Participated · Series B · Aug 2021

Malta has developed a Pumped Heat Energy Storage (PHES) system that converts electricity into stored thermal energy to provide long-duration, large-scale, cost-effective, and safe energy storage. The technology can efficiently store up to 200 hours of energy and satisfy daily or weekly load cycles, and it can also provide heat for industrial and district heating applications. Malta was spun out of X, the Moonshot Factory, and is based in Cambridge, Massachusetts. The company has partnered with Siemens Energy to develop heat pump and heat engine components for a utility-scale 100MW system designed for 10–200 hours of storage and further scaling to the GW range. Malta plans to develop its first 100MW long-duration storage project in the 2024–2025 timeframe and reports a pipeline of projects in North America, Europe, and the Middle East. The company recently closed an oversubscribed Series B round increased to over $60 million to advance its commercialization strategy. Malta Inc. develops an electro-thermal energy storage system that captures electricity, drives a heat pump to convert it into thermal energy, and stores heat in molten salt and cold in a chilled antifreeze liquid. The stored thermal energy is converted back to electricity via a heat engine when the grid needs power. Malta says its system can store electricity for days or even weeks, longer than lithium‑ion batteries. The company originated as Project Malta at Alphabet’s X and has since spun out as an independent company. Malta plans to use recent funding to work with industry partners to turn designs developed at X into industrial‑grade machinery for its first pilot system. The company’s core product targets full‑scale power grid storage and grid reliability applications.