A Comparative Thermoeconomic Study of Hybrid Solar Gas-Turbine Power Plants

The construction of the first generation of commercial hybrid solar gas-turbine power plants will present the designer with a large number of choices. To assist decision making, a thermoeconomic study has been performed for three different power plant configurations, namely, simple- and combined-cycles along with a simple-cycle with the addition of thermal energy storage. Multi-objective optimization has been used to identify Pareto-optimal designs and highlight the trade-offs between minimizing investment costs and minimizing specific CO2 emissions. The solar hybrid combined-cycle power plant provides a 60% reduction in electricity cost compared to parabolic trough power plants at annual solar shares up to 20%. The storage integrated designs can achieve much higher solar shares and provide a 7-13% reduction in electricity costs at annual solar shares up to 90%. At the same time, the water consumption of the solar gas-turbine systems is significantly lower than conventional steam-cycle based solar power plants.