Solar Panel Size Guide for residence and industry

Do you always ask yourself what could be the physical size of the solar array system you normally see on other people’s roofs? Or wondered what could be the standard size of a residential solar installation that would cater for all the energy consumption of an average home because every solar panel installation you see tends to vary quite a lot?

Maybe your concern is in the weather conditions in your area that make you wonder if there will be sufficient hours of sunlight per day to make the solar panel produce enough electricity to match your domestic or commercial energy usage.

The upfront cost of residential installations of standard panels (a 250 watt panel for example) may vary from country to country but this article includes estimated cost per panel and also gives you the number of panels needed for specific electrical energy requirements or per kWh of energy i.e target energy output.

the solar energy production or the solar power output for common configurations in residential projects or commercial projects can be determined by determining a few key factors like the solar panel wattage, the average irradiance, the panel efficiency, and your energy demand.

Solar Panel Size and Wattage

Wattage in (Watts)Width in (Inches and CM)Length in (Inches and CM)Solar Panel Voltage in (Volts)Thickness in (inches and cm)
50 watts per Panel21 inches 53.34 cm26 inches 66.04 cm12 volts1 inch 2.54 cm
100 watts per Panel21 inches 53.34 cm47 inches 119.38 cm12 volts1.5 inches 3.81 cm
160 watts per Panel26 inches 66.04 cm58 inches 147.32 cm12 volts1.5 inches 3.81 cm
                                    Flexible Panels 
50 watts per Panel21 inches 53.34 cm26 inches 66.04 cm12 volts0.1 inches 0.25 cm
100 watts per Panel21 inches 53.34 cm48 inches 121.92 cm12 volts0.1 inches 0.21 cm
160 watts per Panel26 inches 66.04 cm55 inches 139.7 cm12 volts0.1 inches 0.21 cm
Solar Panel Size Guide: Which Size Of Solar Panel Is Best?
Solar Panel Size Guide

Solar Panel Sizes and Expected Prices

It may look a bit expensive at first glance, but the guarantee period that you will be given by the solar installation company that you will choose will show you that it takes a small fraction of the useful life of the solar panels to get your returns on investment and you are left with all the remaining time to enjoy profits in a safe, reliable and sustainable way of energy generation.

Solar System Size in (Kilowatts)Cost Estimate in (USD)Cost Estimate in (Euros)
25 kilowatts43,750 to 56,35038211.25 to 49216 Euros
50 kilowatts87,500 to 112,70076422.50 to 98432.18 Euros
100 kilowatts175,000 to 225,400152845 to 196864.36 Euros
250 kilowatts437,500 to 563,500382112.50 to 492160 Euros

How to choose the right solar panel size

The very first step in the process of determining the size of solar panel you need is first determining your monthly energy consumption. This can be done by checking your kWh reading on the bill but the best way is to add the readings from the past twelve months then divide by twelve to have the average monthly consumption.

Just for comparison, an average home in the US consumes approximately 900kWh per month which is 30kWh a day or more specifically 1.25kWh per hour. Next, you need to find out about the intensity of sunlight your area receives which is called the sun peak hours to enable you to determine the amount of electricity in kilowatt-hour that 1kWh of solar panel will be able to produce

With this in mind, you can now determine the total solar system size you need to cover the energy consumption that you want to cover with solar energy.

Finally, calculate the number of solar panels you need, divide the figure of the solar system size in kilowatts to the wattage of the solar panels sold in your area and you now have the total number of solar panels needed to cover the energy consumption for your home or business.

Solar Cell Sizes for Residential Panels and Commercial Panels

Solar Cells per ModuleLength in (inches and cm)Width in (inches and cm)Depth in (inches and cm)Area in (square feet and meters squared)Wattage
6065 inches 165.1 cm39 inches 99.06 cm1.5 inches 3.81 cm17.7 square feet 1.64 meters squared175 to 240 watts
7278 inches 198.12 cm39 inches 99.06 cm1.5 inches 3.81 cm21.2 square feet 1.96 meters squared250 to 300 watts

370-Watts Solar Panel Power Production in Varied Solar Irradiance Level

StateNumber of Peak Sunlight Hours per DayDaily Electricity Production
California62.2 Kilowatt Hour
Arizona7.52.7 Kilowatt Hour
New Jersey41.5 Kilowatt Hour
Alaska2.50.93 Kilowatt Hour

Solar Panel Electricity Production by Model

The figures in the table below are meant to help the reader match his or her daily electrical energy consumption with the number of solar panels needed to produce the same energy needed. After determining the average intensity of sunlight your area receives, you can determine the energy production expected per kilowatt-hour of the solar panel model you’ve chosen from which the total number of panels can directly be derived through a simple and direct calculation that is discussed in this article.

Solar Panel ModelPower RatingApproximate Daily Power Production (kWh of electricity)
Q. CELL Q. PEAK Duo385 W1.98 Kilowatt Hour
LG NeON405 W2.03 Kilowatt Hour
Panasonic EverVolt380 W1.90 Kilowatt Hour
SunPower A Series425 W2.3 Kilowatt Hour
REC Group Alpha Series405 W2.03 Kilowatt Hour

Number of Panels Required and The Roof Space Needed

It doesn’t really matter the type of roof that you built for your home. Whether it’s a flat roof, dome-shaped, or whichever kind of roofing you have, it can all be turned into a usable roof for solar panel installations. There are of course alternative sites around your premise that can be used for the same installations. The table below is a guide on the surface area needed for different solar panel wattages.  

