Effect of Distributed Solar Energy Generation on Uganda's Electricity Grid Stability

Solar energy technology provides power and is only used when there is availability of the resource. However, large amount of solar energy is difficult to integrate into the grid because its availability is constantly changing and uncertain. The assessment aimed at establishing the extent to which an alternative solar plant would be able to support other intermittent solar generation on the grid. Generation possibilities like synchronization and asynchronous variations with no battery storage were evaluated using MATLAB Simulink. The grid voltage, grid current, real power, grid frequency and reactive power were monitored for the generation scenarios. For the scenarios of asynchronous generation, the grid behaved in the same way as though the generation was lumped at one location. This was a consistent observation since the reactive power support was still coming from the base hydro-generation plant. For synchronized distributed generation (60 MW and 10 MW of solar), reactive power was still available on the grid. Synchronization was used to integrate solar plants into the grid without requiring any further grid support. However, in this option, a deliberate investment must be made in a control system to support site synchronization. Precise controllers were required to send a real-time generation to alternate locations so that the reserves could be ramped up to restore stability.