scholarly journals Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

2015 ◽  
Vol 6 ◽  
pp. 1487-1497 ◽  
Author(s):  
Nicole Pfleger ◽  
Thomas Bauer ◽  
Claudia Martin ◽  
Markus Eck ◽  
Antje Wörner

Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

Energy ◽  
2012 ◽  
Vol 48 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Marko Ban ◽  
Goran Krajačić ◽  
Marino Grozdek ◽  
Tonko Ćurko ◽  
Neven Duić

Author(s):  
Reza Baghaei Lakeh ◽  
Ian C. Villazana ◽  
Sammy Houssainy ◽  
Kevin R. Anderson ◽  
H. Pirouz Kavehpour

The share of renewable energy sources in the power grid is showing an increasing trend world-wide. Most of the renewable energy sources are intermittent and have generation peaks that do not correlate with peak demand. The stability of the power grid is highly dependent on the balance between power generation and demand. Compressed Air Energy Storage (CAES) systems have been utilized to receive and store the electrical energy from the grid during off-peak hours and play the role of an auxiliary power plant during peak hours. Using Thermal Energy Storage (TES) systems with CAES technology is shown to increase the efficiency and reduce the cost of generated power. In this study, a modular solid-based TES system is designed to store thermal energy converted from grid power. The TES system stores the energy in the form of internal energy of the storage medium up to 900 K. A three-dimensional computational study using commercial software (ANSYS Fluent) was completed to test the performance of the modular design of the TES. It was shown that solid-state TES, using conventional concrete and an array of circular fins with embedded heaters, can be used for storing heat for a high temperature hybrid CAES (HTH-CAES) system.


2013 ◽  
Vol 17 (2) ◽  
pp. 431-442 ◽  
Author(s):  
Ledesma Tores ◽  
Piotr Lapka ◽  
Roman Domański ◽  
Francisco Casares

Nowadays, due to increase in energy consumption, a great deal of fossil fuels is being used. This latter is a consequence of the present environmental problems, such as global warming, acid rain, etc. In order to decrease these problems, the use of renewable energy sources is being promoted. But the renewable energy sources, particularly solar energy, present the drawback that there is a mismatch between the energy demand and supply. To cover this mismatch, the use of phase change thermal energy storage systems is required. In this work, the behavior of a packed bed latent heat thermal energy storage system cooperating with solar collector located in south Spain was analyzed by using a numerical method which based on Finite Volume discretization and Enthalpy Method. The model was validated by comparing obtained results with experimental data reported in the literature. The packed bed was composed of spherical capsules filled with phase change materials usable for a solar water heating system. The system was designed according to the conditions in the south Spain and by using commercial components available on the market. A series of numerical simulations were conducted applying meteorological data for several months in south Spain, particularly in M?laga.


Author(s):  
Romano Acri ◽  
Fulvio Bassetti ◽  
Maria Carmen Falvo ◽  
Letizia Magaldi ◽  
Matteo Manganelli ◽  
...  

The decarbonization of the electrical energy sector is in progress for contrasting the climate changes, with a relevant increase of the Renewable Energy Sources (RES) power plants, mostly in Dispersed Generation (DG). The adequacy and the security of power systems, with a huge penetration of RES in DG is possible with a suitable integration of energy storage. In fact, energy storages are able to provide many different services for long-term adequacy and real time security. In this framework the present paper deals with a Thermal Energy Storage (TES) proposed for power system services. The technology presented is made up of modules containing a bed of fluidizable solid particles, which can store thermal energy from waste heat, process heat and/or from electricity. Stored thermal energy can be released, e.g. as superheated steam, for thermal uses or converted into electricity, by means of steam turbines. Some possible applications are then reported explaining advantages and limits.


2019 ◽  
Vol 9 (5) ◽  
pp. 814 ◽  
Author(s):  
Zhu Jiang ◽  
Feng Jiang ◽  
Chuan Li ◽  
Guanghui Leng ◽  
Xuemin Zhao ◽  
...  

Thermal energy storage (TES) is a highly effective approach for mitigating the intermittency and fluctuation of renewable energy sources and reducing industrial waste heat. We report here recent research on the use of composite phase change materials (PCM) for applications over 700 °C. For such a category of material, chemical incompatibility and low thermal conductivity are often among the main challenges. Our aims are to address these challenges through the formulation of form-stable composite PCMs and to understand their thermophysical properties. The eutectic K2CO3-Na2CO3 salt was used as a PCM with MgO as a form stabilizer. We found that such a formulation could maintain shape stability with up to 60 wt.% PCM. With a melting point of ~710.1 °C and an energy density as high as 431.2 J/g over a temperature range between 550 °C and 750 °C, the composite PCM was shown to be thermally stable up to 885 °C. An addition of 10 wt.% SiC enhanced the overall thermal conductivity from 1.94 W·m−1 K−1 to 2.28 W·m−1 K−1, giving an enhancement of 17.53%. Analyses of thermal cycling data also showed a high extent of chemical compatibility among the ingredients of the composite PCM.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2429 ◽  
Author(s):  
Lorenzo Bartolucci ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
Marina Santarelli

Energy Management System (EMS) optimal strategies have shown great potential to match the fluctuating energy production from renewables with an electric demand profile, which opens the way to a deeper penetration of renewable energy sources (RES) into the electric system. At a single building level, however, handling of different energy sources to fulfill both thermal and electric requirements is still a challenging task. The present work describes the potential of an EMS based on Model Predictive Control (MPC) strategies to both maximize the RES exploitation and serve as an ancillary service for the grid when a Heat Pump (HP) coupled with a Thermal Energy Storage (TES) is used in a residential Hybrid Renewable Energy System (HRES). Cost savings up to 30% as well as a reduction of the purchased energy unbalance with the grid (about 15%–20% depending on the season) have been achieved. Moreover, the thermal energy storage leads to a more efficient and reliable use of the Heat Pump by generally decreasing the load factor smoothing the power output. The proposed control strategy allows to have a more stable room temperature, with evident benefits also in terms of thermal comfort.


2021 ◽  
Author(s):  
Karin Astrid Senta Edel ◽  
František Hrdlička ◽  
Václav Novotný

As part of the change towards a higher deployment of renewable energy sources, which naturally deliver energy intermittently, the need for energy storage systems is increasing. For compensation of disturbance in power production due to inter-day to seasonal weather changes, long-term energy storage is required. In the spectrum of storage systems, one out of a few geographically independent possibilities is the storage of electricity in heat, so-called Carnot-Batteries. This paper presents a Pumped Thermal Energy Storage (PTES) system based on a recuperated supercritical CO2 Brayton cycle. The modelled system provides a round-trip efficiency of 38.9%.


Sign in / Sign up

Export Citation Format

Share Document