Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations

Figure 2

Yearly energy yield losses of a 1 kWp PV system at HTW Berlin, Germany, for various inverter sizing factors (the relation between installed PV power on the DC side and nominal AC inverter output) and a maximum power clipping value of 70% (output power is cut at 70% of the installed DC power). Using hourly averaged values for the simulation of PV systems leads to a significant underestimation of the yearly yield losses. With hourly averaged values (grey), the total energy loss is at 1.3% while the more precise simulation with one-minute values (blue) returns a total energy loss of 3.9%. In addition, this figure illustrates that the optimal inverter sizing factor (here, 143%) for systems with maximum power clipping is the reciprocal of the clipping value (70%).