Small Hydroelectric Plants: The Hydraulic Auger

Small-scale hydroelectric plants are an important source of renewable energy and can actively contribute to the sustainable development of the local area, while also being cost-competitive with other renewable energy sources. This paper presents the application of a hydraulic auger used for flow rates up to 5–6 m/s and heads up to 10 m. Unlike other turbines, this equipment works by gravity with water producing torque on a transmission driving a generator connected to the auger in order to produce electricity. We present a case study on a plant located at an existing dam where, by evaluating the river’s mean daily flow, we have obtained duration curves that make it possible to determine the power and annual energy production obtainable from the plant. This is then compared with the energy that can be obtained from a plant equipped with a Banki-Mitchell turbine, highlighting that, at equal flow rates, the annual production obtainable from the two systems is nearly the same, confirming the effectiveness of the inverse auger in the energy production process. The economic aspects are then analyzed by comparing the plant construction costs with revenues from energy sales.