Abstract: Inventive systems (e.g., turbines) for harnessing hydroelectric energy are described. The turbines include: (1) a central longitudinal shaft configured to mount and to rotate on a central axis perpendicular to a direction of fluid flow; (2) a plurality of substantially circularly arcing blades designed to couple to the shaft, each of the substantially circularly arcing blades having defined at one end one or more blade apertures; and (3) a fastening sub-assembly including fasteners, the fastening sub-assembly used for coupling the circularly arcing blades to the shaft.

Abstract: Inventive systems (e.g., turbines) for harnessing hydroelectric energy are described. The turbines, includes: (1) a central longitudinal shaft configured to mount and to rotate on a central axis perpendicular to a direction of fluid flow; (2) a plurality of arcing blades coupled with the shaft, the blades extending radially outwardly from the shaft, and the blades including an airfoil cross-section along a substantial length of the blades; and (3) a hydrodynamic cap covering a location where the arcing blades couple with the shaft such that in an operating state of the turbine, presence of the hydrodynamic cap reduces an amount of bypass area, which is area outside a region that is swept by the arcing blades.

Abstract: A novel conduit design is disclosed. The conduit includes a cylindrical body having defined therein a first aperture and a second aperture, wherein the first aperture is designed to receive a shaft of a turbine and the second aperture is sufficiently large to facilitate ingress or egress of a probe through the second aperture, and wherein the second aperture is located a distance away from the first aperture such that when a turbine is disposed through the first aperture, an entry by a probe into the cylindrical body through the second aperture is not prevented by presence of the turbine.

Abstract: A turbine is described. The turbine includes: (i) a shaft capable of rotation along its longitudinal axis and capable of connecting to an electrical generator, and the shaft having disposed thereon at least one shaft hinge; (ii) a radial arm including a first end having disposed thereon at least one first hinge; and a hinge pin that fits inside a cavity formed when at least one the shaft hinge of the shaft is in an engaged position with at least one first hinge of the radial arm, and in the engaged position the hinge pin capable of connecting the radial arm to the shaft.