S-Energy was founded in 2001 as a spin-off from Samsung Electronics. It developed and manufactured photovoltaic modules for the first time in Korea. Though it was a medium-sized company, S-Energy has always been in leading edge in Korea solar energy industry, one of the most fluctuating markets. This case study analyzes S-Energy’s BM(Business Model) evolution process from manufacturing and selling to service providing, which shows how it survived and moved ahead in the market. S-Energy has recently done JCPenney project which built and leased solar energy systems at 2 branches in California, USA. The project gives S-Energy 3 meaningful experiences: i) implementation of electricity providing business not to power producer but to end-user, ii) securement of high project feasibility at initiation phase by using US federal and state government’s new and renewable energy support programs. iii) acquirement of capabilities to design and implement a new business model(BM innovation). This case study shows how S-Energy has tackled solar energy industry’s opportunities and threats and how it has built a service business model through JCPenney project.