This project is dedicated to a development of electricity production from the low-enthalpy geothermal reservoirs. The prime interest is reservoirs that are characterized by low-temperature of heat source located in deep saline aquifers with a high permeable rock. Usually, energy production from these resources is not economical by using a conventional binary power plant approach. This is a study of a new system that utilizes a single-well technology and working on supercritical power cycle. The wellbore energy conversion system is operating with Zero Mass Withdrawal (ZMW) principle, which implies no geo-fluid pumping to the surface facility. This study introduces analyses of three main subsystems of the power unit. The heat extraction subsystem (HES) is located at the reservoir depth. The power generation subsystem is represented by a power cycle,operating on carbon dioxide supercritical cycle.