How to Calculate Solar Panel Efficiency Whenever You Buy Solar Panels?

What is the Efficiency of Solar Panels?

The solar panel is a static electronic device used to generate electricity by converting renewable energy. That’s why efficiency comes into question. Efficiency is a crucial thing for any electrical and electronic device. There is a basic solar cell efficiency formula and this solar PV module efficiency calculation is considered a basic efficiency calculation formula. Electrical efficiency is defined as the output power of a circuit divided by the input power of a circuit. The solar panel is an electronic device that’s why the efficiency of solar panels can be defined this way. If we think about solar panels the efficiency of the solar panel is depending on the sunlight and the radius of the solar panels. However, let’s see how to calculate solar panel efficiency whenever you buy solar panels. 

How to drive solar panel efficiency formula?

If you would like to calculate solar panel maximum efficiency then you have to figure out the ratio of solar panels and the solar power by the panel area in square meters and multiply by percentage. However, let’s see the solar panel maximum efficiency formula. Efficiency = Panel Power in KW/Panel length * Panel Width. To specify this formula, you can multiply with 100 (percentage). Suppose you have some PV panels each panel capacity is 200 watts (0.2KW) and length is 0.1.50m and the width is 0.90 and multiply by 100%. So, the solar panel efficiency formula derivation is efficiency = Panel Power / Panel length * Panel Width * 100%

                               0.2KW /1.50 *0.90 *100% = 14.9%

There are three main types of solar panels you can use this formula and remove your fear that how to calculate solar panel efficiency.

How to calculate efficiency of solar panel?

How to calculate efficiency of solar cells? There is an easy solar cell efficiency calculation process that we will let you know literally. Whenever you go to buy a solar panel you should understand how it is suitable for you and how much power you need. If you would like to buy a solar panel first of all you have to know your load demand, PV cell efficiency, and cost. However, let’s see how to calculate solar panel efficiency whenever you buy solar panels.

  • First of all, you have to decide the rated power of the solar panel (how much energy you need).
  • Find the length of the solar panel.
  • Find the width of the solar panel.
  • Figure out the area of the solar panel.
  • Figure out the output power of the panel.
  • You have to know the input power of the solar panel.

However, we are going to explain the solar panel efficiency equation or solar module efficiency calculation. Suppose you have a solar panel it has 350 watts, a length of 1.985, a width of 1.003, and an area of 1.991m2 and output power is 175.8 watts/m2 and the input power is constant at 1000 watts/m2. However, the exact or current solar panel efficiency formula is given below. The Efficiency = Panel Power in KW/Panel length * Panel Width

It is noted that this formula will lead you to find how is the solar panel efficiency or how to do solar panel efficiency calculation that you necessary to know before you buy solar panels, and before installing photovoltaic cells.


In this case, to find the area you have to multiply the length and width (1.985 * 1.003). After obtaining the area of the panel then you have to divide by the solar panel’s total watt and the area of the PV panel (350/1.991) then you will get solar panel output power.

It is noted that solar panel input power is 1000 watts/m2 it is a constant or world standard value that we get from sunlight. Now the formula for the efficiency of solar cell is out power divided by input power (1.75.8/1000) = 17.57% the total efficiency of your decided solar panel is 17.57%. This is the solar PV efficiency calculation you can find the efficiency of any solar panel by using this method.

Monocrystalline solar panel efficiency

The Monocrystalline solar panel is a solar panel that is made from silicon but to manufacture a Monocrystalline solar cell a seed crystal is submerged in a liquid silicon bath that’s why the Monocrystalline solar panel is considered as a highly efficient solar panel in the world. We have seen the Monocrystalline solar cell efficiency calculation and we got to prove that the Monocrystalline solar cell performance is higher than the Polycrystalline solar panels. It is noted that the Monocrystalline solar panel is the maximum efficiency of solar cells and the mono solar cell is the most efficient photovoltaic cell.


 The Monocrystalline solar panel efficiency is more than 28% and it is the more useful solar panel that can easily generate higher energy than Polycrystalline solar panels. However, it is noted that if you would like to find Monocrystalline solar cell efficiency then you should follow the above solar cell efficiency equation and it is the easiest process to find photovoltaic cell efficiency.

