Production
How Much Electricity does a Solar Panel Produced and a Solar System Produce?
Solar panel production output (capacity) is the amount of electricity that a solar panel system produces when exposed to sunlight. Solar panel output (capacity) is typically measured in units of power, specifically in watts (W) or kilowatts (kW). Solar panel production represents the rate at which the solar panels produce electricity at any given moment.
Nameplate capacity for solar panels (rated capacity) (nominal capacity) or (rated output) is the maximum power output that a solar panel is designed to produce under specific standard test conditions. This value is typically expressed in watts (W) or kilowatts (kW) and is used to characterize the performance and capacity of a solar panel.
To determine nameplate capacity, factories use the International Electrotechnical Commission (IEC) standard 61853-1:2021 standard test conditions. These standard test conditions are listed bellow.
- Irradiance: 1,000 (W/m²)
- Temperature: 25 degrees Celsius (77 degrees Fahrenheit)
- Air Mass: 1.5
The total solar panel’s output is an important consideration when designing and planning a solar energy system. Solar panel’s output determines how much electricity is generated over a given period, which affects the system’s potential to offset conventional electricity consumption and reduce energy costs. The total output differs according to different real-world conditions and panels’ efficiency.
The ideal solar panels’ production does not occur in conditions. Therefore, to calculate the solar panels’ production, there are 3 steps, including collecting information about factors affecting the work of solar panels and calculating the derating factor. Finally, calculate solar panels’ production per day, month, year, or square meter or square foot.
Solar panels’production and panels their ability to generate electricity are affected by 2 real-world factors (peak sun hours, geographic location).
In addition to explaining all methods of calculating solar panels’s production with examples and discussing all the real-world factors that affect the production of solar panels, this article answers questions such as: Do solar panels store the produced energy? How do solar panels work? What to Know Before Using Solar Energy? What types of batteries store solar panel production? How effective are solar panels? What is the highest output solar panel?
How to Calculate Output of a Solar Panel ?
To calculate a solar panel output, use the following step-by-step guide.
First: Gather Information.
- Solar Panel Capacity (Wattage) (Nameplate capacity). Nameplate capacity is usually indicated on the solar panel and represents its maximum power output under standard test conditions (STC).
The nameplate capacity is determined under 3 standard test conditions, according to the International Electrotechnical Commission (IEC) standard 61853-1:2021, are in the next list.
- Irradiance: 1,000 watts per square meter (W/m²) (wattage per square meter)
- Temperature: 25 degrees Celsius (77 degrees Fahrenheit)
- Air Mass: 1.5 (a measure of the path length of sunlight through the Earth’s atmosphere)
Under these conditions, a solar panel nameplate capacity represents the maximum electrical power it generates. For example, when a nameplate capacity is 300 watts, the panel produces 300 watts of electrical power when exposed to 1,000 W/m² of sunlight at 25°C with an air mass of 1.5.
The nameplate capacity is a reference point for comparing different solar panels but does not necessarily represent the exact output you expect in everyday circumstances.
- Solar Panel Efficiency. Efficiency is the percentage of sunlight that the panel converts into electricity.
- Consider the Location. The geographical location where the solar panel is installed affects the amount of sunlight received (Solar Insolation).
Second: Calculate the derating factor.
The typical derating factors for solar panels range from 0.75 to 0.90, meaning they produce 75% to 90% of their rated output under real-world conditions, according to the Solar Energy Industries Association.
The derating factor (performance factor) or (loss factor) is a multiplier used to adjust the expected production of a solar panel system from its theoretical maximum capacity to the actual output that is achieved in real-world conditions. It accounts for various factors that reduce the efficiency and performance of the solar panels and the overall system. The derating factor is usually expressed as a percentage. The derating factor is used because Solar panels do not work at their maximum efficiency due to factors like shading, dirt, temperature, and inefficiencies in the electrical system. You should apply a derating factor to account for efficiency losses.
Third: Calculate the production of a solar panel.
Use the correct formula to calculate how much electricity a solar panel produces (per day/month/ per year/ per square meter/ per square foot)
The following sections answer the questions of What is The Average Output of a Solar Panel? How Much Power Does a Solar Panel Produce Per Day? How Much Power Does a Solar Panel Produce Per Month? How Much Power Does a Solar Panel Output Per Year? How Much Power Does a Solar Panel and System Output Per Square Meter? How Much Power Does a Solar Panel and System Output Per Square Foot?
What is The Average Output of a Solar Panel ?
