Recently, telecom operators are interested in discovering new future growth engines that utilize digital technology, away from existing mobile, internet and media services. In particular, the energy field is expected to expand new opportunities centering on intelligent and converged services that utilize artificial intelligence, Cloud, Big data, and Internet of Things technology, while increasing interest in eco-friendly power generation and breakthrough efficiency improvements. In this regard, this study conducted a case study focusing on smart energy service of KT. KT's smart energy service maximizes the use of ICT to solve energy problems such as deepening global climate change and increasing energy consumption. It also provides energy use diagnosis as well as forecasts and alternatives through analysis of big data collected by production, consumption and transaction areas. Through implementing KT-MEG, an integrated energy service platform KT has achieved not only an increase in sales, but also the enhancement of its global and eco-friendly corporate image. In particular, KT has dramatically changed its previous service promotion method, organization operation and service delivery system for the new business. Specifically, KT has differentiated the customers experience through providing integrated service throughout the entire processes from energy production to consumption. From the organizational viewpoint, KT has operated ambidextrous organizations for the smart energy business and separated it from the existing organizational system. Finally, for the rapid spread of the market, KT had provided a disruptive innovation services for small and medium sized companies. As the business boundary has been collapsing and technological paradigm has dramatically been changing, this case provide insights for companies to transform and evolve their business strategy in appropriate way.