Malta Inc. is developing a long-duration, utility-scale pumped heat energy storage (PHES) technology. Malta’s PHES system converts power to heat while charging, and while discharging reconverts this stored heat to dispatchable electric and thermal energy. It will demonstrate flexibility services to and from the grid, using molten salt thermal storage proven worldwide in almost 20GWhe of commercially implemented molten salt storage capacity in solar thermal electric plants; this represents a total electric discharge power of over 3GWe by the end of 2020. Malta is charging its molten salt storage with electricity that drives a high temperature heat pump and significantly increases the resulting round trip charge / discharge efficiency.

Malta’s long-duration storage:

·        Can be deployed at large scale in the range of many 100MWe

·        Can provide long-duration storage capability from 10 hours to multiple days, while providing arbitrage and reserve power, and avoiding renewable energy curtailment

·        Can provide competitive flexibility services and system benefits for the electricity system. Based on a closed thermal air-cooled gas turbine cycle, Malta storage provides the same grid stabilization services currently secured by fossil thermal plants, including rotating synchronous inertia and frequency control, and can provide these services both while charging and discharging

·        Can decouple charging and discharging power capacity 

Malta Inc. spun out from Google X, Alphabet’s “moonshot factory,” in 2018, with initial funding led by Breakthrough Energy Ventures (BEV), the fund founded by Bill Gates.  Alfa Laval, the leading manufacturer of heat exchangers globally, invested into that financing round as did Concord New Energy, an independent power producer focused on wind and solar projects. Malta has recently closed a $50 million Series B capital raise led by Proman AG, a Switzerland-headquartered integrated petrochemical company. Other participants were BEV and Alfa Laval, showing strong insider support for the company, as well as Dustin Moskowitz. 

Michael Geyer

Senior Technical Advisor for Malta Inc on Pumped Heat Electricity Storage