Renewable energy resources: Heading in the direction of large-scale thermal storage systems

• High-temperature technologies make it possible for electrothermal storage space systems for large amounts of energy from renewable sources.

Karlsruhe Institute of Technology (KIT), the German Aerospace Center (DLR), and the industry partner KSB have actually currently launched the LIMELISA project to establish the essential basis. Research is moneyed with EUR 3.8 million by the Federal Ministry for Economic Affairs and Energy.

Each year, wind parks and solar facilities in Germany create thousands of gigawatt hrs of power that can not be used directly and consequently remain unused. At various other times, doing not have abilities are compensated by energy from fossil sources. Large-scale electrothermal storage space systems may address this trouble and in addition enhance grid security. The idea is to transform power into heat, to buffer this heat in comparably inexpensive storage systems, and to reconvert it right into power, if needed.

" When utilizing media, such as salt thaws and liquid metals, for storage and heat transfer, very high temperatures can be gotten to," says Professor Thomas Wetzel, that carries out research at KIT's Institute for Thermal Energy Technology and Safety And Security (ITES) and Institute of Thermal Refine Design. "This opens new applications for thermal storage systems in industry and produces ecologically and financially sustainable choices for the climate-friendly change of energy supply."

Thermal storage space systems are currently made use of on the industrial scale. Focusing solarthermal centers store heat in salt thaws. Heavy steam nuclear power plant transform the heat right into power. Under the LIMELISA (represent Liquid Metal and Liquid Salt Heat Storage space System) project, researchers of KIT support the growth of next-generation thermal storage systems, which are particularly developed for the power-heat-power procedure.

Work focuses on liquid metal technologies, whereas DLR concentrates on salt thaws. Research is collaborated and enhanced by KSB, a globally running manufacturer of pumps and installations that started to work with liquid-metal circuits in the 1960s.

Materials and Components for Highly Efficient Energy Storage Equipments

Traditional electrothermal storage systems are operated the basis of e.g. nitrate salt. Because of the materials and elements (pumps, shutoffs) used, nonetheless, they have actually only been run at temperatures of as much as 560C until now. "For reconversion of heat into power by traditional steam nuclear power plant, much greater temperatures are called for," claims project head Dr. Klarissa Niedermeier, ITES.

" At KIT, we will check vital parts in a lead cycle of as much as 700C." As a result of route contact with the fluid metal, unique products are called for, which are likewise created and tested at KIT. At the Institute for Pulsed Power and Microwave Technology, Dr. Alfons Weisenburger research studies these special steel blends. "Standard rust security methods are no more sufficient at such temperature levels," he describes. "To name a few, we make use of aluminum oxide as a type of guard to secure pumps and fittings."

Numerous Applications in Industry

Thermal storage systems can be used in several areas, consisting of field coupling. Besides the power-heat-power process examined by LIMELISA, the technologies established can additionally be utilized to supply heat connect with renewable power. Such technologies can efficiently supply the high-temperature process heat called for by chemical or construction sectors or for metal handling.

" Presently, this high-temperature heat demand is mainly satisfied by fossil energy resources," states Dr. Walter Tromm, Head of ITES. "High-temperature thermal storage space systems would certainly be an elegant alternative to make use of regenerative energy for vital industrial processes and to address the problem of unstable availability of regenerative energy sources."