Increased CO² emissions caused by households and industry, climate change, and rising energy prices are among the most pressing issues of the present and the future. IT managers cannot turn a blind eye to these problems either. The aim of the following discussion is to examine, within the scope of a scientific bachelor's thesis, both the operational and strategic applications of Green IT technologies regarding their economic and ecological viability for companies. The central question is: Is the use of Green IT economically sensible, and does it lead to a reduction in energy consumption and CO² emissions? Furthermore, various global labels for IT energy efficiency will be analyzed in terms of their differences and similarities.