Solar Panel Efficiency is basically the percentage of energy. However, it explains the solar energy shining on a device.
There we need to consider two things. One is the total energy. At the same time, the other one is the usable energy. The first one relates to the power of the sun.
However, the second one is the energy that is converted. But, we are in need of useful energy. Therefore, the conversion sort of energy matters.
Table of Contents
Types of elements on the basis of PV modules
This article is all about efficiency in a PV module. Therefore, it is necessary to discuss the basic elements. However, these are two in number.
One is a Solar cell while the other is a panel. So, let us discuss both on an individual note.
Solar cell
The device that converts light energy to electric energy by the photovoltaic process
It is basically an electronic device. Therefore, this process effectively explains electricity conversion. Below are important steps of energy conversion by solar cells.
- Photons are an integral part there with energy
- Material absorbs photons
- Due to the photoelectric effect, material moves with photons
- Photons have energy on the basis of movement
- Due to the PV effect material and electrons move
- However, with high or low movement energy is predicted
Panel
In solar panels, we observe the presence of arrays of PV cells. Especially, the arrangement especially makes it unique.
Further, the interesting thing is the interconnected function. Therefore, the PV module with many cells constitutes a panel.
Difference between Solar Cell and Panel
Anyhow, the important difference between the two is obvious. A solar cell is a tiny part while a panel acts as a collection of cells. There are different numbers of solar cells in panels.
These consist of 32,36,48,60, 72, and 96 cells. Another major difference is the criteria for getting energy. A cell gets energy directly from sunlight while a panel works on output energy.
How to calculate Solar Cell Efficiency?
It explains the measure of the extent to which a solar cell can convert energy. This process includes two of the parameters. One is Output electric energy and the other is Incident Light energy.
So, on behalf of these, there is an important formula as below.
Efficiency= Output Electric Energy/ Incident Light Energy x 100
This parameter relates to the specific aspects of Solar Cell Efficiency. However, we need to assure a detailed explanation.
Important terminologies
- Isc
The current that flows when no voltage is present
- STC
Standard conditions of testing. Here, the values are fixed. These follow the industrial values being there already.
However, these are extremely helpful to find the calculations. Especially, when there is no idea with values then we can follow it accordingly.
- Voc (Open circuit voltage)
When no current flows the current. This condition is also the neutral point
- Im (Maximum current)
The extent to which current is there at the panels. It effectively explains the limit. However, its value should not increase or decrease.
- Vm (Voltage maximum)
It is similar to the current. Further, it works in an effective manner within the optimum value. Its value is 600 – 1000 V
- FF (Fill factor)
The factor that shows the quality of solar cells. It is essential to note this for tracking efficiency. However, below is an important equation.
Fill factor= Pmax / Iac x Voc = Im x Vm / Isc x Voc
How to calculate the Irradiance? (Pin)
It is basically the radiance energy from the sun. Here, energy from the sun acts as a primary source for photovoltaics.
It is therefore necessary to calculate solar cell efficiency. However, below is the formula for that.
Ii = It cos θ
Here,
Ii= Surface irradiance
It= Overall irradiance
θ= Angle of incidence
Method to calculate the maximum power
An important terminology that shows the highest power output. Here, we need to focus on the maximum output under STC.
Let us follow an important example. Suppose a solar panel is tested at STC. It grants about 150 W of power output.
This factor shows the Pmax to be 150 W. Ii is an important parameter with performance and efficiency.
On an average Pmax, the rating consists of varying values. However, the optimum range lies between 265 to 395 W. Anyhow, it all depends on panel design and manufacturing.
How to calculate Solar Panel Efficiency?
There is a formula for that, however, it consists of the following estimation.
Panel Power/ Panel Length x Panel Width x 100
Important points
- Efficiency has a direct relation with the surface area. There exists a greater dependency on the determination of panel efficiency
- Identification of solar panel efficiency depends upon the sunlight energy
- A solar panel can never be 100% efficient or ideal
Method of calculation
To calculate the solar panel efficiency suppose we have a 300w polycrystalline solar cell. So, its specification is listed as:
|
Aspect of dimensions |
16499 |
|
Maximum Power |
0.4 |
|
Power Circuit which is maximum |
32.7 |
|
Current being maximum |
9.17 |
|
Voltage with open circuit |
39.80 |
|
Current with short circuit |
9.78 |
|
Relevant Mass |
19 |
Using the formula of Efficiency
𝜼 = 0.4 / 1.64 x 0.99 x 100% = 24%
We also want to know the quality, therefore, let us follow an equation.
