In pursuit of sustainable development and mitigation of the intermittency challenge associated with solar energy, this study proposes a hybrid solar system integrating waste heat incineration alongside solar power generation and distinct heat provision. Leveraging the superior energy efficiency of the organic Rankine cycle (ORC) in medium- and low-temperature scenarios, a parabolic trough collector (PTC) is selected for its cost-effectiveness and long-term operational reliability. Dowtherm A and toluene are identified as the optimal working fluids for the PTC and ORC, respectively. To optimize this complex system, a combination of artificial neural networks (ANNs) and multi-objective optimization via non-dominated sorting genetic algorithm II (NSGA-II) is employed, streamlining the optimization process. Thermal dynamic simulations are executed using Engineering Equation Solver (EES, V11) to validate the proposed system’s performance. TOPSIS is employed to identify the optimal solution from the Pareto frontier. The results indicate that the hourly cost of the system stands at USD 43.08, with an exergy efficiency of 22.98%. The economic analysis reveals that the solar collector constitutes the most significant portion of the total initial cost, representing 53.2%, followed by the turbine, thermoelectric generator (TEG), and waste heat incineration, in descending order of costliness.

Biomass, including municipal solid waste, and solar energy are two of the inevitable sources for future decarbonized energy systems. Fresnel lens thermal collectors using cheap micro-structured foils is an interesting emerging medium-temperature solar thermal design that might be of high practical value, provided that its fluctuating output is managed. This study proposes a hybrid solar-waste solution using this type of collector for multi-generation via an Organic Rankine Cycle. The cycle is specially designed for supplying low-grade heat, power, and industrial heat (which is a very critical sector to be decarbonized) taking advantage of the generated stable solar-waste medium-temperature heat at zero emission level. To achieve this optimal design, the article conducts a thorough energy-exergy-economic-environment (4E) analysis of the system and employs the non-dominated sorting genetic algorithm (NSGA II) for the optimizations. A benchmarking analysis is also conducted to show the importance of industrial heat supply in this cycle. The results show that this hybridization, owing to the cheap and flexible heat delivery of the waste incinerator as well as the low cost of the solar collectors, is very effective for efficient and cheap multi-generation. Especially for industrial heat supply, the competitive levelized cost of energy (LCOE) of 23.96 €/MWh is obtained, which is way lower than today's achievable costs in the industry.

The poor operational stability of electrolytes is a persistent impediment in building redox flow battery technology; choosing suitable stability additives is usually the research direction to solve this problem. The effects of five phosphate containing additives (including 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), hexamethylene diamine tetramethylene phosphonic acid (HDTMPA), amino trimethylene phosphonic acid (ATMPA), sodium ethylenediamine tetramethylene phosphonate (EDTMPS), and diethyl triamine pentamethylene phosphonic acid (DTPMP)) on the thermal stability and electrochemical performance of the positive electrolyte of vanadium redox flow battery were investigated. With 0.5 wt% addition, most of the selected additives were able to improve the thermal stability of the electrolyte. HEDP and HDTMPA extended the stability time of the pentavalent vanadium electrolyte at 50 °C from 5 days (blank sample) to 30 days and 15 days, respectively. The electrochemical performance of the electrolyte was further investigated by cyclic voltammetry, steady state polarization, and electrochemical impedance spectroscopy tests. It was found that most of the additives enhanced the electrochemical activity of the positive electrolyte, and the diffusion coefficients, exchange current densities, and reaction rate constants of V(IV) species became larger with the addition of these additives. It is verified that the thermal stability and electrochemical stability of the electrolyte are significantly improved by the combination of ATMPA + HEDP or ATMPA + HDTMPA. This study provides a new approach to improve the stability of the positive electrolyte for vanadium redox flow battery.