The purpose of the Task is to investigate which technologies are the most appropriate now and into 2030 for solar-derived hot water, considering the full spectrum of global economic development. The Task will predominately focus on the development path and best practices for two technologies which, we believe, are likely to play the biggest role in the solar hot water market in 2030: solar thermal thermosyphon systems and solar photovoltaic (PV) self-consumption hot water heating systems. Both technologies avoid pumped circulation, require little maintenance, and have relatively low up-front capital costs, so they will clearly be strong contenders for deployment in 2030. Both technologies also offer the potential for further development, via innovative ‘smart’ control systems and real-time monitoring and integration with other residential and commercial energy systems.