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Photovoltaic Generation Forecasting Using Weather Forecast and Predictive Sunshine and Radiation

일기 예보와 예측 일사 및 일조를 이용한 태양광 발전 예측

  • 신동하 (가천대학교 에너지 IT학과) ;
  • 박준호 (가천대학교 에너지 IT학과) ;
  • 김창복 (가천대학교 에너지 IT학과)
  • Received : 2017.11.08
  • Accepted : 2017.12.29
  • Published : 2017.12.31

Abstract

Photovoltaic generation which has unlimited energy sources are very intermittent because they depend on the weather. Therefore, it is necessary to get accurate generation prediction with reducing the uncertainty of photovoltaic generation and improvement of the economics. The Meteorological Agency predicts weather factors for three days, but doesn't predict the sunshine and solar radiation that are most correlated with the prediction of photovoltaic generation. In this study, we predict sunshine and solar radiation using weather, precipitation, wind direction, wind speed, humidity, and cloudiness which is forecasted for three days at Meteorological Agency. The photovoltaic generation forecasting model is proposed by using predicted solar radiation and sunshine. As a result, the proposed model showed better results in the error rate indexes such as MAE, RMSE, and MAPE than the model that predicts photovoltaic generation without radiation and sunshine. In addition, DNN showed a lower error rate index than using SVM, which is a type of machine learning.

무한한 에너지원을 가진 태양광 발전은 기상 에 의존하기 때문에 발전량이 매우 간헐적이다. 따라서 태양광 발전량의 불확실성을 줄이고 경제성을 향상시키기 위하여 정확한 발전량 예측기술이 필요하다. 기상청은 3일간 기상정보를 예보하지만 태양광 발전 예측에 높은 상관관계가 있는 일조량과 일사량은 예보하지 않는다. 본 연구에서는 기상청에서 3일간 예보하는 기상요소인 기온, 강수량, 풍향, 풍속, 습도, 운량 등을 이용하여, 일조 및 일사량을 예측하였으며, 예측된 일사 및 일조량을 이용하여, 실시간 태양광 발전량을 예측하는 딥러닝 모델을 제안하였다. 결과로서 예측된 기상요소로 발전량을 예측하는 모델보다 제안 모델이 MAE, RMSE, MAPE 등의 오차율 지표에서 더 좋은 결과를 보여주었다. 또한, 기계 학습의 한 종류인 서포트 벡터 머신을 사용하는 것보다 DNN을 사용하는 것이 더 낮은 오차율 지표를 보여주었다.

Keywords

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