Global warming, which is currently one of the greatest environmental challenges, is caused by carbon emissions. A report from the Energy Information Administration indicates that approximately 98% of CO2 emissions can be attributed to energy consumption. The trade-off between efficient and ecologically sound operation represents a major challenge faced by many organizations at present. In addition, numerous companies are currently compelled to pay a carbon tax for the resources they use and the environmental impact of their products and services. Therefore, an energy consumption system can generate actual financial payback. Green information technology involves various approaches, including power management, recycling, telecommunications, and virtualization. This paper focuses on comparing and evaluating techniques used for reducing energy consumption in virtualized environments.