Cost saving potential in small wind using new tower materials and manufacturing processes

Small wind turbines have a high potential to be part of a decentralized renewable energy system. Though costs are high and profitability is still low. This paper offers developers ideas on how to enhance product and processes. For several years now the small wind industry has been expected to reach a tipping point with an increase in sales volume and a drop in production costs. This assumption is being analyzed in this paper and further saving potentials in small wind turbine production costs are outlined. Based on small wind market reports in several countries a global market analysis for small wind turbines in the range of 1 kW to 5 kW has been performed. From the findings a relevant set of manufacturers have been selected to study manufacturing methods and development trends. The learning curve model was applied to three manufacturers. The global market segment has a size of 22 000 small wind turbines annually with China, the United States and Great Britain as leadin g countries. The sales of market leaders can be estimated to be between 1000 and 2000 units a year. The tower is found to be the part with the major saving potentials. Measures to lower production and installation cost include centrifugal casted, segmented fiberglass towers and slip-joint techniques to connect the tower segments. In the midterm the learning curve model predicts a price level for a grid-connected small wind turbine with a 3.5 m diameter rotor of 4000 EUR.