Stephen T. Johnston is the growth development manager at San Diego Gas & Electric (SDG&E) and has surreptitiously become a world-leading expert on nonconductive balloons. He is a member of the IEEE Power & Energy Society. Prior to working at SDG&E, Johnston had various business and engineering roles in high-tech and semiconductor companies in the United States and the United Kingdom. He has a master's degree in physics from Rochester Institute of Technology and an MBA degree from London Business School.