Storage Techniques for Solar Thermal Applications

ICRRD HIGH INDEX RESEARCH JOURNAL., 2020

The usage of renewable and clean solar energy is expanding at a rapid pace. Applications of thermal energy storage (TES) facility within the solar power field enables dispatch ability within the generation of electricity and residential space heating requirements. It helps mitigate the intermittence issue with an energy source like solar power. TES also helps in smoothing out fluctuations in energy demand during different time periods of the day. During this paper, a summary of varied solar thermal energy storage materials and thermal energy storage systems that are currently in use is presented. The properties of solar thermal energy storage materials are discussed and analyzed. The dynamic performances of solar thermal energy storage systems in recent investigations are presented and summarized. Storage methods can be classified into categories according to capacity and discharge time. New developments in solar energy storage require advances in chemical engineering and materials ...

Comptes Rendus Physique

Stockage de chaleur sensible Stockage de chaleur latente Stockage de chaleur enlever l'adjectif latente thermochimique Solar thermal energy storage is used in many applications, from building to concentrating solar power plants and industry. The temperature levels encountered range from ambient temperature to more than 1000 • C, and operating times range from a few hours to several months. This paper reviews different types of solar thermal energy storage (sensible heat, latent heat, and thermochemical storage) for low-(40-120 • C) and medium-to-hightemperature (120-1000 • C) applications.

The thermal performance of the PV/T (photovoltaic thermal) system and conventional collector is affected by water storage capacity. There are limited studies which show the effects of the storage capacity on the performance of different solar systems. This paper measures and analyzes the performance of a photovoltaic thermal system, conventional collector, and PV (photovoltaic) plate at different water storage capacities (25, 50, 75, 100, and 125 kg/m 2 ). The cost payback period of the solar systems was calculated with the electricity price of South Korea (0.049 US$/kWh) and for the country with the highest electricity price of 0.364 US$/kWh (Australia). The thermal efficiency of the PV/T system and conventional collector increased sharply with increasing storage capacity. The cost payback period of the PV/T system and conventional collector reduced considerably with increasing storage capacity. Similarly, the cost payback period of PV/T system and PV plate reduced remarkably when electricity price increased from 0.049 to 0.364 US$/kWh. The selection of the proper storage capacity could play a vital role for the performance enhancement and cost reduction in the PV/T system and the conventional collector.

Journal of Energy Technologies and Policy, 2019

There is a growing concern in the operating of solar power as a stand-alone and its connection to the grid. This is because; its power quality and sustainability are being affected by intermittency and variability. As the time of the day and the solar intensity changes, the quality of power generation is affected. This has made the use of energy storage inevitable for a quality power generation. This paper considers some existing technologies of energy storage that is applicable in mitigating the challenge facing the deployment of solar power systems. The variability and effectiveness of these storage techniques were considered in terms of technology, efficiency, environmental impact, and response. In conclusion, it was resolved that a self-sufficient solar power system requires appropriate storage techniques to complement its operation. Therefore, understanding the different options of storage is required for a careful selection of the technology which can support the required level of efficiency and effectiveness in electrical energy generation.

2020

Energy demand depend strongly on growth of world population, householders and urbanization. The energy consumption forecasting allows to give a guide for the future development in technologies. The need in energy saving as an energy source and the thermal energy storage can play a strategic role in energy recovering. After a general description of the main concept of thermal energy storage are given the classification of the different storage systems involved in several applications. It is underlined that one of the main applications is related to the solar energy conversion systems and their development is linked to the economic policy choices on energy.

h i g h l i g h t s " The latest developments in solar thermal applications are reviewed. " Various types of solar collectors are summarised. " Thermal energy storage approaches and systems are discussed. " The current status of existing solar power stations is reviewed. a b s t r a c t Thermal applications are drawing increasing attention in the solar energy research field, due to their high performance in energy storage density and energy conversion efficiency. In these applications, solar collectors and thermal energy storage systems are the two core components. This paper focuses on the latest developments and advances in solar thermal applications, providing a review of solar collectors and thermal energy storage systems. Various types of solar collectors are reviewed and discussed, including both non-concentrating collectors (low temperature applications) and concentrating collectors (high temperature applications). These are studied in terms of optical optimisation, heat loss reduction, heat recuperation enhancement and different sun-tracking mechanisms. Various types of thermal energy storage systems are also reviewed and discussed, including sensible heat storage, latent heat storage, chemical storage and cascaded storage. They are studied in terms of design criteria, material selection and different heat transfer enhancement technologies. Last but not least, existing and future solar power stations are overviewed.

