Sunergy is a solar-powered smart phone designed for indoor use. It has been designed to maximise battery life without sacrificing power-draining apps such as the phone’s camera, maps, Facebook, etc. Sunergy uses improved photovoltaic cells, demonstrating that solar panels can provide adequate energy without the need to expose the user and device to direct solar radiation. Although designed to function as a full-featured smart phone, Sunergy also provides a low energy mode for maximizing the phone’s battery life when needed.