How to calculate the efficiency of Solar Modules?

Solar panels can typically convert 15% to 22% of solar energy into usable energy, depending on factors such as installation, orientation, weather conditions, and so on. The quantity of sunshine that solar panel systems can convert into actual power is referred to as performance, and the outcome defines solar panel efficiency.

Solar panels are tested at Standard Test Conditions to assess their efficiency (STC). The temperature of 25°C and irradiance of 1,000 W/m 2 are specified by STC. This is the equivalent of a sunny day with incident light striking a 37°-tilted surface facing the sun. A solar panel efficiency of 15% with a 1 m 2 surface area would produce 150 Watts under these test conditions.

To begin, it is very important to know that the efficiency of a solar panel is determined by its area rather than its power. A 10% efficiency 100W panel and a 20% efficient 100W panel will both output the same amount of power. However, the 20% efficient solar panel should be half the size of the 10 percent efficient panel.

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To calculate the efficiency of the panel, we must compare the power supplied by the sun to the electricity produced. If a panel could convert all of the light that fell on it into power, it would be 100%. Unfortunately, such efficiency is not achievable.

A solar cell composed of perfect material has a theoretical maximum efficiency of 33.7%. This is known as the Shockley-Quiesser limit, resulting from physical principles and how solar cells absorb electricity. Multi-layered solar cells can reach this limit in lab settings, but they are substantially more difficult to build and much more expensive, thus they are normally reserved for satellites and other high-tech devices with limited space.

The theoretical limit for silicon solar cells (the type found in practically every panel available) is roughly 32% because silicon, while close, is not a perfect solar cell material.

When opposed to this, general-purpose solar cells will always lose some power and can only attain a maximum efficiency of up to 25% in perfect conditions. Because of the frame, reflective metal connections, and gaps between the cells, the efficiency of a panel as a whole will always be lower than the efficiency of its component cells.

To begin comparing the sun’s power to the panel’s electricity output, we must first understand the power of the sun. At midday near the equator, each square meter of the earth receives somewhat more than 1kW (1000W) of sunlight.

Away from the equator, and depending on the season, weather, and time of day, this will be less, however, the 1kW per square meter value is used for testing panels to determine the power rating they are marketed with. This is part of the standard test conditions (STC) used by the solar power industry, and all panels are graded in the same way.

Consider a 1 square meter panel. If it produced 1kW of electricity at midday on the equator, we could say it was 100% efficient since it would receive 1kW of sunlight and convert it into the same amount of electricity.

If a panel of the same size produced 200W of power instead, the efficiency is 200W/1000W x 100 = 20%.

To make this computation, we need to know the area of any solar panel that isn’t 1 square meter. A panel that is half the size and provides the same amount of power is twice as efficient, and vice versa.

By multiplying the width by the length of the panel, the area may be simply computed. Remember to first convert the dimensions into meters because areas do not convert in the same manner as lengths.

Finally, to compute the maximum efficiency of a solar panel, divide the ratio of panel power to solar power by the area of the panel in square meters, then multiply by 100. Check that the measuring units for all the data are correct, or you will get unusual results.

Navitas Solar has launched its Bonito Series of solar Modules that have more than 21% efficiency. For example, Bonito Max 10 BB 144 cell modules are having dimension of 1134 mm*2278 mm (W*L) and generates 560 watts per panel. So, to calculate the efficiency it will be like

=21.67%

Bonito Pro 144 Cell / 9 BB Module: 21.47%

Bonito Pro 156 Cell / 9 BB Module: 21.36%

Bonito Max 144 Cell / 10 BB Module: 21.67%

Bonito Max 156 Cell / 10 BB Module: 21.64%

In terms of performance and reliability, Navitas Solar Modules are the best in class. To offer the best value for money, we manufacture all of our solar modules using high-quality raw materials. Because of our rigorous product design and stringent quality control, our modules produce an incredibly high PV yield.