By considering different applications, classification on produced power range and heat source
temperature is implemented. Used medium, applied equipment and the cost of the system are
investigated. Reasons on how the ORC can cost effectively fit into each system is presented. Influence of
ORC application on cost, thermal and in some cases exergy efficiencies, system payback time, internal
rate of return and net present value depending on rival technologies have been studied to support the
idea. In section ΙΙ with more details, case of rather low temperature grade ORC especially with solar
based heat source is studied. A computer model is developed to compare thermal and exergy
efficiencies, output power and turbine size factor as cost and performance indicators for different
conditions.