Performance Characteristics of a 1 kW Scale Kite-Powered System

Abstract

A 1 kW scale kite-powered system that uses kites to convert wind energy into electrical energy has been studied to determine its performance characteristics and establish feasibility of steady-state operation. In this kite-powered system, a kite is connected to a tether that transmits the generated aerodynamic forces on the kite to a power conversion system on the ground. The ground-based power conversion system consists of a rocking arm coupled to a Sprag clutch, flywheel, and electrical generator. Governing equations describing the dynamical motion of the kite, tether, and power conversion mechanism were developed assuming an inflexible, straight-line tether. A steady-state analysis of the kite aerodynamics was incorporated into the dynamical equations of the kite-powered system. The governing equations were solved numerically using a Runge–Kutta scheme to assess how performance parameters of the system such as output power, cycle time, and tether tension varied with wind speed, kite area, and aerodynamic characteristics of the kite. The results showed that a 1 kW scale system is feasible using the proposed design concept with a kite area of 25 m2 and wind speeds of 6 m/s. Preliminary efforts to build and test a working 1 kW scale kite-powered demonstrator are also reported.