Energy Analysis of Molten-Salt Storage Integrated with Air-Based Brayton Cycle:Case Study of a Wind Farm in Denmark

Renewable energy sources like wind farms and solar farms have become very important in recent years. There are various methods for storing energy from these renewable sources. Molten Salt (MS) storage is a novel way to store excess electric power as high-Temperature thermal energy from which it can be converted to any form of energy. In the present study, the excess power of a wind farm is stored in the MS storage as heat. This heat is converted to power using an Air-Based Regenerative Brayton power cycle (A-BRB) when needed. Also, some of this heat could be utilized to heat water for the district heating (DH) application. A numerical model is presented for a power storage system using transient data from a real wind farm in Denmark. The energy analysis is applied to the proposed hybrid system. The results concluded that the energy efficiency of the proposed system is about 26.1%. The total amount of MS that could be stored in the storage is about 1267 kg. also, the proposed system could produce about 140 MW during the discharging time of 3.5 hours. In addition, the system could produce 143 kg/s of hot water during the discharging mode.</p

Optimizing Solar Energy Harvesting through Integrated Organic Rankine Cycle–Reverse Osmosis Systems: A Techno–Economic Analysis

When it comes to seawater desalination in the small- to medium-electricity ranges, the organic Rankine cycle (ORC) powered by solar energy stands out as the most energy-efficient technology currently available. Various solar techniques have been developed to capture and absorb solar energy. Among them, the parabolic trough collector (PTC) has gained recognition as a low-cost solar thermal collector with a long operating life. This study investigates the thermodynamic performance and economic parameters of a PTC-powered ORC using Dowtherm A and toluene as working fluids for the solar cycle and ORC cycle, respectively. Thermo-economic multi-objective optimization and decision-making techniques are applied to assess the system’s performance. Four key parameters are analyzed for their impact on exergy efficiency and total hourly cost. Using TOPSIS decision-making, the best solution from the Pareto frontier is identified, featuring an ORC exergy efficiency of 30.39% and a total hourly cost of 39.38 US$/h. The system parameters include a mass flow rate of fresh water at 137.7 m3/h, a total output net power of 577.9 kJ/kg, and a district heating supply of 1074 kJ/kg. The cost analysis reveals that the solar collector represents approximately 68$/h, followed by the turbine, thermoelectric generator, and reverse osmosis (RO) unit

A review study of various High-Temperature thermodynamic cycles for multigeneration applications

Multigeneration high-temperature systems are a type of energy system that use high-temperature heat sources to produce multiple forms of energy simultaneously. They offer several advantages over traditional energy systems, including higher energy efficiency, reduced greenhouse gas emissions, and lower operating costs. Power cycles are more efficient at higher temperatures. However, material and technical restrictions make operating beyond a certain temperature challenging. Multigeneration high-temperature systems are reviewed in this study. The focus is on cycles with temperatures above 550 °C from fossil fuels, solar heat, and molten salts as heat storage mediums. According to the literature, only gas turbine plants, supercritical and ultra-supercritical steam, and supercritical CO2 cycles are relevant for this temperature. Thus, these cycles are analyzed and reviewed in terms of their applications for multigeneration of power, heat, cooling, hydrogen, and freshwater. It is found that multigeneration systems based on the supercritical CO2 cycle are most efficient compared to others, while the ultra-supercritical steam cycle is still more efficient than the gas turbine cycle. Multigenerational supercritical steam cycles seldom worked, and this is a gap in the literature. A huge potential, much more than that already addressed by former studies, exists for multi-vector supply by supercritical CO2 cycles.</p

Real-Time Modeling and Optimization of Molten Salt Storage with Supercritical Steam Cycle for Sustainable Power Generation and Grid Support

This research article presents an innovative approach to enhance sustainable power generation and grid support by integrating real-time modeling and optimization with Molten Salt Energy Storage (MSES) and a Supercritical Steam Cycle (s-SC). As renewable energy usage grows, intermittent resource availability challenges grid stability and reliable power supply. To address this, we develop a system that merges real-time modeling and optimization for precise control of MSES and s-SC components. This integration ensures uninterrupted energy generation, storage, and distribution, optimizing renewable energy use during high-demand periods. Mathematical models and simulations assess the system's dynamic behavior, performance, and economic viability. Rigorous techno-economic analysis highlights cost-effectiveness and environmental benefits. Findings reveal exceptional energy efficiency and grid support, making it a promising solution for sustainable power generation and grid stability amid renewable energy growth. Real-time modeling and optimization emerge as crucial components in modern energy systems. The Combined Heat and Power (CHP) system achieves 56% energy efficiency with off-design impacts considered and 63.61% without. Also, the overall system exergy efficiency decreased from 73.36% at design to approximately 63.55% under off-design scenarios. Regarding the economic aspect, the levelized cost of storage (LCOS) for the CHP system is estimated at 114.4 €/MWh with off-design conditions and 106.8 €/MWh without