Development and Practical Use of Prediction System for PV Output in an Electric Power Company in Japan

Photovoltaic systems (PV) are rapidly introduced in Japan. Since their output changes depending on weather conditions, supply and demand control of the electric power system is becoming difficult. Based on this background, we developed a prediction system of PV output to help the controlling and planning in electric power company (Table 1) [1]. This system has the feature of the hybrid system, because it predicts a PV output by combining numerical weather forecast and satellite cloud images. Our system was put into practical use for the first time in a Japanese major electric power companies [2]. We introduce a detail of prediction method and prediction accuracy in this paper.