Formula to calculate solar panel efficiency

Here is how to calculate solar panel efficiency that we often give quick instructions for customers, you can refer to:

What is solar cell center efficiency?

Solar cell efficiency is the ratio between electromagnetic energy and sunlight energy. Using a method of measuring the amount of sunlight the solar battery system can actually convert into electricity. In addition to reflecting the efficiency of the solar cell itself, the efficiency also depends on the spectrum and intensity of the incident sunlight and the temperature of the solar cell.

Formula to calculate solar panel efficiency

Solar panel efficiency (in %) is the ratio of the maximum capacity of the panel (at STC condition) divided by the surface area of the solar panel.

η=Pmax/S×100%

In there:

η: Efficiency of solar panels

Pmax:Maximum power of panels at STC condition (kWp)

S: Solar panel area (m2)

Practical example:
Canadian Solar panels code CS3W-450MS

According to the documentation of the battery, we have:

Pmax = 450 W = 0,45 kW

S = 2,1081,048 = 2,21 m2

η=  20,36% ~ 20,4%

Thus, with panels of the same capacity, panels with high efficiency will save installation space.

Fatal mistakes about solar cell center efficiency

- Panels with higher capacity have greater efficiency:

In fact, many customers misunderstand that panels with higher capacity have higher efficiency. The following example illustrates that misunderstanding.

The 370W power panel has an efficiency of up to 21.4% (very high current) far superior to many panels with a capacity of 430-500W.

- Panels with higher efficiency, better quality:
The quality of panels depends on many factors, the efficiency of the panels is also a reference parameter. However, it is not entirely accurate to conclude that the panel has higher efficiency than better quality.

Intech Energy is one of the prestigious EPC general contractors in the field of providing installation solutions, supplying materials and constructing and installing solar power projects nationwide ranging from households to large scale projects. for Business. We have more than 10 years of working experience in the solar power and renewable energy industry, always committed to giving dedicated advice to our customers to provide effective solutions with quality products, competitive prices, and competitive prices. Sustainable development of clean energy sources to "Create a green life".