Proceeding generations of wind turbines are becoming ever larger in size. In an attempt to optimise the size of the next generation of (horizontal axis wind turbines) HAWTs, to achieve minimum energy generation costs in commercial and wind farm applications, this project undertook the design, installation and operation of a new 1 MW turbine. WEG, a turbine designer and manufacturer has always focused on the concepts of using low mass designs to achieve low cost. It has done this by incorporating structural compliance in commercial wind turbines to minimise loads, weight and thus cost. This project aimed at the design, manufacture, installation and trial operation of a large two-bladed teetering rotor HAWT suited to sites with an annual mean wind speed in the range of 7.5 to 8.5 m/s. Market resistance to the use of two-bladed turbines on-shore meant that such a machine may not be successful commercially. The specification was thus modified to a three-bladed design 600 kW machine, which aimed at combining the visual and low noise appeal normally associated with three blades with the benefits given by the teetering rotor of a two-bladed turbine. The targeted energy cost in wind farm production was 0.06 ECU/kWh (assuming an 8% real rate of return and a 20 year lifespan).