Ammonia is a vector for a future cleaner energy system. It can be used in combustion devices for electricity generation and as fuel for transport. This work covers technology and measurements for combustion devices for power generation and propulsion.The emerging low emission energy system will depend on a range of energy vectors or fuels, for electricity, heating, storage and transport. Each has advantages and shortcomings, qualifying it for certain roles and applications. Liquid ammonia offers a higher energy density than liquid hydrogen, but is heavier. This book describes the current knowledge around ammonia combustion systems used for power and heat. Chapters cover global distribution of ammonia, measurements of ammonia combustion, combustion systems for ammonia-fuelled gas furnaces and boilers, for gas turbines and other propulsion devices, economics, regulations and international scenarios, as well as unsolved challenges.