The design and performance analysis of a self-sustaining, solar-driven reaction steam turbine are presented. The reaction turbine, placed horizontally, consists of two concentric cylinders with the outer one rotating with respect to the stationery inner cylinder, providing a compact and agile design. The inner cylinder, constantly filled and replenished with water, hosts conically shaped holes to allow a constant stream of feed water into the clearance between the two cylinders. With means of the thermal energy provided by the solar collector, water in the clearance will produce superheated steam that will be released in the form of steam jets causing rotational velocity, through a set of pressure relief valves placed at the surface of the outer cylinder. The main advantage of this turbine unit is the production of constant torque that is independent of temperature, with an efficiency of around 3.7%. (C) 2014 Elsevier Ltd. All rights reserved.