Kolkata-based Vikram Solar is the largest solar module manufacturer in India (by capacity) with 2.5 GW module manufacturing capacity annually and the second-largest solar energy company in India by revenue. The company's primary business focus is manufacturing solar PV modules and also carries out engineering, procurement and construction services and operations and maintenance of solar power plants. They have technological partnerships with Fraunhofer Institute for Solar Energy Systems (ISE), IIEST (India), French Alternative Energies and Atomic Energy Commission (CEA). Vikram Solar runs extended in-house reliability test programs on their panels and substantiates them with established reliability models before offering customers their industry leading warranty terms.