This chapter deals with power potential studies of a SHP. Estimation of power generation is the basic parameter of a hydro project. Power potential of a project directly depends on the discharge. The estimation of discharge data at the project site has been described in a separate chapter. How the stream flow data is utilised to work out the installed capacity, unit size and power generation of a project has been briefly explained. The flow duration curve which is used for the purpose of estimating discharge for power generation is normally developed for a particular year which is generally taken as 75% dependable year for a small hydro project. The procedure is illustrated with two case studies: one a power house at the toe of a storage dam and the other of a run-of-river scheme.