A simulation tool for concentrated solar power based on micro gas turbine engines

Abstract In the scenario of the small scale 3–35 kWe concentrated solar power plant based on point receiver technologies, the dish-Stirling configuration is one of the most commonly adopted one. New and clean efficiency of these Stirling engines is typically of 30–40%. Yearly average efficiency, during the system operations, is significantly reduced to 10–15% due to the Stirling engines high maintenance costs and poor reliability issues. These drawbacks limit the small scale dish-Stirling engines market attractiveness. The adoption of cheap, reliable and widely available engines, such as micro gas turbines is a promising solution for substituting Stirling engines since it ensures constant performance over time. Since micro gas turbines for concentrated solar power plants equipped with dish concentrator have not been widely deployed, the development of a plant simulator is helpful for predicting the overall concentrated solar power plant performance and for optimizing the plant operations under different boundary conditions. The plant simulator is aimed to demonstrate the economic viability and the technical feasibility of dish-micro gas turbine systems. The paper includes the methods for developing a simulation tool for solar dish – micro gas turbine applications. The solar concentrator, receiver/absorber, micro gas turbine, high speed generator and power electronic systems have been modelled and the plant simulator has been set-up by means of a quadratic programming technique. The simulator has been used to perform steady state simulations for predicting the performance and for ensuring a safe and reliable power plant operation when the direct normal irradiation changes. The results for a net generated power of about 6 kWe have shown a nominal peak efficiency of about 10%, making this micro gas turbine solar plant layout market attractive.