A new analysis for a concentrated solar power-based cogeneration system with molten salt energy storage and heat recovery steam generator – Case study – (USA, France, Canada)

Abstract

This study sought to determine an optimal scenario concerning multiple climatic parameters to maximize the performance of a solar system. A molten salt energy storage unit was used to enable round-the-clock power generation and maximize the system's reliability. A solar concentrator with heliostats and a solar receiver was employed to absorb solar energy, and a modified steam Rankine cycle was utilized to generate power. A total of 12 scenarios were evaluated based on three climatic parameters (ambient temperature, sunshine duration, and wind speed) and one techno-economic parameter (number of heliostats). Sankey analysis, which is a novel technique used to determine the optimal scenarios in the literature, revealed that Scenario 8 was optimal. This scenario showed the maximum exergy rate, minimum exergy destruction, and lowest cost rate. This scenario considered the sunshine duration of 11 h, ambient temperature of 16 °C, wind speed of 3 m/s, and 300 heliostats, resulting in output energy of 1582 kWh and exergy destruction of 34250 kWh. The parametric analysis showed that the turbine and superheater temperatures had the greatest effects on the system performance. The exergy analysis of the system demonstrated that the heliostats and solar receivers accounted for the largest portions of exergy destruction. Multi-objective optimization via response surface method yielded the optimal exergy round-trip efficiency of 11.5% and optimal cost rate of 229.2 $/h. The economic analysis of the system revealed that the solar subsystem had the highest cost rate. In terms of efficiency and production power, this system will perform differently in different parts of the world and under different weather conditions. To this end, it is important to find out where this particular system will be more efficient and powerful. Six different scenarios have been defined for the parametric analysis of the proposed system in order to achieve reliable results. For the case study, Los Angeles and San Diego were selected as the regions with the highest similarity to the optimal scenario in terms of sunshine duration, ambient temperature, and wind speed, whereas Paris and Toronto were randomly selected. The performance of the system showed that the system can produce 2612.3 megawatts of electricity in the city of San Diego and 2472.4 megawatts of electricity in the city of Los Angeles. Also, by setting up this system, it is possible to provide electricity for 51 to 54 residential units. The proposed system performed better in regions with climatic parameters similar to those in the optimal scenario.