| Summary: | Solar intermittency is a critical issue which limits the development of grid-connected
photovoltaic system in the applications of solar energy. High accuracy of solar
irradiance forecasting plays an important role in establishing modern photovoltaic
generation power system. With the prediction data provided, the system will take
appropriate actions to control the energy storage system. This thesis focuses on one of
the methods of short-term solar irradiance forecasting based on ground-based sky
imager, i.e. sky images captured by Total Sky Imager (TSI) and Wide Angle High-
Resolution Whole Sky Imaging System (WAHRSIS). The images obtained will be
processed to determine the cloud cover and analyzed to estimate the cloud motion
velocity by using the MPIV algorithm. The cloud condition of next few minutes will
be predicted and consequently the solar irradiance values can be calculated based on
the program developed in this project. The sample results taken in this project show
that the program in this project can forecast the solar irradiance in specific location for
about 5-15 minutes with mean prediction error about 20%. The intra-hour solar
irradiance can be obtained by consecutively collecting images into the program.
Depending on different locations and sky imager systems, the same algorithm can be
applied accordingly by calibrating the threshold value for cloud determination and
image resolution to forecast the solar irradiance.
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