In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with n

In this study different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (KNO3 selected as phase change material) wi

The technology for storing thermal energy as sensible heat, latent heat, or thermochemical energy has greatly evolved in recent years, and it is expected to grow up to about 10.1 billion US dollars by 2027. A thermal energy storage (TES) system can significantly improve industrial energy efficiency and eliminate the need for additional energy supply in commercial and residential applications. This study is a first-of-its-kind specific review of the current projected performance and costs of thermal energy storage. This paper presents an overview of the main typologies of sensible heat (SH-TES), latent heat (LH-TES), and thermochemical energy (TCS) as well as their application in European countries. With regard to future challenges, the installation of TES systems in buildings is being implemented at a rate of 5%; cogeneration application with TES is attested to 10.2%; TES installation in the industry sector accounts for 5% of the final energy consumption. From the market perspective, the share of TES is expected to be dominated by SH-TES technologies due to their residential and industrial applications. With regard to the cost, the SH-TES system is typically more affordable than the LH-TES system or the TCS system because it consists of a simple tank containing the medium and the charging/discharging equipment.

Thermal energy storage (TES) systems for concentrated solar power plants are essential for the convenience of renewable energy sources in terms of energy dispatchability, economical aspects and their larger use. TES systems based on the use of concrete have been demonstrated to possess good heat exchange characteristics, wide availability of the heat storage medium and low cost. Therefore, the purpose of this work was the development and characterization of a new concrete-based heat storage material containing a concrete mix capable of operating at medium–high temperatures with improved performance. In this work, a small amount of shape-stabilized phase change material (PCM) was included, thus developing a new material capable of storing energy both as sensible and latent heat. This material was therefore characterized thermally and mechanically and showed increased thermal properties such as stored energy density (up to +7%, with a temperature difference of 100 °C at an average operating temperature of 250 °C) when 5 wt% of PCM was added. By taking advantage of these characteristics, particularly the higher energy density, thermal energy storage systems that are more compact and economically feasible can be built to operate within a temperature range of approximately 150–350 °C with a reduction, compared to a concrete-only based thermal energy storage system, of approximately 7% for the required volume and cost.

This paper focuses on the thermo-economic analysis of a hybrid solar-biomass CHP combined cycle composed by a 1.3-MW externally fired gas-turbine (EFGT) and a bottoming organic Rankine cycle (ORC) plant. The primary thermal energy input is provided by a hybrid concentrating solar power (CSP) collector-array coupled to a biomass boiler. The CSP collector-array is based on parabolic-trough concentrators (PTCs) with molten salts as the heat transfer fluid (HTF) upstream of a fluidized-bed furnace for direct biomass combustion. Thermal-energy storage (TES) with two molten-salt tanks (one cold and one hot) is considered, as a means to reducing the variations in the plant's operating conditions and increasing the plant's capacity factor. On the basis of the results of the thermodynamic simulations, upfront and operational costs assessments, and considering an Italian energy policy scenario, the global energy conversion efficiency and investment profitability are estimated for 2 different sizes of CSP arrays and biomass furnaces. The results indicate the low economic profitability of CSP in comparison to only biomass CHP, because of the high investment costs, which are not compensated by higher electricity sales revenues