Topic of the final work is “ Renewable energy sources”. In my work I talk about the importance of renewable energy for the Earth itself , as it will be non-renewable energy sources eventually deplete and become inaccessible to all residents of the country . Renewable energy sources contribute to environmental protection , of course , they are neither completely clean . Especially biomass , which emits CO2 during combustion . Current technology development does not allow us to rely entirely on renewable energy sources , or predictions lead to that will increase their use in the near future . The most important renewable energy sources are : wind energy , solar energy, bio-energy , water energy. In particular, some of the technologies by which clean energy is attainable at scale today are in a kind of nascent state, and would therefore be quite pricey if implemented by the gigawatt in the level of development in which we find them today. In fact, some of the ideas that represent the greatest promise e.g., geothermal and concentrating solar power lag many decades behind others that have gotten a head start e.g., wind.