Various embodiments herein relate to systems for powering electrochromic windows in a building. Systems may include photovoltaic panels configured to generate electrical power, energy storage device(s) configured for storing generated power, and one or more controllers on a network of electrochromic windows that are configured to receive power from the energy storage device(s) and power tint transitions in one or more electrochromic windows. Systems may include various additional circuit components described herein for regulating and/or controlling the generation, storage, and application of electric power. The systems and techniques described herein can be used to design networks of electrochromic windows that are hybrid-solar or off-the-grid (“OTG”).