This story was originally published by Inside Climate News and is reproduced here as part of the Climate Desk collaboration. Inside a cinder block office building perhaps best known for the Hindu temple and table tennis club next door, a startup company is testing what may be one of the hottest new developments in clean energy technology. At the back of a small warehouse laboratory buzzing with fans and motors, an MIT spinoff company called Electrified Thermal Solutions is operating something its founders call the Joule Hive, a thermal battery the size of an elevator.