News Summary

Fourth Power, a startup based in Cambridge, Massachusetts, is pioneering a new form of long-duration energy storage with its cutting-edge thermal batteries. Utilizing superheated liquid tin and argon-filled chambers, these batteries aim to provide a cost-effective alternative to traditional energy storage methods like lithium-ion batteries and natural gas power plants. The technology involves heating carbon blocks in insulated chambers with electricity from the grid. When energy is needed, the system pumps molten tin through graphite pipes, capturing its infrared light to convert back into electricity. The startup has secured $20 million in a Series A Plus funding round, led by Munich Re Ventures, with participation from Breakthrough Energy Ventures and DCVC. This funding will support the development of a 1-megawatt-hour demonstration battery. Fourth Power projects that its thermal batteries could eventually store electricity at $25 per kilowatt-hour, significantly undercutting the cost of current lithium-ion options. The company is currently conducting extensive testing on smaller systems and plans to deliver commercial-scale batteries by 2028.