L R AS Published on Monday 15 May 2023 - n° 445 - Categories:other methods
Testing molten salt to conserve energy
A full-scale test will be conducted in Denmark with a 1.6 MWh storage at 700°C. It uses the technology of energy storage in concentrated solar power at a temperature of 700°C.
The energy is stored for up to two weeks.
The salt will be heated by electric heaters, first to 350°C, then to 700°C, and finally stored in a hot tank
At the time of discharge, the salt in the hot tank is circulated to the steam generator, where the heat is transferred to water, generating high temperature steam. The steam can be used directly in an industrial process or used to power a turbine to generate electricity and district heating.
The efficiency of the storage system varies according to its use. For process heat, the project envisages an efficiency of around 90%. For cogeneration, the efficiency is between 80% and 90%. For electricity generation alone, an efficiency of around 40% is expected.
As sodium hydroxide can be produced at low cost from seawater as a by-product of chlorine production, this would cost six times less than the standard salts used for storage.
https://www.pv-magazine.com/2023/05/10/storing-renewables-with-molten-hydroxide-salts/
PV Magazine of 10 May 2023
Editor's note: It is curious that we are returning to the appeal of molten salt, which has been used many times in photovoltaic concentrators. It retains heat for a longer period of time than lithium-ion energy retention.