Polycrystalline solar panel efficiency

The polycrystalline solar panel is a popular solar panel that has a large number of silicon crystals into one Photovoltaic cell. Silicon photovoltaic cells have an efficiency of 25% to single crystalline cells. Nowadays Polycrystalline solar panel efficiency is 23% but scientists are trying to improve it the conversion of a polycrystalline silicon solar cell efficiency is 13% to 16% but it is improving gradually.

Basically, the efficiency of solar cells is depending on the panel construction. On the other hand, Polycrystalline solar panel price is comparatively lower than Monocrystalline solar panel. For those who would like to use it for lower load Polycrystalline is perfect there. So calculate solar panel efficiency whenever you buy solar panels but don’t buy low-efficient solar panels for your home, offices, and industries.

Thin Film Solar Cell Efficiency

The thin film solar cell is one of the second-generation solar cells that have been created with the help of more than one layer, or thin film of the photovoltaic material which involves glass, metal, and plastic. Thin Film solar cells are profitably used in many technologies counting cadmium telluride (CdTe), amorphous thin-film silicon (a-Si, TF-Si), and copper indium gallium diselenide (CIGS).  

Since the late 1970s, the thin film cells have won the hearts of millions. The product has achieved a way more famous when the solar calculators are vitalized by the small strip of amorphous silicon which has been developed in the market. These items will be available in the vehicle charging systems and building integrated solar panel installations.


Even though, thin film technology was anticipated to bring better and more advanced one and transcend the crystalline silicon (c-Si) technology in the interminable, market share has been diminishing for several years now. Back in 2010, there was an efficiency of standard PV module, the thin film considers 15% of the potential market which has reduced by 8% in 2014. This situation was expected to improve by 7% in 2015; along with amorphous silicon, it was anticipated to experience half of the market share by the end of the time.

Thin film solar cells are less expensive than Monocrystalline and Polycrystalline solar panels. Usually, they have low power capacity and are less efficient. The efficiency of the thin solar cell depends on the thin film photovoltaic cell. In 2015, the globe’s biggest copper indium selenium solar cell also known as Solar Frontier received a conversion efficiency of 22.3%. The conversion efficiency has risen by 0.6% but maximum thin film solar absorbs an efficiency rate of 6% to 18%. It is noted that you can choose one within three of them as your high-efficiency solar PV modules.

Why solar panel efficiency is low?

Why solar panel efficiency is low? The answer is straightforward. It means PV panel efficiency depends on a few factors such as Photovoltaic length and width, solar energy materials and solar cells, or solar panel materials. Basically, solar panel efficiency depends on sunlight and solar panel size. However, efficiency is important and output power depends on efficiency. If efficiency becomes high then the output power or energy conversion will be high.

PV panel efficiency is not exactly low and this efficiency is higher than some other natural energy sources. The solar panel efficiency is 15% to 22% but the average efficiency is more than 20%. It is noted that panel efficiency depends on the size of the solar panel. However, if we compare efficiency with some other commercial energy sources (coal, oil, and gas) then solar energy efficiency is high based on overall consideration. It is noted that solar panel efficiency becomes low during off-sun periods like rainy days and cloudy weather.

Let’s explain why solar panel efficiency is low. Many people love the development of solar panels which have become one of the demandable products in the market and these solar panels have become commercial with innovative support. Basically, the photovoltaic system solutions are within the medium and long term. The trend became a work in progress in 2006 with an installed capacity of 6W which advanced better in 2018 with a capacity of 480.6 GW internationally. 

The main source of solar panels is the sun. Sun provides energy in the form of light which is later composed together in terms of photons. Each photon contains a unique wavelength range and energy. These solar panels transform sunlight into electricity which has been powered by photons that are utilized by photovoltaic cells. The cells have been made with the help of a semiconductor (p-n junction) which assists the electric currents when the photons are absorbed.


The enormous parts of sunlight don’t always hit the cells which cannot get transformed into electricity. Sometimes solar cell efficiency faces a problem of physical conversion of sunlight. William Shockley and Hans Queisser have explained the basic principle of the solar photovoltaic industry. The theory showed that supreme art efficiency is present which is 33.7% and with help of these the standard photovoltaic cell can generate electricity from the source of light.  

The Shockley Queisser Limit explained the physical process of photon absorption with the help of semiconductor material in which electrons from the atoms precede the conduction band inside the solar cell. The photons which welt the solar panels from being considered from the surface of the cell.

