East Nusa Tenggara Province is the lowest number of electrification than the other province in Indonesia. The number of electrification in East Nusa Tenggara Province is only 61,90%. In consequence East Nusa Tenggara Province should increase amount of power plant capacity to scale up number electrification and full-fill electricity demand. However, the increase amount of power plant must pay attention to environmental impact, by utilize renewable energy that has been proven more ecofriendly. East Nusa Tenggara Province have geothermal energy potential about 1.343 MWe. LEAP will be used as a tools in this research to predict fulfillment of electricity demand by exploit geothermal potential, using two different scenario that is Business as Usual (BAU) scenario and Renewable Energy (REN) scenario. On the scenario BAU will be added capacity Geothermal Power Plant( PLTP) of 100 MW while at the REN scenario by added capacity of 350 MW. Moreover, the capacity of the Steam Power Plat (PLTU) will reduced by 78,1 MW and diesel power plant will reduced by 171,9 MW with the aim of reducing the rate of growth of potential CO2 emissions.