Power-to-Salt

Energy storage with power-to-salt (PTX_SALT) can support the transition towards a green and sustainable energy sector. By integrating a PTX_SALT energy storage, a significant optimization of a system’s flexibility and efficiency can be achieved – both for industrial size plants and for utility scale projects.

There is a high demand for large scale energy storages to balance the increased renewable energy share of the energy mix. Aalborg CSP has many years of experience with high temperature storage technology and molten salt systems and offers customized Power-to-Salt (PTX_SALT) solutions. PTX_SALT can, on demand, enable green power supply, which can be used for power production for both daily and weekly load shifting in the electricity grid as well as for constant power supply for the well-known PTX technologies such as hydrogen and methanol production. Moreover, it can be used to generate high temperature steam for industrial purposes. In both steam and electricity generation, it is also possible to generate heating from the residual steam condensate, e.g., for district heating.

PTX_SALT utilizes the sustainable mass of molten salt as storage medium of high temperature energy in the range of up to 565º C. Electricity from solar and wind turbines can be stored in a two-tank molten salt energy storage system after which the energy, on demand, is converted back to steam, to be used for green electricity production, green steam or green heating. This solution offers a much-needed flexibility to a volatile energy system and creates integration and balance between energy systems and sectors.

Heat exchanger design ensures reliable long-term thermal storage

The excess power is stored in the salt by means of an electrical salt heater and stored in two molten salt storage tanks. From there, steam and electricity can be produced on-demand with an integrated molten salt and steam system using a Header Coil steam generator. The Header Coil technology is a fundamental building block for reliable long-term thermal storage. The Aalborg CSP Header Coil heat exchanger technology is designed to withstand high pressure, high duty, and transient operation. Moreover, the technology meets the large requirements for thermal performance as well as the requirement for a fast ramp-up when needed. Finally, the technology is the only existing heat exchanger type with high long-term reliability and efficiency under cyclical load conditions, which is a critical point of focus for PTX_SALT plants.

A bankable and scalable PTX solution based on proven technology

The molten salt technology has been utilized within the CSP (Concentrated Solar Power) industry for decades. Experience from existing molten salt storage and header-coil equipment has proven the technology to be scalable, more economical, and bankable compared to other large scale energy storage technologies commercialized to date. This likewise form the basis of future conversions of existing coal fired power plants.