Among the absorbed photons, some of them are turned into heat with the help of the internal recombination process rather than producing electricity. These losses of efficiency are inevitable. There are some of the reasons for which this efficiency is losing its value, for instance, insulation resistance, design configuration, snow, hail, ice and dust, and effects of temperature. 

Fill Factor and efficiency of solar cell

The fill factor is a parameter that operates with Voc (open circuit voltage) and Isc (short circuit current) which controls the maximum power of the solar cell. The Fill Factor is the ratio of maximum power from a solar cell of the products f Voc and Isc. 

FF = Pmp / Voc * Isc

The open circuit voltage and short circuit current are the voltage and the current respectively of a solar cell. The fill factor (FF) estimates the squareness of a solar cell and the largest area of the rectangle which do fit the IV curve. The equation describes the importance of the Ideality Factor and it can also be recognized as the “n-factor” of a solar cell.

The ideality factor evaluates the quality of the junction and types of recombination of a solar cell and the value of the n is nevertheless, some of the mechanisms of recombination have inaugurated that the value of the recombination mechanisms is the FF always remains lowers since there is a presence of parasitic resistive losses.

The FF is usually used for the measurement from the IV curve. Many successful businesses love spending on profit-oriented solar panels. Some solar panels don’t receive enough maintenance to produce better output to generate electricity. There are several ways through which the efficiency of profit-oriented solar panels can be improved.

1. Buy better and more efficient models of solar panels. The efficiency of the panels is hitting the panels of photovoltaic solar cells which later transforms into electricity. Better solar panels will provide the best results.

2. Buy strong Photovoltaic (CPV) cells. The best solar panels provide 22% of efficiency and on the other hand, cells of CPV panels can generate 46% of efficiency. 

3. Avoid installing solar panels in covered areas. If the one photovoltaic cells remain in shaded areas the energy can be generated by the neighbor cells. This situation happens when resistors are within their power. The buildings and tall trees are the two delinquents in terms of shading solar panels. A planning process needs to be taken to select a better site and confirm that the shade will not create any concerns.

4. Hire a professional to install the solar panels. To receive and generate better electricity it is necessary to install the solar panel correctly. The solar panels should be fixed within 18 to 36 degrees so that the efficiencies are not harmed by the temperature. A gap between the roof and solar panels permits the air to pass and saves the photovoltaic solar panels from being warmed. 

5. Clean the solar panels. The dust and dirt can create low efficiency and reduces the output by 5%. The areas which cannot receive an adequate amount of rainfall might reduce the output by 20%. 

6. Observe the out of the solar panels with energy management software. The energy management software will help the owner to remain protected from any unpredicted circumstances and the output. 

What is the average efficiency of solar panels?

The average efficiency of solar panels is 15 to 18% but we can manually improve PV cell efficiency whenever we install the solar panels. i8t is noted that we hope we will get more efficient PV cells in the future due to technological expansion. However, the better the photovoltaic solar panel the greater output can be achieved from the light which hits the cells and requires less surface area to fulfill the requirements in a better way around. Solar panels generate energy efficiency from 11% to 15%, this is the percentage of solar energy which are transformed into functional electricity. The developments and advancements have been made to fulfill the requirements to meet household and profit-oriented needs.


Researchers are working very hard to upgrade the efficiencies of Photovoltaic technology. They have managed to achieve 40% efficiency with aid of multi-function cells which are later transformed to apprehend divergent frequencies of light within the spectrum of electromagnetic. Although, the large area can create less efficient energy and less expensive panels may save the costs of installation. We have shown above the process efficiency calculation and you can find your answer that how to calculate solar panel efficiency.


The future of solar panel efficiency will greatly impact massive competition in the market of solar panels. The competition may lead to lessening the prices of solar panels and will effectively generate efficient storage solutions. The solar panel grants are motivating households to install renewable energy conversion panels to generate electricity to complete important tasks or electrical load demands.

The researchers have stated that enhancing the rate of photovoltaic conversion efficiency helps to provide better energy out of solar power. Many businesses are taking measures to maintain and achieve maximum solar efficiency which helps to maintain optimal performance levels and saves time and money. The future solar panel efficiency partially depends on updated technology and research. Best research and technology can give us highly efficient solar cells. However, we have given a simple calculation process to clarify how to calculate solar panel efficiency.

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