Energy, exergy, emergy, and economic evaluation of a novel two-stage solar Rankine power plant.

This paper studies a solar-powered organic Rankine cycle-integrated cooling and electricity co-generation system. This system consists of a steam cycle, an organic Rankine cycle, the parabolic trough solar collectors' field, and a gas turbine cycle as well as a cooling heat exchanger for the co-production of power and cooling. The steam generator in this cycle is a dual pressure system that works with the thermal energy received from the solar collectors. The proposed process is analyzed thermodynamically and economically using the novel emergoeconomic approach. Then, to find the optimum operating parameters of the power plant, multi-objective optimization is performed by implementing the novel water cycle algorithm. The objectives of this optimization process are to maximize the system's efficiency and to minimize the monetary emergy rate of the products. This study shows an increase of 8% in the exergy efficiency (from 40.2 to 48.2%) after the optimization. The production cost decreased by 6.1% from 18.8 to 17.6 USD/GJ, and the emergoeconomic rate decreased by 18.9% from 27.1 to 22 sej/s. Furthermore, the power production in the proposed cycle compared to the base cycle increased by 111.7 MW in the gas cycle and 39.4 MW in the steam cycle.