The global energy landscape is undergoing a crucial shift brought on by increased fossil fuel demand, environmental damage, and the need to tackle climate change. Traditional fossil fuel and nuclear energy systems have been generally dependable in the past, although there are ever-increasing worries about carbon emissions, environmental hazard, and resource availability. Renewable energy technologies including solar, wind, hydro, geothermal, and biomass represent scalable, sustainable, and low-cost alternatives as a result of technological advancements and reduced costs. Nevertheless, challenges relating to storage capabilities, intermittency of supply, and infrastructural integration remain. Furthermore, non-conventional technologies including tidal, wave, ocean thermal, micro-hydro, and second-generation bioenergy, are advancing and will provide additional diversity in energy sources in due course. This review highlights the performance, economics, social and environmental implications, and sustainability of traditional, renewable, and non-conventional energy systems. It is concluded that renewable energy represents the most immediate and practical pathway for sustainable energy transitions, while non-conventional technology can also be complementary as technologies and policies develop.