MAN Energy Solutions has signed a cooperation agreement with ABB for the development, production and commercialization of a three-way energy-storage system. The new Electro-Thermal Energy Storage system (ETES) stores large-scale electricity, heat and cold for distribution to consumers.
ETES uses surplus renewable-electricity to generate heat and cold for storage in insulated reservoirs during a so-called ‘charging cycle’. The heat and cold can be converted back into electrical energy on demand. Moreover, it is possible to distribute the stored cold and heat to different types of consumers. For instance, heat can be transferred to district heating, the food-processing industry, laundry facilities, etc., whereas applications for the cold include cooling data-centers, ice-hockey arenas or air-conditioning for skyscrapers. The system is location-independent and designed to suit various boundary conditions.
Prof. Dr. Hans Gut, Managing Director of MAN Energy Solutions Schweiz AG, said: “ETES is the only storage system able to store electricity, heat and cold at the same time and also distribute them to consumers, which makes it unique.” He continued: “Due to the high overall efficiency, the modular character of the system and its low impact on the environment, ETES is a sustainable energy-storage solution that is suitable for a wide range of applications worldwide.”
The turbomachinery technology and the process design of the charging and discharging cycle are the key elements of this energy-storage system and reflect MAN Energy Solutions’ core competences. ETES features MAN’s hermetically-sealed turbo compressor HOFIM™ within the charging cycle to compress the CO2 working fluid to its supercritical state at typically 140 bar and ca. 120 °C.
(1) The HOFIM™ turbo-compressor runs on surplus energy from renewable resources, compressing CO2 in the cycle, which is heated to 120 °C.
(2) The CO2 is fed into a heat exchanger and heats the water.
(3) The hot water is stored in isolated tanks, each one at a separately-defined temperature level.
(4) Still under high pressure, the CO2 is fed into an expander, which reduces the pressure – the CO2 is liquefied and cooled.
(5/6) The liquefied CO2 is again pumped through a heat-exchange system, this time on the cold side of the system. Heat is taken from the surrounding water and ice is formed in the ice storage tank.
Source: MAN Energy Solutions