A turbine includes a stack of substantially parallel disks, the rotation of which causes rotation of a shaft. The disks are separated by peripheral spacers, each peripheral spacer having the shape of an airfoil. Each peripheral spacer defines a chord which is angled radially inward, towards the axis of rotation of the disk. The peripheral spacers are located only in the vicinity of the periphery of the disk. Air, or other fluid, entering the turbine engages the airfoil shaped peripheral spacers, and the flow of air generates lift, and associated drag, causing the energy of the fluid to be more efficiently converted into mechanical, and ultimately, electrical power. The turbine is especially useful in harnessing wind energy for the generation of electric power.