Using liquid metal to develop energy storage systems with 100 times better heat transfer

The economic manufacturing of metal, concrete, or glass requires greater than 20% of Germany’s whole power consumption. To date, 90% of the fuels used for these processes have been of fossil nature.

Researchers of Karlsruhe Institute of Expertise (KIT) are engaged on the one high-temperature warmth storage system based mostly on liquid-metal expertise of this sort with a purpose to improve the usage of renewable power sources. The extremely conductive liquid metals will be heated to greater than 700°C utilizing inexperienced electrical energy and might flexibly retailer industrial warmth.

From April 22 to 26, 2024, the researchers will current a mannequin of their power storage system on the KIT stand on the Vitality Options (Corridor 13, Stand C76) of the Hannover tradefair.

Worldwide, high-temperature warmth storage programs are being developed to provide resource-intensive manufacturing firms with warmth independently of fluctuating renewable power manufacturing. These storage programs convert electrical power into warmth, which is then saved.

The warmth is used if wanted, as an illustration when electrical energy is dear and production processes can’t be stopped. The upper the temperature saved, the higher. This reduces the quantity of further power that might be wanted to achieve the specified manufacturing temperature.

Pilot crops are utilizing liquid salts to retailer temperatures of round 550°C. Even greater temperatures have been achieved with gases thus far. When electrically heated to about 700°C, they switch their warmth to storage supplies resembling metal, volcanic rock or slag. “Nevertheless, the heat transfer from the new gasoline to the storage materials is way from being environment friendly,” says Dr. Klarissa Niedermeier from KIT’s Institute for Thermal Vitality Expertise and Security.

Glorious warmth switch by means of liquid metals

Collectively along with her workforce, she is engaged on a novel resolution for the high-temperature vary: A warmth storage system based mostly on lead-bismuth. “The thermal conductivity of this mix of liquid metals is 100 times higher than that of other materials used in storage systems,” Niedermeier says.

The high-temperature warmth storage system is being examined in a loop. In a metal tank, the heated lead-bismuth seeps by means of ceramic beads of about 2 mm in dimension, releases its warmth to them. When the warmth is required once more, the “cold” liquid metallic is returned by means of the beads and heats up once more.

Simulations at KIT’s liquid-metal laboratory KALLA have confirmed that the usage of liquid metallic will increase the effectivity of warmth storage, particularly when a really compact package deal is used.

Environment friendly storage of extra inexperienced energy

“When the liquid metal is heated with power from renewable energy sources, companies have an efficient solution to mitigate fluctuations of power supply and to enable simple, inexpensive, and rapid energy storage at temperatures that are as close as possible to those used in industrial processes,” Niedermeier factors out.

The method has an amazing potential to defossilize trade. Industrial processes in Germany eat 400 terawatt hours of warmth per yr, and 90% of the fuels utilized in these processes are fossil.

Thus far, liquid metals have hardly been utilized in warmth storage systems. In accordance with Niedermeier, that is primarily on account of logistical causes. There are only some closed-loop programs on the earth, wherein such a warmth storage system will be examined. KALLA has a big lead-bismuth cycle, which is used for brand spanking new initiatives within the discipline of renewable energy sourcesamongst others.

At this yr’s Hannover Messe, the workforce will current a mannequin of the warmth storage system, its dimension being about half that of the true system at KIT. The system at KIT is designed to retailer 100 kilowatt-hours of warmth and has been examined on the laboratory scale at temperatures of as much as 400°C thus far.

“This is the world’s liquid-metal heat storage system of this kind with such a capacity. We want to show that the principle works and that it has great potential,” says Klarissa Niedermeier.