Kilowatt Peak

kilowatt peak (kWp) is a specific unit of measurement used in photovoltaics to indicate the maximum electrical power of solar panels under standard test conditions (STC). These conditions include a specific irradiance, a temperature of 25°C, and a specific air mass.

The "p" in kWp stands for "peak" and refers to the peak power that a module can deliver under optimal conditions. It is important to note that the actual energy produced by a photovoltaic system depends on various factors, such as:

  • Weather conditions: solar irradiance, temperature, cloud cover
  • Orientation and tilt of the modules: optimal orientation towards the sun
  • Shading: from buildings, trees, or other objects
  • Ageing of the modules: performance decline over time

Why is kWp important?

  • Comparability: kWp allows for a direct comparison of different solar panels.
  • Design of systems: The total power of a photovoltaic system is expressed in kWp and is crucial for sizing the system.
  • Cost calculation: The costs of a photovoltaic system often depend on the installed capacity in kWp.

Example: A solar panel with a power output of 300 watts peak can produce a maximum of 300 watts of electrical power under optimal conditions. A photovoltaic system with a total capacity of 5 kWp consists of several modules that can collectively deliver a maximum output of 5000 watts.

Important distinction: kWp vs. kWh

  • kWp: Maximum possible output of a module or system under standard conditions.
  • kWh: The amount of energy produced over a specific period. 1 kWh corresponds to the power of 1 kW over one hour.

Conclusion: Kilowatt peak is an important metric in photovoltaics to describe the performance of solar panels and systems. It enables comparison and planning of photovoltaic systems. However, it is essential to understand that the actual energy produced depends on various factors and is often less than the theoretical peak output.

Relevant keywords: solar panels, solar system, power, standard test conditions (STC), solar irradiance, kilowatt-hour (kWh)