A generator for harvesting energy from flowing water is disclosed. The generator harvests electrostatic energy as well as mechanical kinetic energy from the flowing water. In one aspect, the generator includes a plurality of blades arranged in a radially outward fashion. Each blade includes an electrode and a surface layer for receiving flowing water carrying triboelectric charges. The flowing water affects a flow of electrons between the electrode and ground. In another aspect, the generator includes a first member with a first electrode, and a second member coupled to the first member about an axis. The second member includes a second electrode, and a surface layer between the first electrode and the second electrode. The second member is rotatable with respect to the axis to change triboelectric charges on the electrodes, and to affect a flow of electrons between the electrodes.