Calculating the efficiency of a solar panel is a complex process.
Choosing the elements of your solar power system might be complicated by concerns regarding the solar panel's efficiency. A solar energy calculator is the most ideal way to gauge the efficiency of a panel.
However, it can help to understand the process yourself as well, to smoothen your journey towards adopting solar energy. Everything you need to know about solar panel efficiency is explained in detail in this article.

Calculating Efficiency As A Percentage

Calculating a solar panel's efficiency as a percentage may be done using the following formula:

Efficiency = (Panel Power in kW/Panel Length x Panel Width in m) x 100

The results may give you a decent glance at the efficiency of a panel. But, for more comprehensive and accurate insights, a state-of-the-art solar panel calculator is your best bet.

It is vital to emphasize that the efficiency of a solar panel is a function of its area, not its output. There is no difference in the quantity of electricity generated by a 10% efficient and a 20% efficient 100W panel. However, you should anticipate a 20% efficient solar panel to be half the size of a 10% efficient panel in terms of overall size.

To calculate the panel's efficiency, we must compare the amount of power provided by the sun to the amount of energy generated. In order for a solar panel to be 100% efficient, it must be capable of converting all of the light falling on it into power. This degree of effectiveness is, unfortunately, unattainable.

What Is The Maximum Possible Efficiency Of A Solar Cell?

For a solar cell built of all the right materials, the maximum theoretical efficiency reflected on a solar panel calculator is 33.7%. Owing to the laws of physics and the way solar cells absorb energy, and the Shockley-Quiesser limit, we've reached this point.

Due to their complexity and high cost, multi-layered solar cells may go beyond this limit in the lab. However, in real-world applications, they are reserved for satellites as well as other high-tech devices with very restricted surface area.

If you're using a silicon solar cell, the potential limit is around 32% since silicon, albeit near, does not have the ideal solar cell properties. When comparing mass-market solar cells with this, it is impossible to attain more than a maximum of 25% efficiency. It is impossible for a panel to be more efficient than the sum of its individual cells. This is because of the frame, reflective metal connections, and gaps between them.

The Sun’s Power and The Electricity Output of The Panel

We must first determine the power of the sun in order to compare it to the panel's electrical production.
It takes little over 1kW of sunshine to illuminate a square meter of the earth at noon near the Equator. The 1kW per square meter number is used when testing panels to provide the power rating they are advertised as. However, it will be less as we move farther from the equator and in various seasons, weather conditions, and times of the day.

In the solar power business, this is one of the standard test conditions (STC), and all panels are graded in the same manner before testing their efficiency through a solar energy calculator.

Imagine a one-square-meter-sized panel on your rooftop. One kilowatt at noon on the equator would indicate that the solar panel was 100% efficient, given that the same quantity of sunlight it received would be converted to energy. Its efficiency would be 20% if a panel the same size provided 200W of electricity instead.

Since 0.2kW/1kW = 0.2, we may omit the sun's output when expressing this in kilowatts, making the equation even simpler. To get a percentage, multiply the ratio by 100.

We need to know the panel's area in order to do this computation for any solar panel larger than 1 square meter. A panel that is half the size and generates twice as much electricity is more efficient. Multiplying the panel's width and length yields the panel's surface area.

Quick Tip:Before you begin, remember to convert the measurements into meters, since areas are not converted the same way as lengths are! That is, 1000 square millimetres do not form 1 square meter- 1 million square millimetres do.

Finally, to compute the solar panel's maximum efficiency, we divide the ratio of solar panel power to sun power by the panel's size in square meters, then multiply by 100 to obtain a percentage. Make sure all the numbers are in the right measurement units or you'll get highly unpredictable results.

Conclusion

Governments, corporations, and people may use rooftop solar panels to help them achieve environmental sustainability objectives. Utilizing cutting-edge space, geospatial, and utility-industry technologies, our solar energy calculator provides exact statistics to help you make an educated choice about switching to solar energy.