Hydropower generation from drainpipes. An analysis for small buildings

Hydropower plants produce clean electricity, exploiting the motion of flowing water, Kinetic energy, deriving from the transformation of the potential energy possessed by a water body located to a certain altitude, is converted into electrical energy by means of hydraulic turbines connected to electric generators. Recently, there is the tendency to develop smaller hydropower plants, spatially diffused to realize flexible electrical grids making load balancing easily varying as needed. In this work, we investigate a technical solution to harvest energy from drainpipes on the side of small buildings that carries rainwater down from the roof to the ground. To this aim, a pilot plant was built at the Laboratory of Environmental and Maritime Hydraulics (LIDAM), University of Salerno, Italy. Instantaneous developed power and power peak are derived, given the geometry of the system and the flow rate at the drainpipe outlet. Finally, some concluding remarks are given.