Renewable Energy Technologies and their Impact on Sustainable Energy Generation, Climate Change Mitigation, and the Global Energy System. Renewable energy sources such as solar energy, wind energy, hydro power and geothermal energy are attracting more attention and investment as they have the potential to reduce GHG emissions and replace fossil fuels. In this research paper, we look at recent advances in renewable technologies, their impact on the environment, their economic feasibility and the challenges associated with widespread adoption. We also look at how renewable energy can help address the increasing demand for energy and combat climate change.