Nimbus Power Systems, a Groton-based startup, has announced a significant partnership with Toshiba Energy Systems & Solutions Corp. to develop a 'pure hydrogen fuel cell stack' for heavy-duty applications. This fuel cell stack aims to power buses, trucks, and stationary systems while producing only water vapor as a byproduct, positioning it as an emissions-free alternative to traditional diesel engines. The 3.5-year joint development agreement between Nimbus and Toshiba will enable the companies to expand production in both Connecticut and Japan. Nimbus co-founder Michael Gorman expressed enthusiasm about collaborating with Toshiba, a renowned player in fuel cell technology. This partnership is expected to hasten the commercialization of the technology. As part of the agreement, Nimbus plans to grow its workforce while also raising $2.5 million for further research and development. The recent successful pre-seed fundraising round led by Connecticut Innovations indicates strong support for Nimbus's innovative approach to fuel cell technology. Toshiba Energy Systems & Solutions Corp., a subsidiary of the Japanese technology giant Toshiba Corp., brings substantial expertise to the partnership, enhancing the prospects for the successful development and deployment of the pure hydrogen fuel cell stack.