観測地点周辺の平滑化効果を考慮した中部全域における空間平均日射変動特性 Spatial Average Irradiance Fluctuation Characteristics in Chubu Region Considering Smoothing Effect around Observation Points

For the impact assessment of high-penetration photovoltaic power generation systems (PVS) on the electric power system, the proper estimation of total power output fluctuation of PVS is essential, considering the so-called smoothing effect among a number of PVSs. By using the irradiance data observed at 61 points for a year, this study statistically evaluated the fluctuation characteristics of spatial average irradiance in the Chubu region, Japan. The smoothing effect around individual observation point was taken into account by using a low-pass filter developed based on the so-called transfer-hypothesis. Main results are as follows. The absolute value of the maximum fluctuation width (MFW) calculated with 120min window is around 350W/m<SUP>2</SUP> on many days due to the sunrise or sunset. The MFW of sun-position independent spatial average irradiance is sometimes larger than 300W/m<SUP>2</SUP> and occurs before or after the noon due to the coherent change of weather condition over the region. The MFW of spatial average irradiance tends to be large in the summer season, while the MFW of clearness index tends to be large in winter season. The hourly standard deviation of fluctuation including cycles shorter than 32min is a few percentage of hourly average irradiance.