Sizing of PV-system increases yield dramatically

Correct sizing of PV system is important for increasing yield

What is the DC-AC ratio of solar panels connected to an inverter? Within the design of a PV system, the capacity of the solar panels exceeding the capacity of the inverter is called oversizing. Reasonable over ratio design can significantly optimize inverter yields, reduce AC side equipment costs and increase overall efficiency.

Why is oversizing necessary?

The nominal power of the solar panels is the maximum output under ideal conditions in a test laboratory. However, in normal life circumstances appear to be more complex, the weather is not a constant, so the output power of panels is always variable. Due to many factors, losses inevitably occur which will cause the output power of the panels to be lower than the rated power tested. If you would you like to know more about the factors that can affect the output power of modules, such as

  1. The sun as an energy source
  2. Degradation of solar panels
  3. The angle of the solar panel
  4. Other factors


Summary: This article demonstrates that the actual output power of the modules is lower at their nominal power. In order to improve the utilization rate of the inverter, it is considered good practice to use DC side oversizing. Using the NREL-SAM simulation example, the data proves that increasing the DC-to-AC ratio will result in higher power generation. Although there may be a loss through clipping, the increase in power generation of the system is always greater than the loss caused by clipping.The optimum ratio of direct current (DC) to alternating current (AC) ) requires a full consideration of the benefits of system power generation, system installation costs, operation and maintenance costs, and overall system production (loss of module production and mismatch effects associates etc.), in order to strike a balance between the increased costs by over-sizing on the DC side and the revenue gains generated by the electricity production of the system. Reasonable DC to AC ratio can increase system profits, reduce system cost per kilowatt hour, and maximize overall profits.

Please read the full paper on sizing.