報告書番号

V12015

タイトル（和文）

太陽光発電のための日射量予測の信頼性指標

タイトル（英文）

Reliability Indicator of Solar Radiation Forecast for Photovoltaic Power Generation

概要 （図表や脚注は「報告書全文」に掲載しております）

太陽光発電は，日射変動の影響で発電量が不安定になることから，電力の安定供給や効率的な需給運用のためには，日射量を高い精度で予測することが求められている．日射量予測の信頼性の指標は，大気の力学的に不安定な性質に基づき，アンサンブル予測のスプレッドの大きさとして推定される．本研究では，気象庁が提供する週間アンサンブル予報を利用して，関東を対象とした日射量予測の信頼性指標を評価した．予測の信頼性は，低気圧や低気圧に付随した前線などの擾乱が通過する場合に低下する傾向にある．また，信頼性指標は，予測対象日の一週間前からの性質が持続する特徴も見られた．この信頼性指標と，気象予測・解析システムNuWFASによる日射量予測結果と比較したところ，予測の信頼性が低い（高い）と推定された事例では，NuWFASの予測誤差も大きい（小さい）傾向にあった．

概要 （英文）

Photovoltaic power generation is an inherently unstable energy source as it is affected by fluctuations in solar radiation, and hence, accurate and reliable solar radiation forecasts are essential for maintaining a stable power supply, ensuring efficient operation, and avoiding wider reaching negative effects associated with forecast errors. The reliability indicator of the forecast can be estimated using the magnitude of an ensemble spread based on dynamically unstable characteristics of the atmosphere. In this study, we validated the reliability indicator of the forecast for the Kanto region using weekly ensemble forecasts provided by the Japan Meteorological Agency. The results showed that forecasts were less reliable during the passage of extra-tropical cyclones and their accompanying fronts. Furthermore, the reliability indicators for the forecast on the following day were roughly correlated with those from the previous week. The reliability of the forecast was compared with a solar radiation forecast using the Numerical Weather Forecasting and Analysis System (NuWFAS), and it was confirmed that less (more) reliable forecasts roughly corresponded to large (small) errors in the solar radiation forecast from NuWFAS.

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