Power

The power of a solar system refers to its ability to convert solar energy into electrical energy. It is expressed in kilowatt-peak (kWp) and indicates the maximum electrical power that a system can generate under standardized test conditions (STC). These conditions include a specific irradiance, temperature, and spectral composition of sunlight.

Key aspects of power:

• Nominal power: The nominal power corresponds to the kWp rating and is an important value when sizing a PV system. It indicates the maximum theoretical power that can be achieved under optimal conditions.
• Actual power: The actual electrical power generated, which is fed into the grid or used for self-consumption, is referred to as actual power. It is usually lower than the nominal power, as real conditions (weather, module contamination, etc.) deviate from the STC.
• Power degradation: Over the lifetime of a PV system, power decreases due to aging and contamination of the modules. This power degradation is expressed as a percentage per year and is an important factor in economic calculations.
• Power factor: The power factor describes the ratio of actual power to apparent power. A high power factor is desirable, as it allows for a more efficient use of electrical energy.

Factors influencing power:

• Solar irradiance: The intensity and angle of solar radiation have a decisive impact on the yield of a PV system.
• Temperature: High temperatures can reduce the power of solar modules.
• Shading: Shading from trees, buildings, or other obstacles reduces the power of the affected modules.
• Module quality: The quality of the solar modules affects the power and lifespan of the system.

Relevant keywords: Kilowatt-Peak (kWp), Nominal Power, Actual Power, Solar Irradiance, Shading, STC (Standard Test Conditions)