Malta Inc. launches Spanish thermal energy storage pilot site

Massachusetts-based thermal energy storage company Malta Inc. on Monday signed an agreement to develop a 14 MWh commercial-scale demonstration plant for its molten-salt based technology in Puertollano, in the Spanish municipality of Ciudad Real.

Malta had announced its intent to install its LDES technology in Spain last summer, signing a memorandum of understanding with BBVA which involved the Bilbao-based bank committing to a PPA for electricity from the project.

The US company was spun out of the X “Moonshot Factory” set up by Google owner Alphabet and its partners include Spanish utility Cox and the Breakthrough Energy Ventures clean energy initiative led by tech titans and entrepreneurs Bill Gates, Marc Zuckerberg, Jeff Bezos, Jack Ma, and Richard Branson.

Malta’s technology leverages a steam-based heat pump system. The planned plant will use a closed molten salt and steam system to store electricity. Known as the Steam Energy Management and Storage system, the technology can be integrated with energy infrastructure or operate on a standalone basis, providing clean, reliable power and heat on a large scale.

The Cambridge-based business said its technology’s “ability to supply both power and heat makes it the most economical alternative for a single plant.”

The Malta plant can be integrated with systems that produce excess heat and steam, to boost its evaporation process and improve efficiency.

During the charging cycle, a series-connected, multi-stage, inter-cooled heat pump produces superheated steam to heat the molten salt to 565 C. The heat pump has a claimed coefficient of performance of more than 1.6, meaning it can produce more than 1.6 heat units for each unit of electrical energy it consumes.

The heat is stored in the molten salt, and cold is stored in water for anywhere between eight hours and several days. The salt then transfers the heat to water to produce superheated steam, which flows through a steam turbine to produce electricity or is extracted for heat and steam applications at a pressure of up to 180 bar and at a temperature of 550 C.

From pv magazine España.