Solar Panel System SizeApproximate Monthly Solar Panel OutputNumber of Solar PanelsRoof Space Needed in (square feet and meters squared)
4 kW480 to 600 kWh13220 sq. feet 20.43 meters squared
6 kW720 to 900 kWh19330 sq. feet 30.65 meters squared
8 kW960 to 1200 kWh25439 sq. feet 40.78 meters squared
10 kW1200 to 1500 kWh32549 sq feet 51 meters squared
12 kW1440 to 1800 kWh38659 sq feet 61.22 meters squared
14 kW1680 to 2100 kWh44768 sq feet 71.34 meters squared

Solar Panel Efficiency Table

As you can see in the table below, there seem to be small margins between the efficiency levels of solar panels from different manufacturers. This means that you would be good to go with the brand that is locally available in your area instead of waiting for long shipment periods to acquire higher efficiency solar panels.

Solar Panel ManufacturerMaximum Efficiency Rating
LONGi20.9 %
Solaria20.5 %
LG22.0 %
Hanwha20.3 %
JA Solar20.4 %
Sunpower22.8 %
JinkoSolar20.38 %
QCELLS20.6 %
Rec Solar21.7 %
Panasonic21.2 %

Solar Panel Sizes and Weight (60 cell 250 Watts panel)

Solar PanelSolar Panel Dimensions in (millimeters and inches)Average Weight in (kgs and pounds)
Jinko Solar Panel 255W1650 by 992 by 40 mm 64.96 by 39 by 1.57 inches19 kgs 41.88 pounds
Waaree Solar 250W1640 by 990 by 40 mm 64.56 by 38.97 by 1.57 inches22.2 kgs 48.94 pounds
Canadian Solar CS6K1650 by 992 by 40 mm 64.96 by 39 by 1.57 inches18.2 kgs 40.12 pounds
Vikram Solar Eldora Neo Series1640 by 992 by 40 mm 64.56 by 39 by 1.57 inches18.5 kgs 40.78 pounds
Trina Honey Series1650 by 992 by 35 mm 64.96 by 39 by 1.377 inches18.5 kgs 40.78 pounds

Solar Panel Size and Weight Chart (72-cell panel 300W)

Solar PanelDimensions in (mm and inches)Weight in (kgs and pounds)
Jinko Solar Panels1956 by 992 by 40 mm 77 by 39 by 1.57 inches26.5 kgs 58.42 pounds
Waaree Solar Adifya Series1960 by 990 by 40 mm 77.16 by 38.97 by 1.57 inches22.2 kgs 48.94 pounds
Canadian Solar Dymond Series1968 by 992 by 58 mm 77.48 by 39 by 2.28 inches27.5 kgs 60.62 pounds
Vikram Solar Eldora Grand Series1955 by 991 by 40 mm 76.96 by 39 by 1.57 inches22 kgs 48.50 pounds
Trina Tall Max Series1956 by 992 by 40 mm 77 by 39 by 1.57 inches22.5 kgs 49.60 pounds

Industrial Solar Panel Sizes and Area Required

For industrial clients of solar panels, here is a guide for the number of panels and an estimated area required for the installations.

Solar System SizeNumber of PanelsRoof Space Required in (meters squared and square feet)
1.5kW59 meters squared 96.875 square feet
2kW610.3 meters squared 110.868 square feet
3kW915.4 meters squared 165.764 square feet
4kW1220.4 meters squared 219.583 square feet
5kW1525.5 meters squared 274.479 square feet
6.6kW2034 meters squared 365.973 square feet
10kW3051 meters squared

What is the best solar panel size for you?

As this article has outlined above, the best solar panel size for you depends on your domestic or commercial energy consumption, or on the part of your electrical energy consumption that you intend to cover with solar energy.

Most of the residential solar panels are rated at 250 to 300 watts each and from the wattage figure, you can always calculate the number of panels needed for specific electrical energy consumption figures through the steps shown in this article. Choose the most efficient solar panel available in your area, though the efficiency figures tend to vary in very small margins so this shouldn’t be a worry to you.

Solar Panel sizes explained

Sizing your solar panels by Projects With Everyday Dave


With a focus on sustainability in matters of energy production, solar energy is undoubtedly at the top of the list. There is an unlimited supply of solar energy on our planet that can be harnessed using solar panels of any type or size. Solar installation companies can now be found in almost every part of the world and they would be happy and willing to assist in case you have any concerns or further information that you would need to help you make a decision regarding solar energy.

Don’t wait any longer to do away with your usual electricity utility bills because you can start with small size solar panels to offset part of your electricity consumption and then go step by step scaling up until you cover all your electrical energy consumption using solar panels. 

If you enjoyed reading this solar panel size guide, please don’t hesitate to leave a comment below!

Picture in this post by Bill Mead on Unsplash

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