Proposal and ANN-assisted optimization of a hybrid solar- and biomass-based energy system for electricity, freshwater, and hydrogen production

The present work introduces a new integrated system for higher penetration of renewable energy in local energy grids, flattening the peak load, dealing with worldwide energy demands, and slowing climate change by reducing carbon dioxide emissions. The idea involves solar and biomass combination through high-temperature parabolic solar collectors and a gasifier unit for clean heating production with minimal emission and the highest reliability. The system also has Rankine and Organic Rankine cycles for efficient power generation. Additionally, the surplus heat is exploited via a multi-stage flash desalination unit and absorption chiller for potable water and cooling generation with minimal cost thanks to the passive energy improvement method. In addition, proton exchange membrane electrolyzers are added for green hydrogen production from the surplus power. An in-depth thermodynamic, exergo-economic, and environmental assessment is conducted to evaluate the proposed renewable combination from all aspects using an engineering equation solver. Then, a multi-objective optimization method is implemented to find the most favorable operating condition in the MATLAB program. According to the results, chemical reactions, friction, and large temperature variations between the steam entering and leaving the gasifier unit are the main drivers of the energy system's exergy destruction. This is especially true in the gasifier unit. The gas turbine inlet temperature is vital for improving power generation and minimizing costs, according to the scatter distribution analysis of key design parameters. The results further show that energy and exergy efficiencies at the design condition are 39.5% and 28.1%. According to the results, the optimization improves the exergy efficiency and power production by 2.5% and 9000 kW, respectively. Finally, the optimum total cost and exergy destruction rates are 0.64 $/s and 85,496 kW, respectively.