The average output of a home solar panel, with a capacity of 350 to 400 watts, is 1.5 kilowatt-hours per day, in favourable sunlight conditions (1500 watt-hours), according to The National Renewable Energy Laboratory. A home solar panel, a Monocrystalline silicon panel, generates 45 kilowatt-hours per month (45000 watt-hours per month) and 540 kilowatt-hours per year (540000 watt-hours per year) on average.
How Much Power Does a Solar Panel Produce Per Day?
To calculate the daily energy production of a solar panel, use the following formula.
Daily Energy (kWh) = (Solar Panel Capacity (W) x Solar Panel Efficiency x Peak Sun Hours)
The equation to calculate solar panel production per day is shown in the following figure.
Convert the capacity from watts to kilowatts by (dividing on 1000).
Solar panel production depends on peak sun hours, which depend on the location. Peak sun hours is the average number of hours per day when the solar irradiance is at its peak.
The derating factor equation: adjusted daily energy for efficiency losses (kWh) = Daily Energy (kWh) x Derating Factor
Adjusted daily energy for efficiency losses equation is shown in the following picture.
The next example is to calculate the derating factor equation adjusted daily energy for efficiency losses.
- solar panel capacity = 400 W
- solar panel with efficiency = 20%
- Peak Sun Hours = 5
- The derating factor = 0.85
The solar panel produces = 4* 0.2* 5 = 400 Watt/ hour per day
The output is measured by Kw by dividing on 1000
the output in KW = 400/ 1000 = 0.4 KWH per day
The derating factor equation adjusted daily energy for efficiency losses = 0.4 * 0.85 = 0.34 KWH per day
We calculate how much a panel produces power and electricity by another equation :
Production of a solar panel = solar panel’s size (in square meters) * 1000 * solar panel efficiency x peak sun hours.
The following figure shows the equation to calculate production of a solar panel per day by panel size (in square meters).
The next example is to calculate a solar panel output per day.
- solar panel size = 1.5 square meters
- solar panel with efficiency = 20%
- Peak Sun Hours = 5
- The derating factor = 0.85
The solar panel produces = 1.5* 1000* 0.2* 5 = 1500 Watt/ hour per day
The output is measured by Kw by dividingon 1000
The output in KW = 1500 / 1000 = 1.5 KWH per day
The derating factor equation adjusted daily energy for efficiency losses = 1.5 * 0.85 = 1.275 KWH per day
How Much Power Does a Solar Panel Produce Per Month?
To calculate the monthly output of a solar panel, we multiply the number of days in the respective month by the daily energy production. Here’s an example to calculate the monthly output.
The next example is to calculate a solar panel output per month.
- month’s days = 30
- The solar panel produces 1.5 KWH per day (1500 WH per day)
- The derating factor = 0.85
The production of a solar panel = 1500 * 30 = 45000 Watt/ hour per month
The production of a solar panel = 45000 / 1000 = 45 KWH per month
The derating factor equation adjusted daily energy for efficiency losses = 45 * 0.85 = 38.25 KWH per month
How Much Power Does a Solar Panel Produce Per Year?
To calculate the monthly output of a solar panel, we multiply the number of days in the respective month by the daily energy production.
The next example is to calculate a solar panel output per year.
- year’s days = 360
- The solar panel produces 1.5 KWH per day (1500 WH per day)
- The derating factor = 0.85
The production of a solar panels = 1500 * 360 = 540000 Watt/ hour per year
The production of a solar panel = 540000 / 1000 = 540 KWH per year
The derating factor equation Adjusted Daily Energy for Efficiency losses = 540 * 0.85 = 459 KWH per year
How Much Power Does a Solar Panel and a Solar System Output Per Square Meter?
To calculate the solar panel’s output per square meter use this equation: panel’s output per square meter = solar panel’s capacity / solar panel’s square meter size.
The equation to calculate the output of a solar panel per square meter is shown in the next picture.
The next example is to calculate a solar panel output per square meter.
- a solar panel output = 265 Watt
- the solar panel’s size = 1.6 square meter
The solar panel produces = 265 / 1.6 = 165.625 Watt per square meter
On a solar panels system, the output per square meter = the capacity of the system / (the number of solar panels in the system * the size of one panel on the square meter)
The equation to calculate production of a solar system by square meter is in the following figure.
The next example is to calculate a solar panel output per square mete.
- A 5KW solar panels system’s capacity = 8750 KWH
- The number of solar panels in the system = 20
- Each solar panel’s size = 1.6 square meter
The solar panel system production = 8750 / (20 * 1.6 ) = 273.4375 KWH per square foot
How Much Electricity is the Output from a Solar Panel and Solar System Per Square Foot?
