Evaluation of WRF model-derived direct irradiance for solar thermal resource assessment over South Korea

• Main Authors: Kim, Jin-Young, Yun, Chang-Yeol, Kim, Chang Ki, Kang, Yong-Heack, Kim, Hyun-Goo, Lee, Sang-Nam, Kim, Shin-Young
• Format: Conference Proceeding
• Language: English
• Subjects: Cloud cover; Ground stations; Irradiance; Sky; Solar heating; Uncertainty; Weather forecasting
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4984521

The South Korean government has been started monitoring and reassessment for new and renewable resource under greenhouse reduction related with the climate agreement in Paris. This study investigated characteristics of the model-derived direct normal irradiance(DNI) using ten-minute data of the Weather Research and Forecasting(WRF) model with 1 km grid spacing. First, ground horizontal irradiance(GHI) and direct normal irradiance(DNI) from the model was compared with those of ground stations throughout South Korea to evaluate the uncertainty of the GHI-derived DNI. Then solar thermal resource potential was assessed using a DNI map. Uncertainty of irradiances appeared highly dependent on sky conditions. Root mean square errors in DNI(GHI) was 45.39%(18.06%) for all sky with the range of 9.92∼51.93%(14.49∼51.47%) for clear to overcast sky. These indicate DNI is further sensitive to cloud condition in Korea which is around 72% of cloud days during a whole year. Finally DNI maps showed high value over most areas except southeastern areas and Jeju island which is humid regions in South Korea.