Abstract: An inline hydro electric generation system for harnessing the potential energy of water passing in existing water pipes is provided. The inline hydro electric generation system comprises a housing upon which a rotatable impeller with a plurality of impeller blades is mounted. The housing is affixed to a water pipe so that water passes from the water pipe into the housing subsequently initiating the impeller to mechanically rotate. The impeller is advantageously designed so that only one impeller blade is submerged under water as the impeller is mechanically rotated. An electrical generator is axially coupled to the impeller so that when the impeller rotates, the electrical generator generates electrical power. Subsequently, the water is departs from the housing and is returned into the water pipe to continue its route to its intended recipients. The inline hydro electric generation system provides a low cost and environmentally friendly alternative to conventional energy generation systems.