Wastewater treatment plants contribute to the removal of pollutants from wastewater following the norms and regulations on the quality of the wastewater and therefore are an indispensable part of wastewater treatment and environmental protection. Each stage of wastewater treatment consumes a significant amount of energy. The need to meet rapid population growth and stricter conditions in terms of effluent quality requirements has led to an increase in energy consumption in wastewater treatment plants. Energy consumption is a bottleneck in wastewater treatment plants and, as the number of these plants in the world increases, the issues of reducing energy consumption and energy efficiency are beginning to attract attention. It also contributes to the cost increase in wastewater treatment plants. Analysis and prediction of energy consumption are key factors for energy savings. Energy consumption in wastewater treatment plants is affected by many factors. However, information on energy consumption and potential for energy recovery/production and energy efficiency in wastewater treatment plants remains very limited. This paper reviews the literature and analyzes the energy consumption in these plants and the possibility of increasing the energy efficiency of these plants through the use of renewable energy sources and energy recovery from the plant itself.