Nowadays, fossil fuels are the main sources energy from which electricity is obtained. But these sources will not last forever, so in due course renewable energies will have to replace them in this role. All energy sources have some impact on our environment. Fossil fuels — coal, oil, and natural gas — do substantially more harm than renewable energy sources by most measures, including air and water pollution, damage to public health, wildlife and habitat loss, water use, land use, and global warming emissions. A brief overview of the potential for release of some global warming substances, hazardous materials into the environment and the land and water use for different renewable energy utilization devices is presented.