A solar panel’s output per square foot = the solar panel’s capacity/the solar panel’s square foot size.
the equation to calculate a solar panel’ production per square foot is in the following picture
The next example is to calculate a solar panel output per square foot.
- A solar panel output = 265 Watt
- The solar panel’s size = 17.22 square foot
The solar panel’s production = 265 / 17.22 = 14.8664 Watt per square foot
On a solar panels system, the output per of a system per square foot = the capacity of the system / (the number of solar panels in the system * the size of one solar panel on the square foot)
The equation to calculate a solar system’s production in square foot is in the following picture.
The next example is to calculate a solar panel output per square foot.
- A 5KW solar panels system’s capacity = 8750 KWH
- The number of solar panels in the system = 20
- Each solar panel’s size = 17.22 square foot
The solar system produces = 8750 / (20 * 17.22 ) = 344.4 KWH per square foot
What are the Factors that Affect Solar Panels Production?
Two external factors affect the ability of solar panels to produce electricity. The first factor is different peak sun hours which give different capacities for generating electricity. The more peak sun hours there are, the greater the solar panel’s output. The second factor is the geographical location has a significant impact on solar panels’ production.
What is The Effect of Peak Sun Hours on Solar Panels’ Production?
Peak sun hours (PSH) (Sunlight Intensity) represent the hours during which the sun’s intensity is sufficient for efficient solar energy production. Peak sun hours are when the solar irradiance equals or exceeds 1,000 watts per square meter (W/m²) (wattage per square meter).
Cloudy or overcast weather reduces the intensity of sunlight and lower the panel’s output.
peak sun hours consider factors such as the sun’s angle, atmospheric conditions, and the time of year. Peak sun hours provide a more accurate picture of solar energy potential than simply looking at the total daylight hours, as not all daylight hours have the same level of solar energy available.
Calculating peak sun hours is essential for sizing and designing solar energy systems, as peak sun hours helps determine how much energy a solar panel produces at a specific location.
The peak sun hours are shown in the following picture.
Peak sun hours in different states ( Peak sun hours in winter and Peak sun hours in summer) are illustrated in the following table.
| US State | Avg. Summer Peak Sun Hours (Hours/Day) | Avg. Winter Peak Sun Hours (Hours/Day) |
| Arizona | 7.42 Hours Per Day | 6.01 Hours Per Day |
| Arkansas | 5.29 Hours Per Day | 3.88 Hours Per Day |
| California | 6.19 Hours Per Day | 3.42 Hours Per Day |
| Colorado | 5.72 Hours Per Day | 4.44 Hours Per Day |
| Connecticut | 4.27 Hours Per Day | 2.99 Hours Per Day |
| Delaware | 4.69 Hours Per Day | 3.37 Hours Per Day |
| Georgia | 5.16 Hours Per Day | 4.09 Hours Per Day |
| Hawaii | 6.71 Hours Per Day | 5.59 Hours Per Day |
| Idaho | 5.83 Hours Per Day | 3.33 Hours Per Day |
| Illinois | 4.08 Hours Per Day | 2.47 Hours Per Day |
| Indiana | 5.02 Hours Per Day | 2.55 Hours Per Day |
| Iowa | 5.05 Hours Per Day | 2.99 Hours Per Day |
| Kansas | 6.14 Hours Per Day | 5.28 Hours Per Day |
| Kentucky | 5.97 Hours Per Day | 3.60 Hours Per Day |
| Louisiana | 5.71 Hours Per Day | 3.63 Hours Per Day |
| Maine | 5.20 Hours Per Day | 3.56 Hours Per Day |
| Maryland | 4.71 Hours Per Day | 3.84 Hours Per Day |
| Massachusetts | 4.27 Hours Per Day | 2.99 Hours Per Day |
| Michigan | 4.71 Hours Per Day | 2.70 Hours Per Day |
| Minnesota | 5.43 Hours Per Day | 3.53 Hours Per Day |
| Missouri | 5.50 Hours Per Day | 3.97 Hours Per Day |
| Montana | 5.70 Hours Per Day | 3.66 Hours Per Day |
| Nevada | 7.13 Hours Per Day | 5.83 Hours Per Day |
| New Hampshire | 5.30 Hours Per Day | 3.66 Hours Per Day |
| New Jersey | 4.76 Hours Per Day | 3.20 Hours Per Day |
| New Mexico | 7.16 Hours Per Day | 6.21 Hours Per Day |
| New York | 4.57 Hours Per Day | 2.29 Hours Per Day |
| North Carolina | 5.05 Hours Per Day | 4.71 Hours Per Day |
| Ohio | 5.26 Hours Per Day | 2.66 Hours Per Day |
| Oklahoma | 6.26 Hours Per Day | 4.98 Hours Per Day |
| Oregon 8 | 5.71 Hours Per Day | 1.90 Hours Per Day |
| Pennsylvania | 4.44 Hours Per Day | 2.78 Hours Per Day |
| Rhode Island | 4.69 Hours Per Day | 3.58 Hours Per Day |
| South Carolina | 5.72 Hours Per Day | 4.23 Hours Per Day |
| South Dakota | 5.91 Hours Per Day | 4.56 Hours Per Day |
| Tennessee | 5.20 Hours Per Day | 3.14 Hours Per Day |
| Utah | 6.09 Hours Per Day | 3.78 Hours Per Day |
| Vermont | 5.35 Hours Per Day | 3.77 Hours Per Day |
| Virginia | 4.50 Hours Per Day | 3.37 Hours Per Day |
| Washington | 4.83 Hours Per Day | 2.60 Hours Per Day |
| West Virginia | 4.12 Hours Per Day | 2.47 Hours Per Day |
| Wisconsin 6 | 4.85 Hours Per Day | 3.28 Hours Per Day |
What is Geographic Location Effect on Solar Panel Output?