2019

Milk is a highly perishable commodity and needs quick processing to prevent growth of microorganisms. Milk processing mainly contains heating and cooling operations and for most of the heating operations, steam is used as a heat transfer fluid. But the increasing energy demand leads to search for alternative renewable energy resources. Sun energy is highly efficient, free to use and does not harm the environment. A comparative study was done to select best heat transfer material for heating operations in milk processing. During the study, different energy storage materials viz. thermal fluids and phase changing material (PCM) in the form of salts were investigated to check their thermal profile, engineering characteristics viz. thermal expansion, melting point, smoke point etc. were evaluated. Sensible heat energy storage of thermal fluids namely; paraffin oil (light), silicon oil and phase changing salts namely; acetamide, magnesium chloride hexahydrate were analyzed for their heat absorption and thermo-physical properties. Among these four materials, paraffin oil was found as highest thermal energy absorbing material. The phase changing salts has more heat storage density as they absorb the heat in the form of latent heat. This leads to the storage of thermal energy for a longer period, once the salts are charged by heating but maximum heat energy was absorbed by paraffin oil (276˚C276˚276˚C) surging ahead of silicon oil (260˚C260˚260˚C). Peak temperature achieved by these oils is more than sufficient to cover the entire range of heating operations required in dairy process industries. Introduction With increasing population, there is a huge increase in energy demand which is fulfilled with both renewable and non-renewable energy sources. In India, only 28% of energy demand is met with renewable energy resources and rest is met from non-renewable sector which automatically results in huge emission of carbondioxide. Shortage of fossil fuels, associated ill effects of use of fossil fuels on environment and ever increasing demand for energy compels us to shift towards renewable energy resources like solar energy, wind energy, geothermal energy, tidal energy, biomass etc. as these energy resources are free, anti-polluting and anti-toxic to the environment. Among these energy resources, solar energy has a great scope in a country like India where sun shines in abundance. India gets around 5-7 KW/m 2 of sunshine for about 300-320 days per year (Desai et al. 2013, Sharma et al. 2012) [5, 12]. In addition, energy storage can help to save the premium fuels and also reduces the wastage of conventional energy.

2015

Solar energy has a large potential, therefore it is a dominating source over other resources ,However its intermittent nature demands an storages system along with collector in order to make it more reliable. Solar air heaters utilize the rock bed as their storage system. This stored energy in rock bed can be used for providing the continuous supply of thermal energy in the absence of sun and it can also be used in addition to the current supply. In order to design a packed bed energy storage system, the matter of concern is to maximize the heat transfer with minimum pressure drop or pumping power. The paper is aimed at investigating the behavior of rock bed solar energy storage system, which is used to deliver the heat energy to a room. i,e the load (to heat a room ) is supposed to be 250 KW and requirement duration is 24 hours. The overall performance of such systems is influenced significantly by the temperature distribution in storage unit which is affected by the system parame...

In this paper, a review has been conducted on various types of methods which are available for utilizing solar energy for refrigeration purposes. Solar refrigeration methods such as Solar Electric Method, Solar Mechanical Method and Solar Thermal Methods have been discussed. In solar thermal methods, various methods like Desiccant Refrigeration, Absorption Refrigeration and Adsorption Refrigeration has been discussed. All the methods have been assesed economically and environmentally and their operating characteristics have been compared to establish the best possible method for solar refrigeration. Also, the various available technologies for Cooling Thermal Energy Storage (CTES) have been discussed in this paper. Methods like Chilled Water Storage (CWS) and Ice Thermal Storage (ITS) have been compared and their advantages and disadvantages have been discussed. The results of the review reveal Solar Electric Method as the most promising method for solar refrigeration over the other methods. As far as CTES systems are concerned, ITS has advantage over other methods based on storage volume capability, but it has a comparatively lower COP than other available techniques.

Thermal Energy Battery with Nano-enhanced PCM, 2018

Solar intermittency is a major problem, and there is a need and great interest in developing a means of storing solar energy for later use when solar radiation is not available. Thermal energy storage (TES) is a technology that is used to balance the mismatch in demand and supply for heating and/or cooling. Solar thermal energy storage is used in many applications: buildings, concentrating solar power plants and industrial processes. Solar thermal water heaters capable of heating water during the day and storing the heated water for evening use are common. TES improves system performance by smoothing supply and demand and temperature fluctuations. Thermal energy storage has become a fast-growing business. According to a research report, the global thermal energy storage market is expected to reach USD 12.50 billion by 2025. The chapter describes different types of thermal energy storage systems. Brief history, current state of research and the future of thermal storage are presented. Types of thermal storages, classifications, advantages and disadvantages are discussed; important thermal and physical properties are tabulated. Advances in enhancement of thermal properties of materials are briefly discussed. Challenges, opportunities, market outlook, government incentives and polices that support deployment of energy storage systems are outlined.