller buildings covering the sun, your energy bills are high. If your state offers incentives for using solar energy, then the solar panels are the best fit for you. You can decrease your energy bills and decrease carbon emissions using sun-powered energy.


Solar panels are very effective and can give you many benefits including unlimited power sources, low maintenance, and saving money on bills. If you want to get them installed to power your home completely, then you can use different mathematical formulas to find the number of panels to fulfill your needs. However, you should also know multiple factors that can affect the estimate given from this formula. Such as if you are living in a climate zone where there is not enough heat and sunlight, then you will have to get more solar cells to meet your power needs. You can use the information from the above blog to find the answer to your question, but it is always better to get an accurate estimate from professionals who have expertise in this field. However, it is considered that 17–21 panels are enough for an average home.