Thermal Energy Storage in Solar Power Plants: A Review of the Materials, Associated Limitations, and Proposed Solutions

Abstract

Solar energy is the most viable and abundant renewable energy source. Its intermittent nature and mismatch between source availability and energy demand, however, are critical issues in its deployment and market penetrability. This problem can be addressed by storing surplus energy during peak sun hours to be used during nighttime for continuous electricity production in concentrated solar power (CSP) plants. This article reviews the thermal energy storage (TES) for CSPs and focuses on detailing the latest advancement in materials for TES systems and advanced thermal fluids for high energy conversion efficiency. Problems of TES systems, such as high temperature corrosion with their proposed solutions, as well as successful implementations are reported. The article also reviews the economic analysis on CSP plants with TES systems and life-cycle assessment to quantify the environmental impacts of different TES systems.

Molten salts: Potential candidates for thermal energy storage applications

“…Since the material is used at an industrial scale and the energy output at nuclear and solar power plants is enormous, the amount of the heat storage material used is also huge. Hence, the material must be inexpensive, abundant, and easily procurable 81 . Since the process of heat storage involves continuous heating and cooling of salts, the material must have decent cyclic stability, which is to say, it must have efficient freeze‐thaw cycles 82 .…”

“…Hence, the material must be inexpensive, abundant, and easily procurable. 81 Since the process of heat storage involves continuous heating and cooling of salts, the material must have decent cyclic stability, which is to say, it must have efficient freeze-thaw cycles. 82 The considered material must possess high thermophysical and thermochemical stability since the operating range of temperatures is very high.…”

Installation resilience in cold regions using energy storage systems

“…For smallerscale applications, the receiver is integrated with a parabolic trough, enclosed troughs, or Fresnel plants (Al-Juboori and Al-Shawwreh 2018). For larger-scale applications where the receiver is stand-alone, such as a solar tower, CSP plants have shown the most promise for grid-scale applications compared to other systems (Reilly and Kolb 2001;Alnaimat and Rashid 2019;Bielecki et al 2019). At the receiver, the solar energy is either used to create steam to drive a turbine for energy generation or stored as specific heat in a transfer medium to generate energy at a later time.…”

“…They are limited to regions that receive a large amount of direct solar energy. Molten salt is a mixture of 60 wt% sodium nitrate (NaNO3) and 40 wt% potassium nitrate (KNO3), making it susceptible to decomposition at high temperatures, limiting its heating capacity to 550°C and its ability to store thermal energy (Alnaimat and Rashid 2019). There have been successful efforts to increase its heat-storage capacity using additives, such as copper oxide (CuO) nanoparticles (Awad et al 2018).…”

Thermal Energy Storage for Grid Applications: Current Status and Emerging Trends

“…This paper is focused on the applications of thermal energy storage (TES) to enhance the operation of the electrical networks. From the literature, several reviews and contributions are available on the applications of TES to buildings, combined heat and power (CHP), district heating, and other thermal systems [13,14], and on the materials used in TES applications [15,16]. At the same time, several articles, reviews and reports address various types of electrical energy storage for grid applications [17][18][19][20].…”