Techno-Economic Forecasts of Lithium Nitrates for Thermal Storage Systems

Abstract

Thermal energy storage systems (TES) are a key component of concentrated solar power (CSP) plants that generally use a NaNO 3 /KNO 3 mixture also known as solar salt as a thermal storage material. Improvements in TES materials are important to lower CSP costs, increase energy efficiency and competitiveness with other technologies. A novel alternative examined in this paper is the use of salt mixtures with lithium nitrate that help to reduce the salt's melting point and improve thermal capacity. This in turn allows the volume of materials required to be reduced. Based on data for commercial plants and the expected evolution of the lithium market, the technical and economic prospects for this alternative are evaluated considering recent developments of Lithium Nitrates and the uncertain future prices of lithium. Through a levelized cost of energy (LCOE) analysis it is concluded that some of the mixtures could allow a reduction in the costs of CSP plants, improving their competitiveness.

Magnesium based materials for hydrogen based energy storage: Past, present and future

“…Currently molten salts are limited to a maximum operating temperature of 565 °C, at which point they decompose [350]. In addition, this technology uses sensible heat storage, which is 153 kJ kg −1 K -1 [353]. Current targets for implementing metal hydrides as thermal batteries would require these thermo-chemical storage materials to operate at temperatures of > 600 °C.…”

Effects of molten-salt LiNO3 on high-temperature corrosion behaviour of absorption tubes of a concentrating solar power system

“…Based on their costs, nitrate salts can be arranged in descending order as follows: Li > K>Na > Ca. [2] However, the use of salt mixtures with lithium nitrate results in the high thermal stability, increased energy efficiency, low salt melting point, high thermal capacity, and an increase in the working temperature range of salt, which in turn allow the required volume of the salts for a thermal energy storage system to be reduced [17,18].…”