Short-term solar forecasting for microgrids

This thesis explores the need and application of short-term solar forecasting (STSF) in microgrids. Among several solar forecasting methods, a justification for the choice of sky imaging tools as a preferred method for STSF in microgrids is provided. The rapid increase in the uptake of solar PV in the electricity grid has shown a convergence in research in the fields of solar forecasting and management of the electricity grid. This energy transition from fossil fuel powered generation to renewable energy generation characterised by consumer-controlled energy generation and the emergence of smart grid has created a surge in demand for real time solar PV forecast information. The relationship between short-term solar forecasting information and microgrid PV generation fluctuation is analysed together to identify areas for the application of STSF technique in microgrid management. To achieve this, the various solar forecasting methods are discussed with a view of identifying suitable techniques for microgrid applications. Sky imaging is identified as a preferred method thus the operation principle of a sky imaging tool is explained followed by analysis of capabilities of several tools/products available in the market. A summary chart showing the capabilities of WobaS, Steady eye, Instacast and CloudCAM STSF tools is presented in a table. Three case studies are selected to demonstrate the need and application of STSF under the following scenarios: • Case 1: Uncontrollable distributed energy resource for this case solar PV, together with centrally located fossil fuel powered power plant with no STSF tool in use. • Case 2: Centrally located and controllable solar PV plant, a central fossil fuel power plant and energy storage using STSF tool. • Case 3: Virtual power plant using STSF tool. Through this approach the need, application and associated benefits of STSF is clearly shown. The benefits in cost savings for the combination of STSF with battery storage is demonstrated. Overall this thesis connects STSF and microgrid management