The photo is sourced from mgathermal.com
The main element of the storage systems will be the so-called Miscibility Gap Alloy (MGA), which, when heated, is able to accumulate thermal energy while remaining outwardly solid. This effect will be achieved by using materials with different melting points: the lower melting point material will be present within the higher melting point material in the form of discrete particles. Energy accumulation will occur due to the heating of the alloy particles (up to 400–700 degrees Celsius), which will be embedded in the blocks based on graphite, whose melting point is 3,890 degrees Celsius.
MGA Blocks will have the advantage of storing energy for long-term periods lasting from a couple of hours to several days. Heat exchangers will use a carrier gas to absorb energy from MGA Blocks. This will also make it possible to use the heated gas in industrial installations and in steam turbines that generate electricity.
The commercialization of MGA Blocks will mark another innovation in the field of thermal energy storage. Earlier, Finland’s Polar Night Energy launched the world’s first sand-based thermal energy storage, a steel silo with a capacity of 100 tons. The reservoir, which is filled with dry and clean sand, contains heat transfer pipes whose structure resembles a spring. The energy accumulation chain consists of three stages. First, excess electricity is fed to a resistance heater which heats the air to 500–600 degrees Celsius. The air is then sent via pipes to the silo where sand is heated to the same temperature. Finally, at the energy extraction stage, the pipes are blown with cold air, as a result of which the exhaust pipe starts to transfer heat which can be used for heating purposes.
