Multi-layer wind velocity field visualization in infrared images of clouds for solar irradiance forecasting
Abstract
The energy available in a solar energy powered grid is uncertain due to the weather conditions at the time of generation. Forecasting global solar irradiance could address this problem by providing the power grid with the capability of scheduling the storage and dispatch of energy. The occlusion of the Sun by clouds is the main cause of instabilities in the generation of solar energy. This investigation proposes a method to visualize the wind velocity field in sequences of longwave infrared images of clouds when there are multiple wind velocity fields in an image. This method can be used to forecast the occlusion of the Sun by clouds, providing stability in the generation of solar energy. Unsupervised learning is implemented to infer the distribution of the clouds' velocity vectors and heights in multiple wind velocity fields in an infrared image. A multi-output weighted support vector machine with flow constraints is used to extrapolate the wind velocity fields to the entire frame, visualizing the path of the clouds. The proposed method is capable of approximating the wind velocity field in a small air parcel using the velocity vectors and physical features of clouds extracted from infrared images. Assuming that the streamlines are pathlines, the visualization of the wind velocity field can be used for forecasting cloud occlusions of the Sun. This is of importance when considering ways of increasing the stability of solar energy generation.
- Publication:
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Applied Energy
- Pub Date:
- April 2021
- DOI:
- arXiv:
- arXiv:2012.02861
- Bibcode:
- 2021ApEn..28816656T
- Keywords:
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- Cloud tracking;
- Machine learning;
- Flow visualization;
- Beta mixture model;
- Sky imaging;
- Solar forecasting;
- Electrical Engineering and Systems Science - Image and Video Processing
- E-Print:
- doi:10.1016/j.apenergy.2021.116656