Premier Energies, one of India’s largest integrated solar manufacturers, has signed a binding term sheet with RCT India, part of Germany’s RCT Group, to set up a joint venture for battery energy storage system (BESS) manufacturing in Telangana. The company disclosed the development in a regulatory filing to the BSE and the NSE on September 10. The move marks Premier Energies’ first major push beyond solar cells and modules, the business that has defined the company since it was founded three decades ago.