PV System Efficiency

Factors Affecting PV System Efficiency

In the world of solar energy, it's essential to understand that the process of converting sunlight into electricity is not completely efficient. Various environmental factors and losses within the system's components can impact the overall efficiency of a photovoltaic (PV) system.

Typical loss categories include:

Temperature: The efficiency of a solar panel varies with temperature. High temperatures have a negative impact on performance.

Soiling: Material that accumulates on the surface of PV panels can block light from reaching the solar cells, thereby reducing the generated power. The power loss due to soiling is highly variable, depending on the type of soiling (such as dust or snow), and how frequently the panel is cleaned.

Shading: Shading is the obstruction of irradiance due to trees, buildings, terrain, and other objects in the environment. The effect of shading on the power output of a solar installation is highly variable. To understand the causes and consequences of shading, as well as strategies to reduce shading losses, please visit this article.

Wiring and connections: Resistance in the electrical connections of a solar installation typically results in energy losses of a few percent.

Mismatch: Due to manufacturing variations, modules of the same type can have slightly different electrical characteristics. This mismatch between modules can lead to a performance loss.

Inverter Efficiency: The process of converting direct current (DC) to alternating current (AC) in inverters is about 96-97% efficient. Efficiency is higher when DC input power is close to the inverter’s rated power.

Age: Solar panels produce less energy the older they get. Typically the decrease in performance is assumed to be around 0.5% per year.

To learn more about PV losses, download the PV Losses ebook.