STEAG Energy Services (India) Pvt. Ltd. (SESI) is a subsidiary of STEAG Energy Services GmbH, part of one of Germany's largest electricity generators. Established in 2001 and headquartered in Noida, Uttar Pradesh, SESI draws on over 80 years of global experience in power plant engineering and operation.

The company specializes in a range of energy services, including the design, construction, and modernization of fossil fuel, nuclear, and renewable energy facilities. SESI also manages operations for power plants, overseeing around 11,000 MW of installed capacity worldwide. Additionally, it offers consultancy services and develops IT solutions, providing over 2,000 systems for plant planning and performance optimization. SESI operates the world's most advanced regeneration plant for power station catalysts in the United States.

With a workforce of over 1,000 employees and revenues exceeding $500 million, SESI plays a significant role in the energy services sector, serving a diverse clientele focused on enhancing plant performance and environmental compliance.