9:30 AM - 9:45 AM
[HRE18-03] Evaluation of Cloud locations with Stereo Observations for predicting solar PV temporal variation
Keywords:Solar photovoltaic power generation, Stereo measurement, Clouds
Photovoltaic (PV) power generation is one of important renewable energy, and it has been getting more poplar and numbers of both mega-solar PV and small scale solar PV systems have been rapidly increasing these days. While the solar PV is a common renewable energy source, it is difficult to predict temporal variation of power generation accurately depending on weather conditions. Especially it has been reported that passing of patchy clouds makes the prediction more difficult (Itagaki et al., 2011, 2012). The difficulty is from both weather forecast and observation issues. Because the grid interval of current weather forecasting is the order of 1 km, it has not been able to resolve sub-km scale cloud distributions which can affect variation of local solar PV power generation. The typical spatial resolution of geostationary satellites, such as Himawari-8, is 500m - 1km size, which is also not enough to resolve the small-scale cloud structures.
To have better spatial resolution for cloud observation, we have planned to develop a cloud monitoring system constructed with multi (more than three) wide field of view (FOV) cameras, the interval of each camera is a few hundred meters. The interval allow us to measure cloud locations with a stereo estimation method for the clouds from several km to ten km altitudes. In addition, current wide FOV cameras allow to resolve cloud position with a smaller resolution than 100m.
In this study, to demonstrate the stereo measurement can work for clouds at the first step, we set two cameras with ~400m interval and took images which satisfied stereo condition for several to ten km altitude clouds. The camera orientation and the amount of tilting were measured with star position measurement in the camera images, which is a common technique for determining a satellite attitude in space with less than 0.1 degree accuracy, and it takes no additional cost. From the stereo measurement, we have successfully resolved cloud positions whose altitudes were from 1,300m – 2,500m, and also we have resolved cloud motions from sequential observation images. In this presentation, we will introduce our approach for measuring three dimensional cloud positions and its results, and we will discuss predicting temporal variation of solar PV power generation with the cloud positions and the cloud motions.
To have better spatial resolution for cloud observation, we have planned to develop a cloud monitoring system constructed with multi (more than three) wide field of view (FOV) cameras, the interval of each camera is a few hundred meters. The interval allow us to measure cloud locations with a stereo estimation method for the clouds from several km to ten km altitudes. In addition, current wide FOV cameras allow to resolve cloud position with a smaller resolution than 100m.
In this study, to demonstrate the stereo measurement can work for clouds at the first step, we set two cameras with ~400m interval and took images which satisfied stereo condition for several to ten km altitude clouds. The camera orientation and the amount of tilting were measured with star position measurement in the camera images, which is a common technique for determining a satellite attitude in space with less than 0.1 degree accuracy, and it takes no additional cost. From the stereo measurement, we have successfully resolved cloud positions whose altitudes were from 1,300m – 2,500m, and also we have resolved cloud motions from sequential observation images. In this presentation, we will introduce our approach for measuring three dimensional cloud positions and its results, and we will discuss predicting temporal variation of solar PV power generation with the cloud positions and the cloud motions.