Using the fill factor formula.
FF= 9.17 x 32.7 / 9.78 x 39.8 = 0.77
𝜼 = Pmax / Pin = Isc x Voc x FF / Pin = 9.78 x 39.8 x 0.77 / 1000 x 100% = 29.9
Here, we make use of 1000 for Pin
So, we come to know the efficiency by this formula.
Real Life Example under STC
To do so we need to follow up on the STC conditions. However, there are three conditions to fulfill. So, these consist of the following.
Temperature of cell = 25
Irradiance = 1000
Mass of Air = 1.5
For the measurement, we need to follow certain steps.
- Make use of a testing apparatus. However, it helps to measure voltage and current output
- Fulfilling the fact that solar panel works at an irradiance level of 1000. It can be done with a solar simulator. Especially, the one that uses intensity and spectral levels
- 25℃ seems as the optimum temperature. If the temperature is not known this is used as a constant temperature
- Calculation of voltage and current output at irradiance level. These methods are therefore helpful to calculate power output
- Solar panel efficiency is calculated by formula. Below one is.
𝜼mp STC = YPV / APV x GT, STC
Here,
All of the quantities are following STC
𝜼mp = Module efficiency of PV
YPV = Power output by module
APV = Surface area on an overall note
GT, STC = Radiation
Anyhow for different panels method is the same. However, by comparison, all can be done effectively.
Moreover, certain conditions can affect the overall efficiency. These include:
- The higher temperature of the cell above 25℃
- The lower level of irradiance
- Changing values
What are the factors that affect the solar panel efficiency?
-
The intensity of sunlight and angle
It refers to the energy or radiation that reaches Earth. Here, we need to follow the accurate angle. It is therefore between the surface of the earth and sun rays. However, these credentials influence efficiency in many ways.
For instance, let us consider the angle that reaches Earth. It consists of an accurate angle. So, the 90-degree angle here acts as ideal. Further, the most intense impact happens in this position.
Therefore, we need to follow this condition. But, if there is an altered angle then efficiency is not proper.
For this, we need to see the angle of incidence. So, it is basically:
The angle formed between two rays. These are the incident ray and the normal. So, both of these rays form an angle at a point. This particular point is called the angle of incidence.
Whenever the angle of incidence is lower it results in a large surface area. Due to this, we experience the covering of sun rays. This condition, therefore, affects the efficiency.
-
Temperature influence
This factor has its own significance. It should not be having a higher value. One thing is certain here in the form of low temperature. This condition works better for Solar Panels.
Further, the high temperature adds a negative influence. It damages the material of cells and reduces the life span. However, it is overall a damaging thing for Solar Panels
Despite of these factors other are lots of ways to maximize solar panel efficiency. You can follow tips to maximize solar panel efficiency
What are the factors that affect the solar panel efficiency?
-
The intensity of sunlight and angle
It refers to the energy or radiation that reaches Earth. Here, we need to follow the accurate angle. It is therefore between the surface of the earth and sun rays. However, these credentials influence efficiency in many ways.
For instance, let us consider the angle that reaches Earth. It consists of an accurate angle. So, the 90-degree angle here acts as ideal. Further, the most intense impact happens in this position.
Therefore, we need to follow this condition. But, if there is an altered angle then efficiency is not proper.
For this, we need to see the angle of incidence. So, it is basically:
The angle formed between two rays. These are the incident ray and the normal. So, both of these rays form an angle at a point. This particular point is called the angle of incidence.
Whenever the angle of incidence is lower it results in a large surface area. Due to this, we experience the covering of sun rays. This condition, therefore, affects the efficiency.
-
Temperature influence
This factor has its own significance. It should not be having a higher value. One thing is certain here in the form of low temperature. This condition works better for Solar Panels.
Further, the high temperature adds a negative influence. It damages the material of cells and reduces the life span. However, it is overall a damaging thing for Solar Panels
Conclusion
This overall discussion states important points with efficiency. Here, the calculation depends upon a step-by-step methodology. Further, we come across some of the necessary factors. Therefore, it effectively explains the necessary criteria for measuring solar panel efficiency. However, it serves as an essential study on a futuristic basis. So, when it comes to purchasing, consider a reliable source. One such source is the Clean Power Store. You can purchase the most efficient solar panels, from clean power store (USA’S best solar distributors )at wholesale price.