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The integration of high temperature thermal energy storages into existing conventional power plants can help to reduce the CO2 emissions of those plants and lead to lower capital expenditures for building energy storage systems, due to the use of synergy effects [1]. One possibility to implement that, is a molten salt storage system with a powerful power-to-heat unit. This paper presents two possible control concepts for the startup of the charging system of such a facility. The procedures are implemented in a detailed dynamic process model. The performance and safety regarding the film temperatures at heat transmitting surfaces are investigated in the process simulations. To improve the accuracy in predicting the film temperatures, CFD simulations of the electrical heater are carried out and the results are merged with the dynamic model. The results show that both investigated control concepts are safe regarding the temperature limits. The gradient controlled startup performed better than the temperature-controlled startup. Nevertheless, there are several uncertainties that need to be investigated further. [ABSTRACT FROM AUTHOR]

In implementing thermochemical energy storage, the selection of storage medium and the design of the associated discharge process are crucial; in this work the CaO/Ca(OH)2 system was chosen as it is well understood in the literature and is a cheap and accessible material though the associated storage/discharge process has not been studied in depth, particularly in the context of fluidized bed reactor configurations which offer superior technical performance but remain challenging to operate and study. This work sought to design a combined energy storage and discharge fluidized- bed based process flowsheet involving the CaO/Ca(OH)2 system coupled with a CSP receiver setup and discharge power cycle (CSP-TCES). AspenPlus V9 was used to design fluidized bed reactors for each process, and then simulate and optimize fluidized bed-based flowsheets with a sensitivity analysis, and results were compared with analytical models from literature. Historical solar irradiance data for Seville, Spain, was used to dynamically simulate hourly solar loads coupled with multiple discharging schedules considered for a rough sensitivity analysis to assess the average loading and discharge trends of the designed plant. A subsequent techno-economic analysis yielded estimated levelised costs of electricity of 0.118-0.163 $/kWh and levelised costs of storage of 0.057-0.078 $/kWh showing the CSP-TCES system as very competitive with alternative more-developed storage technologies and associated discharge technologies. [ABSTRACT FROM AUTHOR]

The objective of this paper is the evaluation of trends when a power-to-heat system with electrical heaters is integrated to a molten salt solar tower to additionally charge the thermal energy storage system and to expand the capacity of the CSP plant. Therefore a techno-economic analysis was carried out considering several economical and technical boundary conditions. The results show a significant impact on the availability of excess electricity and its cost. Depending on system layout and the cost of the used electricity the overall LCOE of such plants can be reduced by up to 25%. Therefore such power-to-heat systems can offer an economic and strategic benefit to solar thermal power plants. [ABSTRACT FROM AUTHOR]

In order to solve the development of renewable energy and improve the output power quality of renewable energy, a non-supplemental combustion compressed air energy storage system based on STAR-90 simulation was designed. The proportion of large power grids that accept renewable energy was analysed and studied in detail. During the use of the corresponding C++ algorithm, the corresponding model was constructed. Simulation debugging was implemented from the application of the STAR-90 simulation platform, and the parameters of the system were analysed. The results showed that in the context of large-scale development of photovoltaic and wind energy and environmental protection, the noncompensated compressed air energy storage system was the best choice to solve the current serious problem of abandoned light and abandoned wind. Therefore, the system has important significance for the large-scale development of renewable energy. [ABSTRACT FROM AUTHOR]

The increase of electric power demand and the wish to protect the environment are leading to a change in the energy sources. Conventional energy plants are losing strength against the renewable energy plants and, in particular, solar energy plants have a huge potential to provide clean energy supply for the increasing world's energy demand. Among the existing solar technologies, Concentrating Solar Power (CSP) is one of the most promising technologies. One of the major advantages of CSP plants is the technically feasible and cost-effective integration of Thermal Energy Storage (TES) systems. To increase the plant dispatchability, it is possible to create different operational strategies defining how such TES system is used. In this work, different strategies with different overall goals have been simulated over a complete year and the results are presented and compared here to demonstrate the capabilities of the operational strategies towards an increased dispatchability and plant economic effectiveness. The analysis shows that different strategies may lead to significant differences in the plant annual production, expected economic incomes, number of power block stops, mean efficiency, etc. Specifically, it has been found that the economic incomes of a plant can be increased (+1.3%) even with a decreased total energy production (-1.5%) if the production is scheduled to follow a demand/price curve. Also, dramatic reduction in the number of turbine stops (-67%) can be achieved if the plant is operated towards this objective. The strategies presented in this study have not been optimized towards any specific objective, but only created to show the potential of well designed operational strategies in CSP plants. Therefore, many other strategies as well as optimized versions of the strategies explained below are possible and will be analyzed in future works. [ABSTRACT FROM AUTHOR]

Surface structure and its chemical composition play an important role in energy and momentum exchange in non-equilibrium gas-surface system. Any variation in micro parameters of interface both of chemical and structural character can lead to dramatically change in macroscopic heat flow between the gas and the surface as well as in gas dynamic friction of the solid body moving in a gas atmosphere. The main goal of this research is to study the surface structure influence on energy and momentum exchange in gas-surface systems and to simulate the process of gas molecule interaction with the solids. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The Atlas facility built by Los Alamos is the world’s first and only laboratory pulsed power system designed specifically to provide capability for shock-wave physics, materials properties, instability, and hydrodynamics experiments in converging geometry. Constructed in 2000 and commissioned in August 2001, Atlas completed its first year of physics experiments in October 2002, using ultra high precision magnetically imploded, cylindrical liners to reliably and reproducibly convert electrical energy to hydrodynamic energy in targets whose volume is many cubic centimeters. Multi-view (transverse and axial) radiography, laser-illuminated shadowgraphy, and VISAR measurements of liner and target surface motion, in addition to electrical diagnostics, provide a detailed description of the behavior of the experimental package. In the first year material damage and failure experiments, dynamic friction experiments, and a family of converging shock experiments were conducted in addition to a detailed series of liner implosion characterization experiments. These experiments will continue and additional series to evaluate material strength at very high rates of strain, ejecta formation from surfaces, and instability growth at interfaces will be added in the future. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]