Electrification can bring about many changes which would improve living conditions of the population. However, electrification would also put a strain on the national energy supply; thus, it should be implemented in a sustainable manner. This study employs the Long-range Energy Alternatives Planning (LEAP) model to analyze future energy demand, investment costs, and CO2 emissions of three scenarios on different electrification technologies, which aim to provide electricity to unregistered rural households. The business-as-usual (BAU) scenario, which represents Thai residential sector without any increase in electrification rates, is also presented. The three scenarios are the Full Rural Electrification (RUE) through centralized grid, the Sustainable Solar Electrification (SSE), and the Sustainable Biomass Electrification (SBE). The RUE proves to be the highest cost scenario with the highest consumption and emissions, while SSE is the least expensive scenario with the least amount of energy demand. Lastly, the SBE has the least amount of emissions and can reduce the most amount of traditional biomass demand. © 2014 Asian Institute of Technology.