Locations with higher solar insolation receive more direct sunlight, producing greater energy. Locations closer to the equator typically have higher solar insolation than those at higher latitudes.
Solar insolation is the amount of sunlight a location receives. Solar insolation is measured by kilowatt hours per square meter per day (wattage per square meter).
Consequently, solar energy systems in the southwestern regions typically yield greater energy output than those in the northeastern regions.
Solar panels should be installed at an optimal tilt and orientation relative to the location’s latitude. Proper alignment ensures panels capture sunlight at the most advantageous angles, maximizing energy production.
Do Solar Panels Store the Produced Energy?
Solar panels themselves do not store the energy they produce. Householders use batteries to store the energy generated by solar panels for use when the sun is not shining, such as during nighttime or on cloudy days. Solar batteries store the excess electricity generated by the solar panels and release it when needed.
Solar panels work only to generate electricity when they are exposed to sunlight, and this electricity is either immediately used to power electrical devices or fed into the electrical grid. This power is stored in lithium-ion, lead-acid, flow, and other types of batteries.
How Do Solar Panels Work?
Solar panels work by absorbing sunlight and outputting electricity through a process called the photovoltaic effect. Each panel contains photovoltaic cells, typically made of silicon, that absorb photons from the sun’s infrared radiation and produce electric current.
To make solar panels work efficiently, you need to know first how many watt-hours do you need. To know How do Solar Panels Work, they use solar energy to output electricity as long as there is sunlight, reducing reliance on non-renewable energy sources and lowering environmental impact.
Solar panels work does not contains energy storing, so you need to use batteries to store solar Panels’ production. And to determine how effective are solar panels, check the highest output solar panels in the market
How Many Watt Hours Do I Need?
To determine how many watt-hours you do need, you’ll need to collect information about the specific devices you’re using and the duration of use. The formula to calculate how many watt-hours you need is:
Watt-hours = Watts × Hours
Calculate how many watt-hours do you need for each device and then add them up to get the total watt-hours required. When calculating how many watt-hours do you need, make sure to consider the power consumption (in watts) and the time the devices in use (in hours).
What to Know Before Using Solar Energy?
Solar energy is like a giant, clean, renewable power plant in the sky that output down clean, renewable energy to Earth. The sunlight that reaches the Earth’s atmosphere encompasses visible light, infrared radiation, ultraviolet (UV) and other forms of electromagnetic radiation. To produce electricity, different tools and technologies harness solar energy and convert it into electricity or heat instead of using fossil fuels.
What Types of Batteries Can Store Solar Panels’ Production?
Solar panel production (output) is stored in various battery types (Lithium-Ion Batteries, Lead-Acid Batteries, Flow Batteries).
When choosing a solar panel’s battery for energy storage, it’s important to consider factors (capacity, cycle life, efficiency, upfront cost, and maintenance requirements ). Additionally, the battery bank size should match the energy production and consumption needs of the solar system.
How Effective are Solar Panels?
The solar panel’s production efficiency (the average conversion rate of sunlight into usable energy) is 15% to about 20%, with some high-efficiency panels achieving nearly 23% conversion rates, so they produce more energy. In recent years, there has been a significant improvement in the production solar panels efficiency to output more electricity.
What is the Highest Output Solar Panels?
Monocrystalline panels provide the highest production rate and power output among solar panel options. While they come with a premium cost, their enduring advantages justify the initial investment. These Monocrystalline panels boast a more compact design, making them an excellent choice for residences with restricted roof space.